Software Resume Tips:

A software resume should clearly show a candidate's technical skills. To achieve this, add the Technical Summary or Technical Expertise section to your resume. Further break this section into subcategories for a quick scan of your knowledge of programs and applications.

Fortunately, software resumes have a very simple format. The key to writing an effective resume is to put yourself into the head of the prospective hiring manager or human resources recruiter.

Keep it focused

Keep a strong focus on your goals in the field of software, incorporating parts of your background to illustrate them. A statement of your goals is one of the clearest indicators to a prospective employer of whether or not there might be a match.

For example include the following that is applicable to you

• technical certifications
• hardware
• operating systems
• networking/protocols
• programming/languages
• Web applications
• database applications

Highlight some of your soft skills in a Career Summary section to add a personality to your software resume. Remember your resume should be short enough, yet should be able to effectively showcase your achievements. Do not make it excessively lengthy.

Technical/computer or other qualification in an software resume should consist course content in brief, the duration, the institute and also the result. This domain could also consist of the projects done including platform used ( Front-end and Backend) which add a value to the job applied for and correspondingly any qualifications like personality development, marketing diploma or in general research or studies being associated with.

Highlight your Accomplishments

Show how your performance resulted favoured the company's good. Highlight your initiatives and performances that resulted in enhanced efficiency, faster work, monetary savings, etc. Focus on your most impressive technical projects/accomplishments.

Keywords

The keywords for any software resume depends on your job target and experience. Specific programs and applications are often used as keywords in case of a technical resume.

Remember :

1. Always format your experience in order of time elapsed order (chronological) your experience from your most recent job to the earlier jobs.
2. Avoid elementary information like hobbies and interests. Instead strengths or skills could be furnished to give a corporate image to the Resume.

Sample Software Resume

This sample software resume will give you a quick start on building an effective and optimized resume for your job application. Visitors can feel free to customize and edit our sample software resume as per their requirement for job application. We hope that our sample software resume will go a long way in portraying your abilities and skillsets efficiently.

CORE  JAVA FAQ’s :

1. What does "wrapping" an object mean?  

2. How to pass commandline arguments in main function through Eclipse Tools (editors). 

3. How many methods to read numbers and characters and what should be used.

4. what is the use of static data member? 

5. Is null a keyword? if not what is it? 

6. What exactly is the difference between between throw and throws? If both are used for the same purpose then why are both needed instead of one? 

7. When We should use Synchronization in Java and when we should not? 

8. How an interface can be implemented using polymorphism?Why multiple inheritence is not used in Java? 

9. How can we restrict a class so that no instance creation of class possible without declaring the class as Abstract ? 

10. What are the difference between Legacy classes and Collection other than Synchronized? 

JAVA OOPS FAQ’s :

1. What are advantages of inner class  ?

2. What is an inline class?

3. What is the purpose/uses of run-time polymorphism? Is dynamic binding only way to achieve run-time polymorphism?

4. Serializable is used to read or write the object and find the state of an object. What is the use of finding the state of an object, Explain with an example?

5. What is the use of abstract classes? How will we decide in a scenario, whether we have to use abstract class or interface?

EJB FAQ’s :

1. Which are the jar files that need to be externally added to run a simple java program that accesses a session bean in EJB 2.0, using Jboss 4.X application server? 

2. What are the serious problems you had faced while using EJB's ?

3. How are parameters passed to a method of a distributed object using RMI-IIOP? 

4. What is the difference between ejbstore and ejbload?

5. Entity bean is an abstract class and its local and home interfaces also extends an abstact class. So how can we instantiate home or local interface?

6. What is "reentrant"? Why we use this in the deployment descriptor? Explain with an example?

7. In cluster domain in weblogic with 4 managed server. cluster enabled stateless bean is created & deployed. Inside the bean, how to get server name programmatically in which the bean instance is created ?

8. How to make a call to EJB a local instead of remote and what is the role of session facade in this procedure?

9. What happens if the client object and the remote object are running in different JVMs, but on the same physical machine?

10. If something your're passing to a remote method isn't Serializable, is this a compile-time or runtime failure?

JSP FAQ’s :

1. What is JSP Fragment? 

2. How to generate a graph using real time data in JSP?

3. Where do you declare methods in JSP?

4. Where do you use exception implicit object in JSP?

5. How to disable browser "Back" and "Forward" button from a JSP page?

6. Can we use main method inside JSP? Why?

7. How do you create Http Session that never times out ?

8. What is the valid value for the body-content element in the TLD file?

9. How do you manage all the request from your servlet? How it will be thread safe?

10. How can you store ArrayList values in a session obj? Explain?

11. How do you write custom tags like tag library?

12. How to maintain values inside form field while uploading image using JSP?

ASP.NET Interview Questions

1. What do I need to create and run an ASP.NET application?

Windows 2000, Windows Server 2003 or Windows XP. ASP.NET, which can be either the redistributable (included in the .NET SDK) or Visual Studio .NET. 1. Where can I download the .NET SDK? .NET SDK can be obtained here. (You have to install the Microsoft .NET Framework Version 1.1 Redistributable Packagebefore installing the .NET SDK.)

2. Are there any free IDEs for the .NET SDK?

 Microsoft provides Visual Studio 2005 Express Edition Beta for free. Of particular interest to the ASP.NET developers would be the Visual Web Developer 2005 Express Edition Beta 2 available as a free download.  The ASP.NET Web Matrix Project (supported by Microsoft) is a free IDE for developing ASP.NET applications and is available here.  There is also a free open-source UNIX version of the Microsoft .NET development platform called Mono available for download here. o Another increasingly popular Open Source Development Environment for .NET is the #develop (short for SharpDevelop) available for download here.

3. When was ASP.NET released? ASP.NET is a part of the .NET framework which was released as a software platform in 2002.

4. Is a new version coming up?

ASP.NET 2.0, Visual Studio 2005 (Whidbey), Visual Web Developer 2005 Express Edition are the next releases of Microsoft's Web platform and tools. They have already been released as Beta versions. They are scheduled to be released in the week of November 7, 2005.

5. Explain Namespace.

Namespaces are logical groupings of names used within a program. There may be multiple namespaces in a single application code, grouped based on the identifiers’ use. The name of any given identifier must appear only once in its namespace.

6. List the types of Authentication supported by ASP.NET. o Windows (default) o Forms o Passport o None (Security disabled)

7. What is CLR? Common Language Runtime (CLR) is a run-time environment that manages the execution of .NET code and provides services like memory management, debugging, security, etc. The CLR is also known as Virtual Execution System (VES).

8. What is CLI? The CLI is a set of specifications for a runtime environment, including a common type system, base class library, and a machine-independent intermediate code known as the Common Intermediate Language (CIL). (Source: Wikipedia.)

9. List the various stages of Page-Load lifecycle.

 Init()  Load()  PreRender()  Unload()

10. Explain Assembly and Manifest.

An assembly is a collection of one or more files and one of them (DLL or EXE) contains a special metadata called Assembly Manifest. The manifest is stored as binary data and contains details like versioning requirements for the assembly, the author, security permissions, and list of files forming the assembly. An assembly is created whenever a DLL is built. The manifest can be viewed programmatically by making use of classes from the System.Reflection namespace. The tool Intermediate Language Disassembler (ILDASM) can be used for this purpose. It can be launched from the command prompt or via Start> Run.

11. What is Shadow Copy?

 In order to replace a COM component on a live web server, it was necessary to stop the entire website, copy the new files and then restart the website. This is not feasible for the web servers that need to be always running. .NET components are different. They can be overwritten at any time using a mechanism called Shadow Copy. It prevents the Portable Executable (PE) files like DLLs and EXEs from being locked. Whenever new versions of the PEs are released, they are automatically detected by the CLR and the changed components will be automatically loaded. They will be used to process all new requests not currently executing, while the older version still runs the currently executing requests. By bleeding out the older version, the update is completed.

12. What is DLL Hell? DLL hell is the problem that occurs when an installation of a newer application might break or hinder other applications as newer DLLs are copied into the system and the older applications do not support or are not compatible with them. .NET overcomes this problem by supporting multiple versions of an assembly at any given time. This is also called side-by-side component versioning.

13. Explain Web Services.

Web services are programmable business logic components that provide access to functionality through the Internet. Standard protocols like HTTP can be used to access them. Web services are based on the Simple Object Access Protocol (SOAP), which is an application of XML. Web services are given the .asmx extension.

14. Explain Windows Forms. Windows Forms is employed for developing Windows GUI applications. It is a class library that gives developers’ access to Windows Common Controls with rich functionality. It is a common GUI library for all the languages supported by the .NET Framework.

15. What is Post back?

When an action occurs (like button click), the page containing all the controls within the tag performs an HTTP POST, while having itself as the target URL. This is called Post back.

16. Explain the differences between server-side and client-side code?

Server side scripting means that all the script will be executed by the server and interpreted as needed. Client side scripting means that the script will be executed immediately in the browser such as form field validation, clock, email validation, etc. Client side scripting is usually done in VBScript or JavaScript. Since the code is included in the HTML page, anyone can see the code by viewing the page source. It also poses as a possible security hazard for the client computer.

17. Enumerate the types of Directives.

 @ Page directive 

@ Import directive 

@ Implements directive 

@ Register directive 

@ Assembly directive 

@ OutputCache directive 

@ Reference directive

18. What is Code-Behind?

Code-Behind is a concept where the contents of a page are in one file and the server-side code is in another. This allows different people to work on the same page at the same time and also allows either part of the page to be easily redesigned, with no changes required in the other. An Inherits attribute is added to the @ Page directive to specify the location of the Code-Behind file to the ASP.NET page.

19. Describe the difference between inline and code behind. Inline code is written along side the HTML in a page. There is no separate distinction between design code and logic code. Code-behind is code written in a separate file and referenced by the .aspx page.

20. List the ASP.NET validation controls?

 RequiredFieldValidator ,RangeValidator ,CompareValidator ,RegularExpressionValidator, CustomValidator  and ValidationSummary

21. What is Data Binding?

Data binding is a way used to connect values from a collection of data (e.g. DataSet) to the controls on a web form. The values from the dataset are automatically displayed in the controls without having to write separate code to display them.

22. Describe Paging in ASP.NET?

The DataGrid control in ASP.NET enables easy paging of the data. The AllowPagingproperty of the DataGrid can be set to True to perform paging. ASP.NET automatically performs paging and provides the hyperlinks to the other pages in different styles, based on the property that has been set for PagerStyle.Mode.

23. Should user input data validation occur server-side or client-side? Why?

All user input data validation should occur on the server and minimally on the client-side, though it is a good way to reduce server load and network traffic because we can ensure that only data of the appropriate type is submitted from the form. It is totally insecure. The user can view the code used for validation and create a workaround for it. Secondly, the URL of the page that handles the data is freely visible in the original form page. This will allow unscrupulous users to send data from their own forms to your application. Client-side validation can sometimes be performed where deemed appropriate and feasible to provide a richer, more responsive experience for the user.

24. What is the difference between Server.Transfer and Response.Redirect?

 Response.Redirect: This tells the browser that the requested page can be found at a new location. The browser then initiates another request to the new page loading its contents in the browser. This results in two requests by the browser. o Server.Transfer: It transfers execution from the first page to the second page on the server. As far as the browser client is concerned, it made one request and the initial page is the one responding with content. The benefit of this approach is one less round trip to the server from the client browser. Also, any posted form variables and query string parameters are available to the second page as well.

26. What is an interface and what is an abstract class?

In an interface, all methods must be abstract (must not be defined). In an abstract class, some methods can be defined. In an interface, no accessibility modifiers are allowed, whereas it is allowed in abstract classes.

27. Session state vs. View state?

In some cases, using view state is not feasible. The alternative for view state is session state. Session state is employed under the following situations: 

Large amounts of data - View state tends to increase the size of both the HTML page sent to the browser and the size of form posted back. Hence session state is used. o Secure data - Though the view state data is encoded and may be encrypted, it is better and secure if no sensitive data is sent to the client. Thus, session state is a more secure option. o Problems in serializing of objects into view state - View state is efficient for a small set of data. Other types like DataSet are slower and can generate a very large view state.

28. Can two different programming languages be mixed in a single ASPX file?

ASP.NET’s built-in parsers are used to remove code from ASPX files and create temporary files. Each parser understands only one language. Therefore mixing of languages in a single ASPX file is not possible.

29. Is it possible to see the code that ASP.NET generates from an ASPX file?

By enabling debugging using a statement in Web.config, the generated code can be viewed. The code is stored in a CS or VB file (usually in the\%SystemRoot%\Microsoft.NET\Framework\v1.0.nnnn\Temporary ASP.NET Files).

30. Can a custom .NET data type be used in a Web form?

This can be achieved by placing the DLL containing the custom data type in the application root's bin directory and ASP.NET will automatically load the DLL when the type is referenced.  

ABAP/4

Q: When we create a customer the information is updated in structure RF02D and the some tables like KNA1 are updated. How can we find the tables for master data transactions?
A: Go to ABAP Workbench -> Overview -> application hierarchy - SAP -> follow the customizing based tree for your application. Double click on a lowest hierarchy level to get for the correct marked development class. Here you can find all the tables, views, logical databases etc. used for a system operation.    

B D C

Q: Our ABAP program is working properly in Foreground. Can Ischedule it forbackground processing on the weekend?
A: SAP standard program RSBDCSUB helps you to schedule the job. Create a variant for RSBDCSUB with the BDC session name.

Q: How can wesend amail to the user intimating him that hisreport/BDC is completed in background?
A: You can use FUNCTION RS_SEND_MAIL_FOR_SPOOLLIST
If Unix is being used, you may send a report to any internet mail with the following:

REPORT ZSNDMAIL .
DATA: COMND(200) type c.
DATA: RESULT(200) type c occurs 100 with header line.
PARAMETERS: FILE(60) type c lower case default '/sapdata/sd_outbound/testmail.dat'.
PARAMETERS: SUBJECT(60) type c lower case. 
PARAMETERS: EMAIL(60) type c lower case.
INITIALIZATION. 
TRANSLATE EMAIL TO LOWER CASE.
START-OF-SELECTION. 
TRANSLATE EMAIL TO LOWER CASE. 
CONCATENATE 'cat' FILE '| elm -s "' subject '"' email into comnd seperated by space. 
CALL 'SYSTEM' ID 'COMMAND' FIELD comnd 'TAB' FIELD UNIX_RESULTS-*SYS*. 
Loop at Results. 
write: /1 results. 
endloop 
end-of-selection.

Q: We get the total number of pages as expected by using 'SAPSCRIPT-FORMPAGES' in a duplex layout. In our case duplex case is always 'Terms & Conditions'. Wedo not want the number ofpages asin duplex printing. What is the best possible solution?
A: On the Terms & Conditions page, Change the Page counter mode to 'HOLD' to keep the page counter from incrementing when you print the Term & Conditions.

Q: Can IPrint a logo on an Invoice?
A: Save a Logo using Paintshop Pro or Corel Draw as Tiff file. Use RSTXLDMC to convert the logo to standard text in SapScript. When the program is executed, the path and file name have to be correctly specified.
Process could be like the following:
Run RSTXLDMC
Enter file name C:\MAIL\COMPLOGO.TIF
Resolution for Tiff file
Absolute X-position
Absolute Y-position
Absolute positioning
Reserved height
Shift to right
UOM = CM
Text title
Line width for text = 132
Text name ZHEX-MACRO-COMPLOGO
Text ID ST
Text language = E
Postscript scaling
Width & Height according to PS scaling
Number of Tiff gray levels (2,4,9) 2
Then Create a new window 'COMP' with attributes;
Window COMP description Company Logo
Window type CONST
Left margin 7.00 CH window width 10.00 CH
Upper margin LN window height 8.00 LN
Finally in the text element , mention
/: INCLUDE 'ZHEX-MACRO-COMPLOGO' OBJECT TEXT ID ST LANGUAGE 'E'.
Please note that if object name is not indicated as 'ZHEX...', the logo may not be printed!
You will not be able to see the logo in a test print. The same will be printed in actual printout.
If you are using two logos in the same layout, the names of the logos should be unique. Say 'ZHEX-MACRO-LOGO1' and 'ZHEX-MACRO-LOGO2'. Else all the information will be overwritten.
If the logo is not EXACTLY TIFF 6.0 , the same will not be printed.
See OSS notes 5995, 18045, 39031 for some inputs.

Q: We want tomove a SAP table to anAccess table using TABLE_EXPORT_TO_MSACCESS_RFC
Importing parameters are
DBNAME
DEST
FLG_APPEND
FLG_POPUP
LANGU
The table has three columns:
TABNAM
MANDT
SDATA
We have no Exporting parameters.
How shall we set the parameters?
A: Install the PS utilities, which are part of SAPGUI install CD. You may run report RIACCESS from SE38. Go to SALE -> Communication -> Define RFC Destination. Setup two RFC destinations PS_ACCESS_1 and PS_ACCESS_2 and will have to get them to point to wdpsastr.exe and wdpsatab.exe respectively. Then execute RIACCESS and choose PS_ACCESS_1 to generate access tables. Please note that Access only supports tables with up 255 fields.

Q: We want anRFC do the following transactions - MB1A, MB1C,>MB01 .
A: Call the RFC INBOUND_IDOC_PROCESS with IDOC_CONTROL and IDOC_DATA. The structure in the field sdata in the IDOC_DATA are e1mbxyh and e1mbxyi.

Transports

Q: In a Dev instance, we want totransport a modification to alayout set from one client to another. What is the best way?
A: use transaction SE71. Choose Utilities->Copy from Client. Layout sets need not be transported between clients , via transport requests DEVKxxxxxx.

Q: We need tokeep track of the transports that need to flow through to other systems (ie, DEV, TST, TRN, PRD etc). Is there a way do this?
A: SAPCRAFT enables you to control the CTS from DEV system. This keeps track of all transports at all stages and enables you to allocate Import, export and Authorization functions to specific user.

Q:1 We created an EDI Vendor and created all required output conditions. Howeverno IDOC is generated when PO is printed. Why?
A: Go to Header->output for the PO. The output type shall be '6'. The status shall be '1'. If the status is '0' check the timing. If the status is '2' , go to 'GOTO->Processing Log' and the explanation for non-generation of IDOC can be seen.

Q: How can we create / upload IDOC'sfrom legacy system to SAP?
A: Third party tool Mercator may be used to convert Legacy files to Idoc format. Mercator provides an IDOC tree import facility, SAP provides the export facility. You can transfer the Idoc layouts from SAP to Mercator automatically and then map.

Q: We want toreceive an outbound EDI855 IDOC only if E2EDP20 -scheduling confirmation segmentis present. Else get an "error" status preventing triggering the EDI subsystem.
A: User exit logic has to be added in function IDOC_INPUT_ORDRSP.

# Set up a test flag and set it off when the IDOC header is read.
# Turn the flag ON when the EDP20 segment is read.
# Interrogate this flag when the next segment after EDP20 in the same IDOC comes in. If it is on ,you have an EDP20 coming in.
# Issue an error status 51 with suitable message for whichever condition you don't want the IDOC to be processed, This will stop the IDOC from posting.

Q: Where ever PO is sent to the vendor via EDI, we want anacknowledgement of the PO by vendor. Which fields are updated and what should be my procedure?
A: Execute Program: IDOC_INPUT_ORDRSP
Process code: ORDR
Message type: ORDRSP
IDOC: ORDERS01
The confirmation process allows the supplier to return an acknowledgment. Only Dates and quantities can be changed The information is stored in the PO and can be viewed via Item->Confirmation->Overview. The PO can be flagged as 'confirmation required' so that Pos without acknowledgement receipt can be monitored. Control keys and tolerances (days and quantities) have to be customized.

Q: OurIDOC remains in status 51 ( not posted) while testing ALE setup by passing DEBMAS02 Idocs. The message 'Field KNA1-BRSCH is not an input field'. This is the Industry key. What are we missing?
A: Go to IMG - menu path IMG->LogisticsGeneral-> Logistics Basic Data: Business partners->Customers-> Control->Define Account groups and field selection for customer.
Select sold-to or ship-to. Select General Data. Select control and double click. Industry key is found here. Change the option to 'Optional Entry'.
Check OSS 5599. You may have to update view V_T078D also.

Q: We are calling transaction VL01 inbatch input to create deliveries using a program for delivery due list. How ever we areunable to create deliveries for transport stock orders. Why?
a: Batch-inputs can not be used to fill the "delivery due list" screen because it is not a dynpro. This is a standard SAP report. A SAP report (check with "System -> Status") may be called using SUBMIT sentence with the appropriate options . It is preferred to call a report than create a Batch-input program.

Q: What are somesample Direct input data transfer programs?
A: In MM for Material Master data - RMDATIND
FI - for Accounting Documents - RFBIBL00
PP - for Independent requirements - RM06IN00
CA - for Classification data - RCCLBI03

Q: We specify thelogical database. And we want a field that is not present in any of the tables defaulted in logical database. How can we want to add thisadditional field from a different table?
A: . Presume you have a

logical database 
table 1
table 2
table 3

Define the required field as additional field say fld of table 1, table 2 or   table 3  
and then in the code section define.

Perform get_f1d(zxxxxxxx) using f1d.
Form zxxxxxxx could be like;
Form get_f1d using f. 
Select * from where 'conditions'

Q: We need todownload an internal table to the Presentation Server(local workstation). Whenever we run the program, the same file has to be saved as a separatefile in sequential order. Ex: 0001.txt, 0002.txt etc. Where can we store the last file number?
A: SAP has a table TVARV for storing the variants.
A record may be created in TVARV for all the programs that require this kind of incremental records.
For Ex: the record could be 100Zmm10001 MM sequence rec where first part consists of client code and the program being run. Client code is required because TVARV does not has a field for client code. The second part is the description indicating the purpose what the record is created. This entire string may be posted in the Name field (char - 30).
The Type field ( char- 1) may be populated with P or S (Parameter or Selection)
Low field (char- 45) may be populated with '0001' when run first time and increment it by one in your program for downloading of the internal table.

Others

Q: How can we use CAD with SAP?
A: Third party tools from Eigner + Partner provide interfaces to SAP. Another third party software - Fastlook Plus from Kamel Software enables you to view all of the Autocad formats.

Q: How can I accessSAP through Internet?
A: SAP has its own Internet transaction Server (ITS) . Other products include Haht, WebObjects, NetDynamics etc. Each product has its' own architecture.
However to access the database, access paths SAP GUI or RFC Channel have to be used.

Q: How can wetransport the standard text?
A: Refer note 3355 in OSS for a complete explanation. The SAPscript objects that should be transported must be written in a transport request.
The entries are as follows:
R3TR FORM NAME (NAME = Name of the layout set)
R3TR STYL NAME (NAME = Name of the style)
R3TR TEXT OBJECT,NAME,ID,L
(OBJECT = Text object, NAME = Text name, ID = Text ID, L = Text language)
If you want to transport a number of texts, you can use report RSTXTRAN to insert the individual text keys into a correction. The transport request must be entered and released via the transport system.

Q: How to findwhat transactions a particularuser was running for a given period in the past (Eg: from 1^st of a month )
A: You may use the transaction - STAT.

Q: We wantprotect/lock a field so that only selected people can change the value while others can only read. How to set the authorizations?
A: Create an authorization object for change mode. Loop at screen in the user exit and set input to 0. Check the user based on sy-uname and the authorization. Decide whether input should be 0 or 1.

Q: How tolock an user defined transaction for some time during which no user can access the same?
A: Use transaction SM01. Scroll through the transactions and check against the transaction to be locked. And after the maintenance is over, go back to SM01 and uncheck the same to unlock.

• Organizations vary considerably in how they assign responsibility for QA and testing. Sometimes they're the combined responsibility of one group or individual. Also common are project teams that include a mix of testers and developers who work closely together, with overall QA processes monitored by project managers. It will depend on what best fits an organization's size and business structure.

 What are some recent major computer system failures caused by software bugs?

• Software problems in the automated baggage sorting system of a major airport in February 2008 prevented thousands of passengers from checking baggage for their flights. It was reported that the breakdown occurred during a software upgrade, despite pre-testing of the software. The system continued to have problems in subsequent months.
• News reports in December of 2007 indicated that significant software problems were continuing to occur in a new ERP payroll system for a large urban school system. It was believed that more than one third of employees had received incorrect paychecks at various times since the new system went live the preceding January, resulting in overpayments of $53 million, as well as underpayments. An employees' union brought a lawsuit against the school system, the cost of the ERP system was expected to rise by 40%, and the non-payroll part of the ERP system was delayed. Inadequate testing reportedly contributed to the problems.
• In November of 2007 a regional government reportedly brought a multi-million dollar lawsuit against a software services vendor, claiming that the vendor 'minimized quality' in delivering software for a large criminal justice information system and the system did not meet requirements. The vendor also sued its subcontractor on the project.
• In June of 2007 news reports claimed that software flaws in a popular online stock-picking contest could be used to gain an unfair advantage in pursuit of the game's large cash prizes. Outside investigators were called in and in July the contest winner was announced. Reportedly the winner had previously been in 6th place, indicating that the top 5 contestants may have been disqualified.
• A software problem contributed to a rail car fire in a major underground metro system in April of 2007 according to newspaper accounts. The software reportedly failed to perform as expected in detecting and preventing excess power usage in equipment on a new passenger rail car, resulting in overheating and fire in the rail car, and evacuation and shutdown of part of the system.
• Tens of thousands of medical devices were recalled in March of 2007 to correct a software bug. According to news reports, the software would not reliably indicate when available power to the device was too low.
• A September 2006 news report indicated problems with software utilized in a state government's primary election, resulting in periodic unexpected rebooting of voter checkin machines, which were separate from the electronic voting machines, and resulted in confusion and delays at voting sites. The problem was reportedly due to insufficient testing.
• In August of 2006 a U.S. government student loan service erroneously made public the personal data of as many as 21,000 borrowers on it's web site, due to a software error. The bug was fixed and the government department subsequently offered to arrange for free credit monitoring services for those affected.
• A software error reportedly resulted in overbilling of up to several thousand dollars to each of 11,000 customers of a major telecommunications company in June of 2006. It was reported that the software bug was fixed within days, but that correcting the billing errors would take much longer.
• News reports in May of 2006 described a multi-million dollar lawsuit settlement paid by a healthcare software vendor to one of its customers. It was reported that the customer claimed there were problems with the software they had contracted for, including poor integration of software modules, and problems that resulted in missing or incorrect data used by medical personnel.
• In early 2006 problems in a government's financial monitoring software resulted in incorrect election candidate financial reports being made available to the public. The government's election finance reporting web site had to be shut down until the software was repaired.
• Trading on a major Asian stock exchange was brought to a halt in November of 2005, reportedly due to an error in a system software upgrade. The problem was rectified and trading resumed later the same day.
• A May 2005 newspaper article reported that a major hybrid car manufacturer had to install a software fix on 20,000 vehicles due to problems with invalid engine warning lights and occasional stalling. In the article, an automotive software specialist indicated that the automobile industry spends $2 billion to $3 billion per year fixing software problems.
• Media reports in January of 2005 detailed severe problems with a $170 million high-profile U.S. government IT systems project. Software testing was one of the five major problem areas according to a report of the commission reviewing the project. In March of 2005 it was decided to scrap the entire project.
• In July 2004 newspapers reported that a new government welfare management system in Canada costing several hundred million dollars was unable to handle a simple benefits rate increase after being put into live operation. Reportedly the original contract allowed for only 6 weeks of acceptance testing and the system was never tested for its ability to handle a rate increase.
• Millions of bank accounts were impacted by errors due to installation of inadequately tested software code in the transaction processing system of a major North American bank, according to mid-2004 news reports. Articles about the incident stated that it took two weeks to fix all the resulting errors, that additional problems resulted when the incident drew a large number of e-mail phishing attacks against the bank's customers, and that the total cost of the incident could exceed $100 million.
• A bug in site management software utilized by companies with a significant percentage of worldwide web traffic was reported in May of 2004. The bug resulted in performance problems for many of the sites simultaneously and required disabling of the software until the bug was fixed.
• According to news reports in April of 2004, a software bug was determined to be a major contributor to the 2003 Northeast blackout, the worst power system failure in North American history. The failure involved loss of electrical power to 50 million customers, forced shutdown of 100 power plants, and economic losses estimated at $6 billion. The bug was reportedly in one utility company's vendor-supplied power monitoring and management system, which was unable to correctly handle and report on an unusual confluence of initially localized events. The error was found and corrected after examining millions of lines of code.
• In early 2004, news reports revealed the intentional use of a software bug as a counter-espionage tool. According to the report, in the early 1980's one nation surreptitiously allowed a hostile nation's espionage service to steal a version of sophisticated industrial software that had intentionally-added flaws. This eventually resulted in major industrial disruption in the country that used the stolen flawed software.
• A major U.S. retailer was reportedly hit with a large government fine in October of 2003 due to web site errors that enabled customers to view one anothers' online orders.
• News stories in the fall of 2003 stated that a manufacturing company recalled all their transportation products in order to fix a software problem causing instability in certain circumstances. The company found and reported the bug itself and initiated the recall procedure in which a software upgrade fixed the problems.
• In August of 2003 a U.S. court ruled that a lawsuit against a large online brokerage company could proceed; the lawsuit reportedly involved claims that the company was not fixing system problems that sometimes resulted in failed stock trades, based on the experiences of 4 plaintiffs during an 8-month period. A previous lower court's ruling that "...six miscues out of more than 400 trades does not indicate negligence." was invalidated.
• In April of 2003 it was announced that a large student loan company in the U.S. made a software error in calculating the monthly payments on 800,000 loans. Although borrowers were to be notified of an increase in their required payments, the company will still reportedly lose $8 million in interest. The error was uncovered when borrowers began reporting inconsistencies in their bills.
• News reports in February of 2003 revealed that the U.S. Treasury Department mailed 50,000 Social Security checks without any beneficiary names. A spokesperson indicated that the missing names were due to an error in a software change. Replacement checks were subsequently mailed out with the problem corrected, and recipients were then able to cash their Social Security checks.
• In March of 2002 it was reported that software bugs in Britain's national tax system resulted in more than 100,000 erroneous tax overcharges. The problem was partly attributed to the difficulty of testing the integration of multiple systems.
• A newspaper columnist reported in July 2001 that a serious flaw was found in off-the-shelf software that had long been used in systems for tracking certain U.S. nuclear materials. The same software had been recently donated to another country to be used in tracking their own nuclear materials, and it was not until scientists in that country discovered the problem, and shared the information, that U.S. officials became aware of the problems.
• According to newspaper stories in mid-2001, a major systems development contractor was fired and sued over problems with a large retirement plan management system. According to the reports, the client claimed that system deliveries were late, the software had excessive defects, and it caused other systems to crash.
• In January of 2001 newspapers reported that a major European railroad was hit by the aftereffects of the Y2K bug. The company found that many of their newer trains would not run due to their inability to recognize the date '31/12/2000'; the trains were started by altering the control system's date settings.
• News reports in September of 2000 told of a software vendor settling a lawsuit with a large mortgage lender; the vendor had reportedly delivered an online mortgage processing system that did not meet specifications, was delivered late, and didn't work.
• In early 2000, major problems were reported with a new computer system in a large suburban U.S. public school district with 100,000+ students; problems included 10,000 erroneous report cards and students left stranded by failed class registration systems; the district's CIO was fired. The school district decided to reinstate it's original 25-year old system for at least a year until the bugs were worked out of the new system by the software vendors.
• A review board concluded that the NASA Mars Polar Lander failed in December 1999 due to software problems that caused improper functioning of retro rockets utilized by the Lander as it entered the Martian atmosphere.
• In October of 1999 the $125 million NASA Mars Climate Orbiter spacecraft was believed to be lost in space due to a simple data conversion error. It was determined that spacecraft software used certain data in English units that should have been in metric units. Among other tasks, the orbiter was to serve as a communications relay for the Mars Polar Lander mission, which failed for unknown reasons in December 1999. Several investigating panels were convened to determine the process failures that allowed the error to go undetected.
• Bugs in software supporting a large commercial high-speed data network affected 70,000 business customers over a period of 8 days in August of 1999. Among those affected was the electronic trading system of the largest U.S. futures exchange, which was shut down for most of a week as a result of the outages.
• In April of 1999 a software bug caused the failure of a $1.2 billion U.S. military satellite launch, the costliest unmanned accident in the history of Cape Canaveral launches. The failure was the latest in a string of launch failures, triggering a complete military and industry review of U.S. space launch programs, including software integration and testing processes. Congressional oversight hearings were requested.
• A small town in Illinois in the U.S. received an unusually large monthly electric bill of $7 million in March of 1999. This was about 700 times larger than its normal bill. It turned out to be due to bugs in new software that had been purchased by the local power company to deal with Y2K software issues.
• In early 1999 a major computer game company recalled all copies of a popular new product due to software problems. The company made a public apology for releasing a product before it was ready.
• The computer system of a major online U.S. stock trading service failed during trading hours several times over a period of days in February of 1999 according to nationwide news reports. The problem was reportedly due to bugs in a software upgrade intended to speed online trade confirmations.
• In April of 1998 a major U.S. data communications network failed for 24 hours, crippling a large part of some U.S. credit card transaction authorization systems as well as other large U.S. bank, retail, and government data systems. The cause was eventually traced to a software bug.
• January 1998 news reports told of software problems at a major U.S. telecommunications company that resulted in no charges for long distance calls for a month for 400,000 customers. The problem went undetected until customers called up with questions about their bills.
• In November of 1997 the stock of a major health industry company dropped 60% due to reports of failures in computer billing systems, problems with a large database conversion, and inadequate software testing. It was reported that more than $100,000,000 in receivables had to be written off and that multi-million dollar fines were levied on the company by government agencies.
• A retail store chain filed suit in August of 1997 against a transaction processing system vendor (not a credit card company) due to the software's inability to handle credit cards with year 2000 expiration dates.
• In August of 1997 one of the leading consumer credit reporting companies reportedly shut down their new public web site after less than two days of operation due to software problems. The new site allowed web site visitors instant access, for a small fee, to their personal credit reports. However, a number of initial users ended up viewing each others' reports instead of their own, resulting in irate customers and nationwide publicity. The problem was attributed to "...unexpectedly high demand from consumers and faulty software that routed the files to the wrong computers."
• In November of 1996, newspapers reported that software bugs caused the 411 telephone information system of one of the U.S. RBOC's to fail for most of a day. Most of the 2000 operators had to search through phone books instead of using their 13,000,000-listing database. The bugs were introduced by new software modifications and the problem software had been installed on both the production and backup systems. A spokesman for the software vendor reportedly stated that 'It had nothing to do with the integrity of the software. It was human error.'
• On June 4 1996 the first flight of the European Space Agency's new Ariane 5 rocket failed shortly after launching, resulting in an estimated uninsured loss of a half billion dollars. It was reportedly due to the lack of exception handling of a floating-point error in a conversion from a 64-bit integer to a 16-bit signed integer.
• Software bugs caused the bank accounts of 823 customers of a major U.S. bank to be credited with $924,844,208.32 each in May of 1996, according to newspaper reports. The American Bankers Association claimed it was the largest such error in banking history. A bank spokesman said the programming errors were corrected and all funds were recovered.
• On January 1 1984 all computers produced by one of the leading minicomputer makers of the time reportedly failed worldwide. The cause was claimed to be a leap year bug in a date handling function utilized in deletion of temporary operating system files. Technicians throughout the world worked for several days to clear up the problem. It was also reported that the same bug affected many of the same computers four years later.
• Software bugs in a Soviet early-warning monitoring system nearly brought on nuclear war in 1983, according to news reports in early 1999. The software was supposed to filter out false missile detections caused by Soviet satellites picking up sunlight reflections off cloud-tops, but failed to do so. Disaster was averted when a Soviet commander, based on what he said was a '...funny feeling in my gut', decided the apparent missile attack was a false alarm. The filtering software code was rewritten.  

Does every software project need testers?
While all projects will benefit from testing, some projects may not require independent test staff to succeed.

Which projects may not need independent test staff? The answer depends on the size and context of the project, the risks, the development methodology, the skill and experience of the developers, and other factors. For instance, if the project is a short-term, small, low risk project, with highly experienced programmers utilizing thorough unit testing or test-first development, then test engineers may not be required for the project to succeed.

In some cases an IT organization may be too small or new to have a testing staff even if the situation calls for it. In these circumstances it may be appropriate to instead use contractors or outsourcing, or adjust the project management and development approach (by switching to more senior developers and agile test-first development, for example). Inexperienced managers sometimes gamble on the success of a project by skipping thorough testing or having programmers do post-development functional testing of their own work, a decidedly high risk gamble.

For non-trivial-size projects or projects with non-trivial risks, a testing staff is usually necessary. As in any business, the use of personnel with specialized skills enhances an organization's ability to be successful in large, complex, or difficult tasks. It allows for both a) deeper and stronger skills and b) the contribution of differing perspectives. For example, programmers typically have the perspective of 'what are the technical issues in making this functionality work?'. A test engineer typically has the perspective of 'what might go wrong with this functionality, and how can we ensure it meets expectations?'. Technical people who can be highly effective in approaching tasks from both of those perspectives are rare, which is why, sooner or later, organizations bring in test specialists.

Why does software have bugs?

• miscommunication or no communication - as to specifics of what an application should or shouldn't do (the application's requirements).
• software complexity - the complexity of current software applications can be difficult to comprehend for anyone without experience in modern-day software development. Multi-tier distributed systems, applications utilizing mutliple local and remote web services applications, data communications, enormous relational databases, security complexities, and sheer size of applications have all contributed to the exponential growth in software/system complexity.
• programming errors - programmers, like anyone else, can make mistakes.
• changing requirements (whether documented or undocumented) - the end-user may not understand the effects of changes, or may understand and request them anyway - redesign, rescheduling of engineers, effects on other projects, work already completed that may have to be redone or thrown out, hardware requirements that may be affected, etc. If there are many minor changes or any major changes, known and unknown dependencies among parts of the project are likely to interact and cause problems, and the complexity of coordinating changes may result in errors. Enthusiasm of engineering staff may be affected. In some fast-changing business environments, continuously modified requirements may be a fact of life. In this case, management must understand the resulting risks, and QA and test engineers must adapt and plan for continuous extensive testing to keep the inevitable bugs from running out of control - see 'What can be done if requirements are changing continuously?' in the LFAQ. Also see information about 'agile' approaches such as XP, in Part 2 of the FAQ.
• time pressures - scheduling of software projects is difficult at best, often requiring a lot of guesswork. When deadlines loom and the crunch comes, mistakes will be made.
• egos - people prefer to say things like:

    'no problem' 
    'piece of cake'
    'I can whip that out in a few hours'
    'it should be easy to update that old code'
  
   instead of:
    'that adds a lot of complexity and we could end up
       making a lot of mistakes'
    'we have no idea if we can do that; we'll wing it'
    'I can't estimate how long it will take, until I
       take a close look at it'
    'we can't figure out what that old spaghetti code
       did in the first place'
  
   If there are too many unrealistic 'no problem's', the
   result is bugs.
   
  

• poorly documented code - it's tough to maintain and modify code that is badly written or poorly documented; the result is bugs. In many organizations management provides no incentive for programmers to document their code or write clear, understandable, maintainable code. In fact, it's usually the opposite: they get points mostly for quickly turning out code, and there's job security if nobody else can understand it ('if it was hard to write, it should be hard to read').
• software development tools - visual tools, class libraries, compilers, scripting tools, etc. often introduce their own bugs or are poorly documented, resulting in added bugs.

How can new Software QA processes be introduced in an existing organization?

• A lot depends on the size of the organization and the risks involved. For large organizations with high-risk (in terms of lives or property) projects, serious management buy-in is required and a formalized QA process is necessary.
• Where the risk is lower, management and organizational buy-in and QA implementation may be a slower, step-at-a-time process. QA processes should be balanced with productivity so as to keep bureaucracy from getting out of hand.
• For small groups or projects, a more ad-hoc process may be appropriate, depending on the type of customers and projects. A lot will depend on team leads or managers, feedback to developers, and ensuring adequate communications among customers, managers, developers, and testers.
• The most value for effort will often be in (a) requirements management processes, with a goal of clear, complete, testable requirement specifications embodied in requirements or design documentation, or in 'agile'-type environments extensive continuous coordination with end-users, (b) design inspections and code inspections, and (c) post-mortems/retrospectives.
• Other possibilities include incremental self-managed team approaches such as 'Kaizen' methods of continuous process improvement, the Deming-Shewhart Plan-Do-Check-Act cycle, and others.

What is verification? validation?
Verification typically involves reviews and meetings to evaluate documents, plans, code, requirements, and specifications. This can be done with checklists, issues lists, walkthroughs, and inspection meetings. Validation typically involves actual testing and takes place after verifications are completed. The term 'IV & V' refers to Independent Verification and Validation.

What is a 'walkthrough'?
A 'walkthrough' is an informal meeting for evaluation or informational purposes. Little or no preparation is usually required.

What's an 'inspection'?
An inspection is more formalized than a 'walkthrough', typically with 3-8 people including a moderator, reader, and a recorder to take notes. The subject of the inspection is typically a document such as a requirements spec or a test plan, and the purpose is to find problems and see what's missing, not to fix anything. Attendees should prepare for this type of meeting by reading thru the document; most problems will be found during this preparation. The result of the inspection meeting should be a written report. Thorough preparation for inspections is difficult, painstaking work, but is one of the most cost effective methods of ensuring quality. Employees who are most skilled at inspections are like the 'eldest brother' in the parable in 'Why is it often hard for organizations to get serious about quality assurance?'. Their skill may have low visibility but they are extremely valuable to any software development organization, since bug prevention is far more cost-effective than bug detection.

What kinds of testing should be considered?

• Black box testing - not based on any knowledge of internal design or code. Tests are based on requirements and functionality.
• White box testing - based on knowledge of the internal logic of an application's code. Tests are based on coverage of code statements, branches, paths, conditions.
• unit testing - the most 'micro' scale of testing; to test particular functions or code modules. Typically done by the programmer and not by testers, as it requires detailed knowledge of the internal program design and code. Not always easily done unless the application has a well-designed architecture with tight code; may require developing test driver modules or test harnesses.
• incremental integration testing - continuous testing of an application as new functionality is added; requires that various aspects of an application's functionality be independent enough to work separately before all parts of the program are completed, or that test drivers be developed as needed; done by programmers or by testers.
• integration testing - testing of combined parts of an application to determine if they function together correctly. The 'parts' can be code modules, individual applications, client and server applications on a network, etc. This type of testing is especially relevant to client/server and distributed systems.
• functional testing - black-box type testing geared to functional requirements of an application; this type of testing should be done by testers. This doesn't mean that the programmers shouldn't check that their code works before releasing it (which of course applies to any stage of testing.)
• system testing - black-box type testing that is based on overall requirements specifications; covers all combined parts of a system.
• end-to-end testing - similar to system testing; the 'macro' end of the test scale; involves testing of a complete application environment in a situation that mimics real-world use, such as interacting with a database, using network communications, or interacting with other hardware, applications, or systems if appropriate.
• sanity testing or smoke testing - typically an initial testing effort to determine if a new software version is performing well enough to accept it for a major testing effort. For example, if the new software is crashing systems every 5 minutes, bogging down systems to a crawl, or corrupting databases, the software may not be in a 'sane' enough condition to warrant further testing in its current state.
• regression testing - re-testing after fixes or modifications of the software or its environment. It can be difficult to determine how much re-testing is needed, especially near the end of the development cycle. Automated testing tools can be especially useful for this type of testing.
• acceptance testing - final testing based on specifications of the end-user or customer, or based on use by end-users/customers over some limited period of time.
• load testing - testing an application under heavy loads, such as testing of a web site under a range of loads to determine at what point the system's response time degrades or fails.
• stress testing - term often used interchangeably with 'load' and 'performance' testing. Also used to describe such tests as system functional testing while under unusually heavy loads, heavy repetition of certain actions or inputs, input of large numerical values, large complex queries to a database system, etc.
• performance testing - term often used interchangeably with 'stress' and 'load' testing. Ideally 'performance' testing (and any other 'type' of testing) is defined in requirements documentation or QA or Test Plans.
• usability testing - testing for 'user-friendliness'. Clearly this is subjective, and will depend on the targeted end-user or customer. User interviews, surveys, video recording of user sessions, and other techniques can be used. Programmers and testers are usually not appropriate as usability testers.
• install/uninstall testing - testing of full, partial, or upgrade install/uninstall processes.
• recovery testing - testing how well a system recovers from crashes, hardware failures, or other catastrophic problems.
• failover testing - typically used interchangeably with 'recovery testing'
• security testing - testing how well the system protects against unauthorized internal or external access, willful damage, etc; may require sophisticated testing techniques.
• compatability testing - testing how well software performs in a particular hardware/software/operating system/network/etc. environment.
• exploratory testing - often taken to mean a creative, informal software test that is not based on formal test plans or test cases; testers may be learning the software as they test it.
• ad-hoc testing - similar to exploratory testing, but often taken to mean that the testers have significant understanding of the software before testing it.
• context-driven testing - testing driven by an understanding of the environment, culture, and intended use of software. For example, the testing approach for life-critical medical equipment software would be completely different than that for a low-cost computer game.
• user acceptance testing - determining if software is satisfactory to an end-user or customer.
• comparison testing - comparing software weaknesses and strengths to competing products.
• alpha testing - testing of an application when development is nearing completion; minor design changes may still be made as a result of such testing. Typically done by end-users or others, not by programmers or testers.
• beta testing - testing when development and testing are essentially completed and final bugs and problems need to be found before final release. Typically done by end-users or others, not by programmers or testers.
• mutation testing - a method for determining if a set of test data or test cases is useful, by deliberately introducing various code changes ('bugs') and retesting with the original test data/cases to determine if the 'bugs' are detected. Proper implementation requires large computational resources.

What are 5 common problems in the software development process?

• poor requirements - if requirements are unclear, incomplete, too general, and not testable, there will be problems.
• unrealistic schedule - if too much work is crammed in too little time, problems are inevitable.
• inadequate testing - no one will know whether or not the program is any good until the customer complains or systems crash.
• featuritis - requests to pile on new features after development is underway; extremely common.
• miscommunication - if developers don't know what's needed or customer's have erroneous expectations, problems can be expected.

What are 5 common solutions to software development problems?

• solid requirements - clear, complete, detailed, cohesive, attainable, testable requirements that are agreed to by all players. In 'agile'-type environments, continuous close coordination with customers/end-users is necessary to ensure that changing/emerging requirements are understood.
• realistic schedules - allow adequate time for planning, design, testing, bug fixing, re-testing, changes, and documentation; personnel should be able to complete the project without burning out.
• adequate testing - start testing early on, re-test after fixes or changes, plan for adequate time for testing and bug-fixing. 'Early' testing could include static code analysis/testing, test-first development, unit testing by developers, built-in testing and diagnostic capabilities, automated post-build testing, etc.
• stick to initial requirements where feasible - be prepared to defend against excessive changes and additions once development has begun, and be prepared to explain consequences. If changes are necessary, they should be adequately reflected in related schedule changes. If possible, work closely with customers/end-users to manage expectations. In 'agile'-type environments, initial requirements may be expected to change significantly, requiring that true agile processes be in place.
• communication - require walkthroughs and inspections when appropriate; make extensive use of group communication tools - groupware, wiki's, bug-tracking tools and change management tools, intranet capabilities, etc.; ensure that information/documentation is available and up-to-date - preferably electronic, not paper; promote teamwork and cooperation; use protoypes and/or continuous communication with end-users if possible to clarify expectations.

What is software 'quality'?
Quality software is reasonably bug-free, delivered on time and within budget, meets requirements and/or expectations, and is maintainable. However, quality is obviously a subjective term. It will depend on who the 'customer' is and their overall influence in the scheme of things. A wide-angle view of the 'customers' of a software development project might include end-users, customer acceptance testers, customer contract officers, customer management, the development organization's management/accountants/testers/salespeople, future software maintenance engineers, stockholders, magazine columnists, etc. Each type of 'customer' will have their own slant on 'quality' - the accounting department might define quality in terms of profits while an end-user might define quality as user-friendly and bug-free.

What is 'good code'?
'Good code' is code that works, is reasonably bug free, and is readable and maintainable. Some organizations have coding 'standards' that all developers are supposed to adhere to, but everyone has different ideas about what's best, or what is too many or too few rules. There are also various theories and metrics, such as McCabe Complexity metrics. It should be kept in mind that excessive use of standards and rules can stifle productivity and creativity. 'Peer reviews', 'buddy checks' pair programming, code analysis tools, etc. can be used to check for problems and enforce standards.
For example, in C/C++ coding, here are some typical ideas to consider in setting rules/standards; these may or may not apply to a particular situation:

• minimize or eliminate use of global variables.
• use descriptive function and method names - use both upper and lower case, avoid abbreviations, use as many characters as necessary to be adequately descriptive (use of more than 20 characters is not out of line); be consistent in naming conventions.
• use descriptive variable names - use both upper and lower case, avoid abbreviations, use as many characters as necessary to be adequately descriptive (use of more than 20 characters is not out of line); be consistent in naming conventions.
• function and method sizes should be minimized; less than 100 lines of code is good, less than 50 lines is preferable.
• function descriptions should be clearly spelled out in comments preceding a function's code.
• organize code for readability.
• use whitespace generously - vertically and horizontally
• each line of code should contain 70 characters max.
• one code statement per line.
• coding style should be consistent throught a program (eg, use of brackets, indentations, naming conventions, etc.)
• in adding comments, err on the side of too many rather than too few comments; a common rule of thumb is that there should be at least as many lines of comments (including header blocks) as lines of code.
• no matter how small, an application should include documentaion of the overall program function and flow (even a few paragraphs is better than nothing); or if possible a separate flow chart and detailed program documentation.
• make extensive use of error handling procedures and status and error logging.
• for C++, to minimize complexity and increase maintainability, avoid too many levels of inheritance in class heirarchies (relative to the size and complexity of the application). Minimize use of multiple inheritance, and minimize use of operator overloading (note that the Java programming language eliminates multiple inheritance and operator overloading.)
• for C++, keep class methods small, less than 50 lines of code per method is preferable.
• for C++, make liberal use of exception handlers

What is 'good design'?
'Design' could refer to many things, but often refers to 'functional design' or 'internal design'. Good internal design is indicated by software code whose overall structure is clear, understandable, easily modifiable, and maintainable; is robust with sufficient error-handling and status logging capability; and works correctly when implemented. Good functional design is indicated by an application whose functionality can be traced back to customer and end-user requirements. (See further discussion of functional and internal design in 'What's the big deal about requirements?' in FAQ #2.) For programs that have a user interface, it's often a good idea to assume that the end user will have little computer knowledge and may not read a user manual or even the on-line help; some common rules-of-thumb include:

• the program should act in a way that least surprises the user
• it should always be evident to the user what can be done next and how to exit
• the program shouldn't let the users do something stupid without warning them.

What is SEI? CMM? CMMI? ISO? IEEE? ANSI? Will it help?

• SEI = 'Software Engineering Institute' at Carnegie-Mellon University; initiated by the U.S. Defense Department to help improve software development processes.
• CMM = 'Capability Maturity Model', now called the CMMI ('Capability Maturity Model Integration'), developed by the SEI. It's a model of 5 levels of process 'maturity' that determine effectiveness in delivering quality software. It is geared to large organizations such as large U.S. Defense Department contractors. However, many of the QA processes involved are appropriate to any organization, and if reasonably applied can be helpful. Organizations can receive CMMI ratings by undergoing assessments by qualified auditors.

       Level 1 - characterized by chaos, periodic panics, and heroic
                 efforts required by individuals to successfully
                 complete projects.  Few if any processes in place;
                 successes may not be repeatable.

       Level 2 - software project tracking, requirements management,
                 realistic planning, and configuration management
                 processes are in place; successful practices can
                 be repeated.

       Level 3 - standard software development and maintenance processes
                 are integrated throughout an organization; a Software
                 Engineering Process Group is is in place to oversee
                 software processes, and training programs are used to
                 ensure understanding and compliance.

       Level 4 - metrics are used to track productivity, processes,
                 and products.  Project performance is predictable,
                 and quality is consistently high.

       Level 5 - the focus is on continouous process improvement. The
                 impact of new processes and technologies can be
                 predicted and effectively implemented when required.


      Perspective on CMM ratings:  During 1997-2001, 1018 organizations
      were assessed.  Of those, 27% were rated at Level 1, 39% at 2,
      23% at 3, 6% at 4, and  5% at 5.  (For ratings during the period 
      1992-96, 62% were at Level 1, 23% at 2, 13% at 3, 2% at 4, and 
      0.4% at 5.)  The median size of organizations was 100 software 
      engineering/maintenance personnel; 32% of organizations were 
      U.S. federal contractors or agencies.  For those rated at 
      Level 1, the most problematical key process area was in 
      Software Quality Assurance.

• ISO = 'International Organisation for Standardization' - The ISO 9001:2000 standard (which replaces the previous standard of 1994) concerns quality systems that are assessed by outside auditors, and it applies to many kinds of production and manufacturing organizations, not just software. It covers documentation, design, development, production, testing, installation, servicing, and other processes. The full set of standards consists of: (a)Q9001-2000 - Quality Management Systems: Requirements; (b)Q9000-2000 - Quality Management Systems: Fundamentals and Vocabulary; (c)Q9004-2000 - Quality Management Systems: Guidelines for Performance Improvements. To be ISO 9001 certified, a third-party auditor assesses an organization, and certification is typically good for about 3 years, after which a complete reassessment is required. Note that ISO certification does not necessarily indicate quality products - it indicates only that documented processes are followed. Also see http://www.iso.org/ for the latest information. In the U.S. the standards can be purchased via the ASQ web site at http://www.asq.org/quality-press/
  ISO 9126 defines six high level quality characteristics that can be used in software evaluation. It includes functionality, reliability, usability, efficiency, maintainability, and portability.
• IEEE = 'Institute of Electrical and Electronics Engineers' - among other things, creates standards such as 'IEEE Standard for Software Test Documentation' (IEEE/ANSI Standard 829), 'IEEE Standard of Software Unit Testing (IEEE/ANSI Standard 1008), 'IEEE Standard for Software Quality Assurance Plans' (IEEE/ANSI Standard 730), and others.
• ANSI = 'American National Standards Institute', the primary industrial standards body in the U.S.; publishes some software-related standards in conjunction with the IEEE and ASQ (American Society for Quality).
• Other software development/IT management process assessment methods besides CMMI and ISO 9000 include SPICE, Trillium, TickIT, Bootstrap, ITIL, MOF, and CobiT.
• See the 'Other Resources' section for further information available on the web.

What is the 'software life cycle'?
The life cycle begins when an application is first conceived and ends when it is no longer in use. It includes aspects such as initial concept, requirements analysis, functional design, internal design, documentation planning, test planning, coding, document preparation, integration, testing, maintenance, updates, retesting, phase-out, and other aspects.

1. Name the divisions in a COBOL program.

   IDENTIFICATION DIVISION, ENVIRONMENT DIVISION, DATA DIVISION, PROCEDURE DIVISION.

2. What are the different data types available in COBOL?

   Alpha-numeric (X), alphabetic (A) and numeric (9).

3. What does the INITIALIZE verb do? –

   Alphabetic, Alphanumeric fields & alphanumeric edited items are set to SPACES.

   Numeric, Numeric edited items set to ZERO.

   FILLER , OCCURS DEPENDING ON items left untouched.

4. What is 77 level used for ?

5. What is 88 level used for ?

   For condition names.

6. What is level 66 used for ?

   For RENAMES clause.

7. What does the IS NUMERIC clause establish ?

   IS NUMERIC can be used on alphanumeric items, signed numeric & packed decimal items and usigned numeric & packed decimal items. IS NUMERIC returns TRUE if the item only consists of 0-9. However, if the item being tested is a signed item, then it may contain 0-9, + and - .

8. How do you define a table/array in COBOL?

   01 ARRAYS.

   05 ARRAY1 PIC X(9) OCCURS 10 TIMES.

   05 ARRAY2 PIC X(6) OCCURS 20 TIMES INDEXED BY WS-INDEX.

9. Can the OCCURS clause be at the 01 level?

   No.

10. What is the difference between index and subscript?

    Subscript refers to the array occurrence while index is the displacement (in no of bytes) from the beginning of the array. An index can only be modified using PERFORM, SEARCH & SET.

    Need to have index for a table in order to use SEARCH, SEARCH ALL.

11. What is the difference between SEARCH and SEARCH ALL?

    SEARCH - is a serial search.

    SEARCH ALL - is a binary search & the table must be sorted ( ASCENDING/DESCENDING KEY clause to be used & data loaded in this order) before using SEARCH ALL.

12. What should be the sorting order for SEARCH ALL?

    It can be either ASCENDING or DESCENDING. ASCENDING is default. If you want the search to be done on an array sorted in descending order, then while defining the array, you should give DESCENDING KEY clause. (You must load the table in the specified order).

13. What is binary search?

    Search on a sorted array. Compare the item to be searched with the item at the center. If it matches, fine else repeat the process with the left half or the right half depending on where the item lies.

14. My program has an array defined to have 10 items. Due to a bug, I find that even if the program access the 11th item in this array, the program does not abend. What is wrong with it?

    Must use Compiler  option SSRANGE if You want array bounds checking.Deafault is NOSSRANGE.

    How do you sort in a COBOL program? Give sort file definition, sort statement syntax and meaning.

15. Syntax:

    SORT file-1 ON ASCENDING/DESCENDING KEY key....

    USING file-2

    GIVING file-3.

    USING can be substituted by INPUT PROCEDURE IS para-1 THRU para-2

    GIVING can be substituted by OUTPUT PROCEDURE IS para-1 THRU para-2.

    file-1 is the sort workfile and must be described using SD entry in FILE SECTION.

    file-2 is the input file for the SORT and must be described using an FD entry in FILE SECTION and SELECT clause in FILE CONTROL.

    file-3 is the outfile from the SORT and must be described using an FD entry in FILE SECTION and SELECT clause in FILE CONTROL.

    file-1, file-2 & file-3 should not be opened explicitly.

    INPUT PROCEDURE is executed before the sort and records must be RELEASEd to the sort work file from the input procedure.

    OUTPUT PROCEDURE is executed after all records have been sorted. Records from the sort work file must be RETURNed one at a time to the output procedure.

16. How do you define a sort file in JCL that runs the COBOL program?

    Use the SORTWK01, SORTWK02,..... dd names in the step. Number of sort datasets depends on the volume of data being sorted, but a minimum of 3 is required.

17. What are the two ways of doing sorting in a COBOL program? Give the formats.

    See question 16.

18. Give the format of USING and GIVING in SORT statement. What are the restrictions with it?

    See question 16. Restrictions - Cannot massage records, canot select records to be sorted.

19. What is the difference between performing a SECTION and a PARAGRAPH?

    Performing a SECTION will cause all the paragraphs that are part of the section, to be performed.

    Performing a PARAGRAPH will cause only that paragraph to be performed.

20. What is the use of EVALUATE statement?

    Evaluate is like a case statement and can be used to replace nested Ifs. The difference between EVALUATE and case is that no 'break' is required for EVALUATE i.e. control comes out of the EVALUATE as soon as one match is made.

    
    
    VSAM

    1. What are the different types of VSAM files available?

    ESDS: Entry Sequence Data Set

    KSDS: Key Sequence Data Set

    RRDS: Relative Data Set

    2. What is IDCAMS ?

    IDCAMS is the Access Method Services program. You run the IDCAMS program and supply AMS commands thru SYSIN. (examples of AMS commands are DELETE, DEFINE, REPRO etc..).

    3. Can AMS commands be run from the TSO prompt ?

    Yes

    4. Syntax of AMS modal commands ?

    Note: these can be used only under IDCAMS and not from the TSO prompt.

    IF LASTCC(or MAXCC) >(or <,= etc..) value -

    THEN -

    DO -

    command set (such as DELETE, DEFINE etc..)

    ELSE -

    DO -

    command set

    LASTCC - Condition code from the last function(such as delete) executed

    MAXCC - Max condition code that was returned by any of the prev functions

    SET is also a valid AMS command. SET LASTCC (or MAXCC) = value

    The maximum condition code is 16. A cond code of 4 indicates a warning. A cond code of 8 is usually encountered on a DELETE of a dataset that is not present.

    5. Under IDCAMS , multiple functions can be executed, each of which returns a cond code. What will be the condition code returned to the operating system ?

    The maximum condition code generated is returned as the condition code of the IDCAMS step.

    6. What is Control Interval, Control Area ?

    Control Interval is analogous to a physical block for QSAM files. It is the unit of i/o. Must be between 512 bytes to 32 k. Usually either 2K or 4K. A larger control interval increases performance for sequential processing while the reverse is true for random access. Under CICS when a record is locked, the entire CI gets locked.

    Control area is a group of control intervals. CA is used during allocation. CA size is calculated based on the allocation type (cyl, tracks or records) and can be max of 1 cylinder

    7. What is FREESPACE ?

    Coded in the DEFINE as FREESPACE(ci ca) where ci is the percentage of each control interval to be left free for insertions, ca is the percentage of control intervals in each control area to be left empty.

    8. How do you decide on optimum values for CI, FREESPACE etc..?

    CI size should be based on record length, type of processing. Usually CI is 4K. If record length is larger(>1K), chose 6K or 8K.

    FREESPACE should be large if more number of insertions are envisaged. Usual values are (20 20) when heavy updates are expected. CI size can be calculated.

    9. Would you specify FREESPACE for an ESDS?

    No. Because you cannot insert records in an ESDS, also when you rewrite a record, it must be of the same length. Thus putting any value for freespace does not make any sense.

    10. What is SHAREOPTS ?

    SHAREOPTS is a parameter in the DEFINE and specifies how an object can be shared among users. It is coded as SHAREOPTS(a b), where a is the cross region share option ie how two or more jobs on a single system can share the file, while b is the cross system share option ie how two or more jobs on different MVSes can share the file. Usual value is (2 3).

Data Warehousing Interview Questions

1) What do you know about Datawarehousing ?
Data warehousing is used for reporting and analysis of the data. It is primarily used to analyze data. Some of the additional uses of it are extraction and retrieval of data, manage, load and manipulate data. It has various tools which can transform, load, extract and manage the data.

2) State some of the benefits of dataware housing?
These are some of the benefits of dataware housing they are: -
1) Regardless of the data source it provides common data model this feature makes analysis of data much easier.
2) Inconsistency is identified during the loading process.
3) In case there is a crash of the database, database programmer can feel comfortable because it is stored in the dataware housing.
4) It is very efficient and will not slow down the operational system.

3) What are the different interconnected layers of a dataware house?
There are four different interconnected layers they are: -
• Operational database layer
• Informational access layer
• Data access layer
• Meta data layer.

4) Explain about the top design?
In a top design model data ware house is designed in a normalized enterprise model. This is chiefly used for business intelligence and management capabilities. Data used for business purpose and management can be met through a dataware house. It is used to generate dimensional views and is known to be good and stable against business changes.

5) Explain about the time variant feature of Dataware housing?
Dataware house detects and tracks all the changes according to time. This allows a database developer to detect the changes across time which helps him to keep a log.

6) Explain about the non-volatile feature of dataware house?
Data once written and saved in dataware house is static and it can never be deleted and over written once confirmed. It will be static and read-only. This can be used for future reporting and it allows good security feature.

7) Explain some disadvantages of dataware house?
These are some of the disadvantages of dataware house: -
1) It represents a very large project with a very broad scope which is a big disadvantage.
2) Upfront costs are very huge and the duration of the project from the start to the end user is significant.
3) It is inflexible and unresponsive to the departmental needs.

8) Explain about hybrid design model?
Due to the various risks and disadvantages presented by top down and bottom down models it has become imperative that Hybrid methodologies be used. This is used for fast turn around time and enterprise wide data consistency. This uses features and benefits from top down and bottom down models.

9) Explain about the bottom up design?
Bottom up design provides the advantage of a quick turnaround. As soon as the first data marts are created business values can be returned. Some of the disadvantages caused are due to multiple versions and false truth operations. Conforming dimensions and tight management can mitigate these risks.

10) State some of the disadvantages of data ware houses?
Some of the disadvantages are as follows: -
1) Dataware house can be costly due to high maintenance of the database. It is usually not static.
2) There is always a risk of it delivering outdated results which makes it less productive.
3) A fine line exists between dataware house and operational systems.

11) What do you think about the future of dataware housing?
Dataware housing will be used by organizations to analyze their huge pool of data. With the development of various dataware house appliances performance of dataware housing applications can be improved. There would be many more apps working in accordance with the Gartner Group report which makes it much user friendly and reliable.

12) What are the general stages of use of dataware house?
These are the general stages of use: -
1) Offline operational database
2) Offline dataware house
3) Real time dataware house
4) Integrated dataware house.

These are some of the questions which might be asked they are: -
1) Explain the hierarchy of dataware house?
2) State differences between reusable transformation and Mapplet?
3) Explain about IQD file and Cognos script editor?

4) State two major differences between a dataware house and operational dataware house?
There exist two major differences they are: -
1) It integrates information from a pre existing source database
2) It is used for analysis usually for OLAP where huge amounts of data occur frequently.
5) Explain about the integrated dataware house stage?
At this stage dataware house gets updated every time a transaction occurs. The transactions performed during this time are passed back to the operational systems which records the transactions.

What are types of Facts?
Categories: Data WareHousing Interview Questions

What are non-additive facts in detail?
Categories: Data WareHousing Interview Questions

What is the difference between view and materialized view?
Categories: Data WareHousing Interview Questions

Why should you put your data warehouse on a different system than your OLTP system?
Categories: Data WareHousing Interview Questions

What are conformed dimensions?
Categories: Data WareHousing Interview Questions

What are Data Marts?
Categories: Data WareHousing Interview Questions
What is ETL?
Categories: Data WareHousing Interview Questions

What does level of Granularity of a fact table signify?
Categories: Data WareHousing Interview Questions

What is the Difference between OLTP and OLAP?
Categories: Data WareHousing Interview Questions

What are non-additive facts?
Categories: Data WareHousing Interview Questions

What are slowly changing dimensions?
Categories: Data WareHousing Interview Questions

Why are OLTP database designs not generally a good idea for a Data Warehouse?
Categories: Data WareHousing Interview Questions

What are Semi-additive and factless facts and in which scenario will you use such kinds of fact tables?
Categories: Data WareHousing Interview Questions

Check out the article Q100139 from Microsoft knowledge base and of course, there's much more information available in the net. It'll be a good idea to get a hold of any RDBMS fundamentals text book, especially the one by C. J. Date. Most of the times, it will be okay if you can explain till third normal form.

As the name indicates, denormalization is the reverse process of normalization. It's the controlled introduction of redundancy in to the database design. It helps improve the query performance as the number of joins could be reduced.

One-to-One relationship can be implemented as a single table and rarely as two tables with primary and foreign key relationships.
One-to-Many relationships are implemented by splitting the data into two tables with primary key and foreign key relationships.
Many-to-Many relationships are implemented using a junction table with the keys from both the tables forming the composite primary key of the junction table.

Both primary key and unique enforce uniqueness of the column on which they are defined. But by default primary key creates a clustered index on the column, where are unique creates a nonclustered index by default. Another major difference is that, primary key doesn't allow NULLs, but unique key allows one NULL only.

User defined datatypes let you extend the base SQL Server datatypes by providing a descriptive name, and format to the database. Take for example, in your database, there is a column called Flight_Num which appears in many tables. In all these tables it should be varchar(8). In this case you could create a user defined datatype called Flight_num_type of varchar(8) and use it across all your tables. 

See sp_addtype, sp_droptype in books online.

Bit datatype is used to store boolean information like 1 or 0 (true or false). Untill SQL Server 6.5 bit datatype could hold either a 1 or 0 and there was no support for NULL. But from SQL Server 7.0 onwards, bit datatype can represent a third state, which is NULL. 

A candidate key is one that can identify each row of a table uniquely. Generally a candidate key becomes the primary key of the table. If the table has more than one candidate key, one of them will become the primary key, and the rest are called alternate keys. 

A key formed by combining at least two or more columns is called composite key. 

A default is a value that will be used by a column, if no value is supplied to that column while inserting data. IDENTITY columns and timestamp columns can't have defaults bound to them. See CREATE DEFUALT in books online.

A transaction is a logical unit of work in which, all the steps must be performed or none. ACID stands for Atomicity, Consistency, Isolation, Durability. These are the properties of a transaction. For more information and explanation of these properties, see SQL Server books online or any RDBMS fundamentals text book.

An isolation level determines the degree of isolation of data between concurrent transactions. The default SQL Server isolation level is Read Committed. Here are the other isolation levels (in the ascending order of isolation): Read Uncommitted, Read Committed, Repeatable Read, Serializable. See SQL Server books online for an explanation of the isolation levels. Be sure to read about SET TRANSACTION ISOLATION LEVEL, which lets you customize the isolation level at the connection level.

Non-clustered index. Important thing to note: By default a clustered index gets created on the primary key, unless specified otherwise.

8060 bytes. Don't be surprised with questions like 'what is the maximum number of columns per table'. Check out SQL Server books online for the page titled: "Maximum Capacity Specifications".

Hopefully you have experience setting up cluster servers. But if you don't, at least be familiar with the way clustering works and the two clusterning configurations Active/Active and Active/Passive. SQL Server books online has enough information on this topic and there is a good white paper available on Microsoft site.

This is a very important question and you better be able to answer it if consider yourself a DBA. SQL Server books online is the best place to read about SQL Server architecture. Read up the chapter dedicated to SQL Server Architecture.

Lock escalation is the process of converting a lot of low level locks (like row locks, page locks) into higher level locks (like table locks). Every lock is a memory structure too many locks would mean, more memory being occupied by locks. To prevent this from happening, SQL Server escalates the many fine-grain locks to fewer coarse-grain locks. Lock escalation threshold was definable in SQL Server 6.5, but from SQL Server 7.0 onwards it's dynamically managed by SQL Server.

DELETE TABLE is a logged operation, so the deletion of each row gets logged in the transaction log, which makes it slow. TRUNCATE TABLE also deletes all the rows in a table, but it won't log the deletion of each row, instead it logs the deallocation of the data pages of the table, which makes it faster. Of course, TRUNCATE TABLE can be rolled back.

Check out MOLAP, ROLAP and HOLAP in SQL Server books online for more infomation.

This question is generally asked to see how current is your knowledge. Generally there is a section in the beginning of the books online titled "What's New", which has all such information. Of course, reading just that is not enough, you should have tried those things to better answer the questions. Also check out the section titled "Backward Compatibility" in books online which talks about the changes that have taken place in the new version.

Constraints enable the RDBMS enforce the integrity of the database automatically, without needing you to create triggers, rule or defaults.

Types of constraints: NOT NULL, CHECK, UNIQUE, PRIMARY KEY, FOREIGN KEY

For an explanation of these constraints see books online for the pages titled: "Constraints" and "CREATE TABLE", "ALTER TABLE"

Indexes in SQL Server are similar to the indexes in books. They help SQL Server retrieve the data quicker.

Indexes are of two types. Clustered indexes and non-clustered indexes. When you craete a clustered index on a table, all the rows in the table are stored in the order of the clustered index key. So, there can be only one clustered index per table. Non-clustered indexes have their own storage separate from the table data storage. Non-clustered indexes are stored as B-tree structures (so do clustered indexes), with the leaf level nodes having the index key and it's row locater. The row located could be the RID or the Clustered index key, depending up on the absence or presence of clustered index on the table.

If you create an index on each column of a table, it improves the query performance, as the query optimizer can choose from all the existing indexes to come up with an efficient execution plan. At the same t ime, data modification operations (such as INSERT, UPDATE, DELETE) will become slow, as every time data changes in the table, all the indexes need to be updated. Another disadvantage is that, indexes need disk space, the more indexes you have, more disk space is used.

RAID stands for Redundant Array of Inexpensive Disks, used to provide fault tolerance to database servers. There are six RAID levels 0 through 5 offering different levels of performance, fault tolerance. MSDN has some information about RAID levels and for detailed information, check out the RAID advisory board's homepage

This is a very open ended question and there could be a lot of reasons behind the poor performance of a query. But some general issues that you could talk about would be: No indexes, table scans, missing or out of date statistics, blocking, excess recompilations of stored procedures, procedures and triggers without SET NOCOUNT ON, poorly written query with unnecessarily complicated joins, too much normalization, excess usage of cursors and temporary tables.

Some of the tools/ways that help you troubleshooting performance problems are: SET SHOWPLAN_ALL ON, SET SHOWPLAN_TEXT ON, SET STATISTICS IO ON, SQL Server Profiler, Windows NT /2000 Performance monitor, Graphical execution plan in Query Analyzer.

Download the white paper on performance tuning SQL Server from Microsoft web site. Don't forget to check out sql-server-performance.com

Again this is another open ended question. Here are some things you could talk about: Preferring NT authentication, using server, databse and application roles to control access to the data, securing the physical database files using NTFS permissions, using an unguessable SA password, restricting physical access to the SQL Server, renaming the Administrator account on the SQL Server computer, disabling the Guest account, enabling auditing, using multiprotocol encryption, setting up SSL, setting up firewalls, isolating SQL Server from the web server etc.

Read the white paper on SQL Server security from Microsoft website. Also check out My SQL Server security best practices

Deadlock is a situation when two processes, each having a lock on one piece of data, attempt to acquire a lock on the other's piece. Each process  would wait indefinitely for the other to release the lock, unless one of the user processes is terminated. SQL Server detects deadlocks and terminates one user's process.

A livelock is one, where a  request for an exclusive lock is repeatedly denied because a series of overlapping shared locks keeps interfering. SQL Server detects the situation after four denials and refuses further shared locks. A livelock also occurs when read transactions monopolize a table or page, forcing a write transaction to wait indefinitely.

Check out SET DEADLOCK_PRIORITY and "Minimizing Deadlocks"  in SQL Server books online. Also check out the article Q169960 from Microsoft knowledge base.

Blocking happens when one connection from an application holds a lock and a second connection requires a conflicting lock type. This forces the second connection to wait, blocked on the first. 

Read up the following topics in SQL Server books online: Understanding and avoiding blocking, Coding efficient transactions.

Many of us are used to craeting databases from the Enterprise Manager or by just issuing the command: CREATE DATABAE MyDB. But what if you have to create a database with two filegroups, one on drive C and the other on drive D with log on drive E with an initial size of 600 MB and with a growth factor of 15%? That's why being a DBA you should be familiar with the CREATE DATABASE syntax. Check out SQL Server books online for more information.

SQL Server can be started from command line, using the SQLSERVR.EXE. This EXE has some very important parameters with which a DBA should be familiar with. -m is used for starting SQL Server in single user mode and -f is used to start the SQL Server in minimal confuguration mode. Check out SQL Server books online for more parameters and their explanations.

DBCC CHECKDB, DBCC CHECKTABLE, DBCC CHECKCATALOG, DBCC CHECKALLOC, DBCC SHOWCONTIG, DBCC SHRINKDATABASE, DBCC SHRINKFILE etc. But there are a whole load of DBCC commands which are very useful for DBAs. Check out SQL Server books online for more information.

Statistics determine the selectivity of the indexes. If an indexed column has unique values then the selectivity of that index is more, as opposed to an index with non-unique values. Query optimizer uses these indexes in determining whether to choose an index or not while executing a query. 

Some situations under which you should update statistics:
1) If there is significant change in the key values in the index
2) If a large amount of data in an indexed column has been added, changed, or removed (that is, if the distribution of key values has changed), or the table has been truncated using the TRUNCATE TABLE statement and then repopulated
3) Database is upgraded from a previous version

Look up SQL Server books online for the following commands: UPDATE STATISTICS, STATS_DATE, DBCC SHOW_STATISTICS, CREATE STATISTICS, DROP STATISTICS, sp_autostats, sp_createstats, sp_updatestats

There are lots of options available, you have to choose your option depending upon your requirements. Some of the options you have are: BACKUP/RESTORE, dettaching and attaching databases, replication, DTS, BCP, logshipping, INSERT...SELECT, SELECT...INTO, creating INSERT scripts to generate data.

Types of backups you can create in SQL Sever 7.0+ are Full database backup, differential database backup, transaction log backup, filegroup backup. Check out the BACKUP and RESTORE commands in SQL Server books online. Be prepared to write the commands in your interview. Books online also has information on detailed backup/restore architecture and when one should go for a particular kind of backup.

Replication is the process of copying/moving data between databases on the same or different servers. SQL Server supports the following types of replication scenarios:

• Snapshot replication
• Transactional replication (with immediate updating subscribers, with queued updating subscribers)
• Merge replication

See SQL Server books online for indepth coverage on replication. Be prepared to explain how different replication agents function, what are the main system tables used in replication etc.

The global variable @@Version stores the build number of the sqlservr.exe, which is used to determine the service pack installed. To know more about this process visit SQL Server service packs and versions.

Cursors allow row-by-row prcessing of the resultsets.

Types of cursors: Static, Dynamic, Forward-only, Keyset-driven. See books online for more information.

Disadvantages of cursors: Each time you fetch a row from the cursor, it results in a network roundtrip, where as a normal SELECT query makes only one rowundtrip, however large the resultset is. Cursors are also costly because they require more resources and temporary storage (results in more IO operations). Furthere, there are restrictions on the SELECT statements that can be used with some types of cursors.

Most of the times, set based operations can be used instead of cursors. Here is an example:

If you have to give a flat hike to your employees using the following criteria:

Salary between 30000 and 40000 -- 5000 hike
Salary between 40000 and 55000 -- 7000 hike
Salary between 55000 and 65000 -- 9000 hike

In this situation many developers tend to use a cursor, determine each employee's salary and update his salary according to the above formula. But the same can be achieved by multiple update statements or can be combined in a single UPDATE statement as shown below:

UPDATE tbl_emp SET salary =
CASE WHEN salary BETWEEN 30000 AND 40000 THEN salary + 5000
WHEN salary BETWEEN 40000 AND 55000 THEN salary + 7000
WHEN salary BETWEEN 55000 AND 65000 THEN salary + 10000
END

Another situation in which developers tend to use cursors: You need to call a stored procedure when a column in a particular row meets certain condition. You don't have to use cursors for this. This can be achieved using WHILE loop, as long as there is a unique key to identify each row. For examples of using WHILE loop for row by row processing, check out the 'My code library' section of my site or search for WHILE.

Here's the basic syntax: (Also checkout SELECT in books online for advanced syntax).

SELECT select_list
[INTO new_table_]
FROM table_source
[WHERE search_condition]
[GROUP BY group_by_expression]
[HAVING search_condition]
[ORDER BY order_expression [ASC | DESC] ]

Joins are used in queries to explain how different tables are related. Joins also let you select data from a table depending upon data from another table.

Types of joins: INNER JOINs, OUTER JOINs, CROSS JOINs. OUTER JOINs are further classified as LEFT OUTER JOINS, RIGHT OUTER JOINS and FULL OUTER JOINS.

For more information see pages from books online titled: "Join Fundamentals" and "Using Joins".

Yes, very much. Check out BEGIN TRAN, COMMIT, ROLLBACK, SAVE TRAN and @@TRANCOUNT

An extended stored procedure is a function within a DLL (written in a programming language like C, C++ using Open Data Services (ODS) API) that can be called from T-SQL, just the way we call normal stored procedures using the EXEC statement. See books online to learn how to create extended stored procedures and how to add them to SQL Server.

Yes, you can instantiate a COM (written in languages like VB, VC++) object from T-SQL by using sp_OACreate stored procedure. Also see books online for sp_OAMethod, sp_OAGetProperty, sp_OASetProperty, sp_OADestroy. For an example of creating a COM object in VB and calling it from T-SQL, 

USER_ID(). Also check out other system functions like USER_NAME(), SYSTEM_USER, SESSION_USER, CURRENT_USER, USER, SUSER_SID(), HOST_NAME().

Triggers are special kind of stored procedures that get executed automatically when an INSERT, UPDATE or DELETE operation takes place on a table. 

In SQL Server 6.5 you could define only 3 triggers per table, one for INSERT, one for UPDATE and one for DELETE. From SQL Server 7.0 onwards, this restriction is gone, and you could create multiple triggers per each action. But in 7.0 there's no way to control the order in which the triggers fire. In SQL Server 2000 you could specify which trigger fires first or fires last using sp_settriggerorder

Triggers can't be invoked on demand. They get triggered only when an associated action (INSERT, UPDATE, DELETE) happens on the table on which they are defined.

Triggers are generally used to implement business rules, auditing. Triggers can also be used to extend the referential integrity checks, but wherever possible, use constraints for this purpose, instead of triggers, as constraints are much faster.

Till SQL Server 7.0, triggers fire only after the data modification operation happens. So in a way, they are called post triggers. But in SQL Server 2000 you could create pre triggers also. Search SQL Server 2000 books online for INSTEAD OF triggers. 

Also check out books online for 'inserted table', 'deleted table' and COLUMNS_UPDATED()

Instantiating COM objects is a time consuming process and since you are doing it from within a trigger, it slows down the data insertion process. Same is the case with sending emails from triggers. This scenario can be better implemented by logging all the necessary data into a separate table, and have a job which periodically checks this table and does the needful.

Self join is just like any other join, except that two instances of the same table will be joined in the query. Here is an example: Employees table which contains rows for normal employees as well as managers. So, to find out the managers of all the employees, you need a self join.

CREATE TABLE emp 
(
empid int,
mgrid int,
empname char(10)
)

INSERT emp SELECT 1,2,'Vyas'
INSERT emp SELECT 2,3,'Mohan'
INSERT emp SELECT 3,NULL,'Shobha'
INSERT emp SELECT 4,2,'Shridhar'
INSERT emp SELECT 5,2,'Sourabh'

SELECT t1.empname [Employee], t2.empname [Manager]
FROM emp t1, emp t2
WHERE t1.mgrid = t2.empid

Here's an advanced query using a LEFT OUTER JOIN that even returns the employees without managers (super bosses)

SELECT t1.empname [Employee], COALESCE(t2.empname, 'No manager') [Manager]
FROM emp t1
LEFT OUTER JOIN
emp t2
ON
t1.mgrid = t2.empid 

• 1.1) Who helped you put this list together?
• 1.2) When someone refers to 'rn(1)' or 'ctime(3)', what does the number in parentheses mean?
• 1.3) What does {some strange unix command name} stand for?
• 1.4) How does the gateway between "comp.unix.questions" and the "info-unix" mailing list work?
• 1.5) What are some useful Unix or C books?
• 1.6) What happened to the pronunciation list that used to be part of this document