Oracle is a Relational Database Management System (RDBMS) which is used widely for business applications.
2. What is SGA?
The System Global Area (SGA) is a shared memory region allocated by ORACLE that contains data and control information for one ORACLE instance.
3. What is the function of Checkpoint (CKPT)?
The Checkpoint (CKPT) process is responsible for signaling DBWR at checkpoints and updating all the data files and control files of the database.
The CKPT is also useful to get the point in time from where to begin the recovery in case of failure.
Which background process is responsible for writing the dirty buffers from the write list to the data files during a checkpoint?
The DBWn is usually responsible for this.
What are the components of SGA?
The components of the SGA are Database buffers, Redo Log Buffer and the Shared Pool.
4. What constitute an ORACLE Instance?
SGA and ORACLE background processes together constitute an ORACLE instance.
What do Database Buffers contain?
Database Buffers store the most recently used blocks of database data. They can also contain modified data that has not yet been permanently written to disk.
5. What do Redo Log Buffers contain?
Redo Log Buffers store redo entries or a log of changes made to the database.
6. What is Shared Pool?
Shared pool is composed of two parts; Library Cache and Data Dictionary Cache.
The Library Cache contains the shared SQL areas, private SQL areas, PL/SQL procedures and packages, and control structures such as locks and Library Cache handles. The shared SQL area contains the parse tree and execution plan; whereas the private SQL area contains values for bind variables and runtime buffers. The data dictionary cache holds most recently used database dictionary information.
7. What is the default undo management mode in ORACLE?
The default undo management mode is manual.
8. How can you dynamically size the SGA?
You can do this using the Alter System command.
9. What is the Multiple Block size?
We can assign different block sizes for each table space. This is called the Multiple Block size.
10. Where are the compiled functions and procedures stored in memory?
These are stored in the Library Cache.
11. What is SQL*PLUS?
It is a browser-based interface to communicate with the database.
12. What are the advantages of creating clusters in ORACLE?
It improves the efficiency of join queries and they are storage efficient.
13. What are Bind Variables?
A bind variable is a variable that you declare in a host environment. Bind variables can be used to pass run-time values, either number or character, into or out of one or more PL/SQL programs. The PL/SQL programs use bind variables as they would use any other variable. You can reference variables declared in the host or calling environment in PL/SQL statements, unless the statement is in a procedure, function, or package. This includes host language variables declared in precompiler programs, screen fields in Oracle Developer Forms applications, and iSQL*Plus bind variables.
14. How to create Bind Variables?
To declare a bind variable in the iSQL*Plus environment, use the command VARIABLE. For example, you declare a variable of type NUMBER and VARCHAR2 as follows:
VARIABLE return_code NUMBER
VARIABLE return_msg VARCHAR2(30)
Both SQL and iSQL*Plus can reference the bind variable, and iSQL*Plus can display its value through the iSQL*Plus PRINT command.
15. Explain few programming guidelines for PL/SQL ?
To produce clear code and reduce maintenance when developing a PL/SQL block follow the below listed guidelines
- Documenting code with comments
- Developing a case convention for the code
- Developing naming conventions for identifiers and other objects
- Enhancing readability by indenting
16. What are the advantages of using cursors with FOR LOOPS?
A cursor FOR loop is a shortcut because of the following reasons
- the cursor is opened automatically when the for loop is encountered for the first time and fetches the first row
- rows are fetched once for each iteration in the loop
- The loop itself is terminated automatically at the end of the iteration where the last row is fetched.
17. What is the use of NO WAIT option with SELECT…. FOR UPDATE clause?
The optional NOWAIT keyword tells Oracle not to wait if requested rows have been locked by another user. Control is immediately returned to your program so that it can do other work before trying again to acquire the lock. If you omit the NOWAIT keyword , Oracle waits until the rows are available.
18. Can we use raise system defined exceptions explicitly by issuing the RAISE statement?
Yes, you can. For example : RAISE NO_DATA_FOUND
19. Can we handle the exception raised by RAISE_APPLICATION_ERROR?
Yes. For example, you can write “WHEN OTHERS” exception handler, and handler for this.
20. Can we assign default values to all modes of parameters in a subprogram?
You can assign default values only to parameters of the IN mode. OUT and IN OUT parameters are not permitted to have default values.
21. How Procedures are different from Functions?
You create a procedure to store a series of actions for later execution. A procedure can contain zero or more parameters that can be transferred to and from the calling environment, but a procedure does not have to return a value.
You create a function when you want to compute a value, which must be returned to the calling environment. A function can contain zero or more parameters that are transferred from the calling environment. Functions should return only a single value, and the value is returned through a RETURN statement. Functions used in SQL statements cannot have OUT or IN OUT mode parameters.
22. What is the use of SHOW ERRORS command?
SHOW ERRORS command is used at the SQL prompt to obtain compilation errors for the last object you compiled.
You can also use the command with a specific program unit. The syntax is as follows:
SHOW ERRORS [{FUNCTION|PROCEDURE|PACKAGE|PACKAGE BODY|TRIGGER|VIEW} [schema.]name]
Example : SHOW ERRORS PROCEDURE p1
Using the SHOW ERRORS command, you can view only the compilation errors that are generated by the latest statement that is used to create a subprogram. The USER_ERRORS data dictionary view stores all the compilation errors generated previously while creating subprograms.
23. How to drop one member of a package?
You cannot drop members of a package using DROP command. When you drop the package, all the members of the package are automatically dropped. To drop or add any members of the package, rewrite the whole package again.
24. What will happen to the dependent constructs of a package ,if we change the package specification?
Changes to the package body do not require recompilation of dependent constructs, whereas changes to the package specification require recompilation of every stored subprogram that references the package. To reduce the need for recompiling when code is changed, place as few constructs as possible in a package specification.
25. Explain the firing sequence for a trigger on a table.
The sequence is as below :
a. Before Statement Trigger
b. Before Row Trigger
c. After row trigger
d. After statement Trigger
26. Can we write INSTEAD OF triggers on tables?
No, it is written only on views
27. What will happen to triggers when the table on which the trigger is written?
All triggers on a table are automatically dropped when the table is dropped.
]]>
This FAQ has been taken from http://www.intranetjournal.com/faq/js-faq.shtml with the permission of the editor.
For more details visit Intranet Journal at
http://idm.internet.com/index.html
http://www.intranetjournal.com/faq/js-faq.shtml
1. General
2. What versions of the language does this FAQ cover?
5. Can I mirror or reprint this FAQ?
2. JavaScript Documentation
1. Where can I find online documentation for JavaScript?
2. Where is the official bug list for JavaScript?
3. Read any good JavaScript books lately?
3. First Principles
1. What are the language’s basic entities?
2. How does JavaScript model the world? (Nifty Object Map.)
3. What are JavaScript event handlers?
4. How is JavaScript syntax like C / C++?
4. How do I …
1. … embed JavaScript in a web page?
2. … use ‘var’ to make a variable name local?
3. … use quotation marks when scripting?
6. … script a calendar on the fly?
7. … access objects and scripts in windows opened with window.open()?
8. … use JavaScript to password-protect my Web site?
9. … write browser-independent scripts?
10. … match text patterns like I can in Perl?
11. … prevent others from seeing/copying my scripts?
12. … detect whether JavaScript support has been disabled?
5. Troubleshooting
2. Where can scripts go wrong?
3. What are the most common scripting mistakes?
6. Portability
6. Programming Tools
1. What tools are available for developing JavaScript pages?
2. Borland IntraBuilderTM
3. Netscape Visual JavaScript 1.0
2. Are there any debugging tools for JavaScript?
JavaScript is a platform-independent, event-driven, interpreted programming language developed by Netscape Communications Corp. and Sun Microsystems. Originally called LiveScript (and still called LiveWireTM by Netscape in its compiled, server-side incarnation), JavaScript is affiliated with Sun’s object-oriented programming language JavaTM primarily as a marketing convenience. They interoperate well but are technically, functionally and behaviorally very different.
JavaScript is useful for adding interactivity to the World Wide Web because scripts can be embedded in HTML files (i.e., web pages) simply by enclosing code in a <SCRIPT> </SCRIPT> tag pair. All modern browsers can interpret JavaScript — albeit with some irritating caveats. (More about them below.)
In practice, JavaScript is a fairly universal extension to HTML that can enhance the user experience through event handling and client-side execution, while extending a web developer’s control over the client’s browser. And that’s worth a FAQ.
This FAQ covers the language through JavaScript 1.2, the version deployed in Netscape Communicator 4.0x, plus some compatibility items with Jscript as implemented in Microsoft Internet Explorer 3.0x. The focus here is on client-side JavaScript.
Other browser-based scripting languages such as Microsoft VBScript. Server-side JavaScript and Netscape LiveWire Pro. Database connectivity. Known bugs. Netscape’s JSRef source libraries for embedding the JavaScript interpreter in third-party code.
The answers herein have been compiled from several sources. The largest contribution is from Danny Goodman’s JavaScript Mini-FAQ, updated periodically in the newsgroup comp.lang.javascript. Postings to that newsgroup are also a rich source of questions and answers. Items quoted or paraphrased from books on the subject are attributed in the text. Finally, we at IDM have added our own two cents worth.
Yes, with two restrictions. You must retain the previous paragraph (”Who wrote this FAQ?”), and you must cite Intranet Journal, giving the URL in print media and/or linking idm.internet.com in online media.
JavaScript Documentation
ECMAScript (ECMA-262) has since June 1997 been the official scripting standard for the Web. It is documented at:
http://www.ecma.ch/stand/ecma-262.htm
Current JavaScript docs (for Netscape) are available at:
home.netscape.com/eng/mozilla/3.0/handbook/javascript
Netscape’s JavaScript FAQ is at:
developer.netscape.com/support/faqs/champions/javascript.html
A zipped set of Netscape’s HTML documents is available at:
developer.netscape.com/library/documentation/jshtm.zip
Microsoft’s scripting language site is:
http://msdn.microsoft.com/scripting/
Netscape maintains a page of JavaScript Known Bugs in its online Navigator Release Notes. Unfortunately, according to guru Danny Goodman, “this list is not complete,” and we know of no definitive, well-maintained alternative.
Yes! As with computer books generally, texts on browser scripting are plentiful, but the number of good ones is surprisingly small. Nor are the best ones always the most visible. Intranet Journal’s favorites, for instance, include a pair of texts from British publisher Wrox Press Ltd.:
These programmer’s references are so good because they work from the browser object model up, recognizing fundamental differences between the Microsoft and Netscape approaches. As the titles suggest, they treat the gamut of client-side techniques for making web pages dynamic: JavaScript, VBScript, Layers and Style Sheets. They excel as references for each.
The Wrox books are written for a programming audience. Also in this category, but with different emphases, are the following:
Beginners and less technical webmasters may find one of the following sources a more suitable introduction to scripting.
A. As in most object-oriented, event-driven programming languages, there are four distinct entities in JavaScript:
fontcolor("red") sets the color of a text object to red. escape() and unescape(), JavaScript functions that perform ASCII to hex conversions. The existence of non-object-specific functions in JavaScript keeps it from being a truly object-oriented language like Java. if..else, while. JavaScript statements and syntax closely resemble those of the ‘C’ programming language. onClick is a typical event), or an entire web page (sample event: onLoad). The code that specifies what the object should do in response to an event is a special type of method called an event handler. A. This question goes to the heart of any OOPS [Object-Oriented Programming System]. The abbreviated answer given here — lengthy as it is — omits important differences between the Netscape and Microsoft browser object models, and between various versions of JavaScript. For a more accurate discussion refer to one of the programmer’s references cited elsewhere in this FAQ.
A. Among other things, event handlers are the subject of part II of Intranet Journal’s 3-part tutorial, JavaScript 101, by Reaz Hoque. That’s a good starting place. Also refer to the following diagram from Wrox Press Ltd., which puts browser events and the code that handles them in context.
A. The languages have enough in common to make learning one easy if you know the other. By the same token, the differences are subtle enough to trip up those proficient in both. Here’s a short list comparing C and JavaScript:
a ? b : c). Finally, JavaScript’s statements are a strict subset of C++’s, offering a smaller selection of identical looping and conditional constructs.
How do I …
Tim Ritchey offers a number of useful style guidelines in his book Programming JavaScript for NetscapeTM 2.0. Here’s how he writes JavaScript:
<SCRIPT LANGUAGE="JavaScript">
<!-- hide script from older browsers
[insert your code here]
// end script hiding -->
</SCRIPT>
Ritchey also points out that JavaScript accepts the C-language comment delimiters /* comment */, useful for multi-line comments.
By default all variables in JavaScript are global, meaning they retain their values everywhere in a scripted web page. To make a variable local to a block (such as a function), declare it with the keyword var. Here’s a n example:
// here 'i' is a global counter variable that could, if reused
// elsewhere in this script, create hard-to-find errors
for( i=1; i<=N; i++ ) {
[code to iterate]
}
// to ensure that 'i' exists only in the scope of this
// counter, use var:
for( var i=1; i<=N; i++ ) {
[ ... ]
}
Limiting a variable's scope is especially valuable when cutting-and-pasting an existing script, not necessarily written by you, into a new web page. If you use local variables in your functions, you needn't worry about stepping on variables in t he reused code.
There are two types of quote mark in JavaScript, the single-quote (') and double-quote ("). Either can be used to delimit a string literal, or sequence of characters. For example:
myDblQString = "This string is surrounded by double-quote marks.";
mySngQString = 'This string is surrounded by single-quote marks.';
However, since HTML itself makes extensive use of double-quotes within tags, it's a good idea to use single-quotes to set off strings in your scripts. This is particularly useful when your code contains quoted elements, as follows:
onClick = "alert( 'Are you sure?' )";
Strings containing apostrophes, which are identical to single-quotes, require you to use the backslash character (\) to escape the apostrophes, as shown below:
myEscString = 'John didn\'t like Mary\'s hat.';
Quoted strings can be combined with other strings, whether literals or variables:
errMsg = "Passwords are case-sensitive.";
message = "Error: " + errMsg;
// assigns 'Error: Passwords are case-sensitive.' to message
The most reliable way is to use straight HTML via a Submit style button. Set the ACTION of the <FORM> to a mailto: URL and the ENCTYPE attribute to "text/plain". For security reasons, the form.submit() method does not submit a form whose ACT ION is a mailto: URL.
Microsoft Internet Explorer 3.0x does not e-mail forms directly, though it can launch an e-mail client such as Eudora Pro or Outlook Express. These in turn convey identifying info to the recipient, offering a measure of security.
At best, a client-side script can show the visitor how many she has been to the site (storing the count in a local cookie). A count of total hits to the server requires a server-side program.
If you view the source of Intranet Journal's Events page, you'll have your answer in freely distributable form. Features of this homegrown implementation include:
object-oriented, with perpetual calendar class
reusable isLeapYear() function
highlights current day
Y2000 compliant
easily invoked from page <BODY> via forms or embedded script commands. Here's a typical invocation:
<SCRIPT LANGUAGE="JavaScript">
<!--
// insert on-the-fly day calendar
makeCal(9, 1997); // September 1997
// -->
</SCRIPT>
To use the code, you'll need to change the part of the getHTML() method demarked "page specific stuff." The code is unsupported and not warranted for any particular use.
First, be sure to assign an 'opener' property to the new window if you are using a version of JS that doesn't do it automatically (Navigator 3.0x and MSIE 3.0x do it automatically). The following script should be a part of every new window creation:
var newWind = window.open("xxx","xxx","xxx") // u fill in blanks
if (newWind.opener == null) { // for Nav 2.0x
newWind.opener = self // this creates and sets a new property
}
To access items in the new window from the original window, the 'newWind' variable must not be damaged (by unloading), because it contains the only reference to the other window you can use (the name you assign as the second parameter of open() is not valid for scripted window references; only for TARGET attributes).< /P>
To access a form element property in the new window, use:
newWind.document.formName.elementName.property
From the new window, the 'opener' property is a reference to the original window (or frame, if the window.open() call was made from a frame). To reference a form element in the original window:
opener.document.formName.elementName.property
Finally, if the new window was opened from one frame in the main browser window, and a script in the new window needs access to another frame in the main browser window, use:
opener.parent.otherFrameName.document.formName
There are a number of schemes, but be warned that most fail to deflect the knowledgeable script programmer because no matter how you encode the correct password (e.g., bit shifting), both the encoding algorithms and the result have to be in the script -- whose source code is easily accessible. If you're only interested in keeping out casual visitors, this method may suffice.
A more secure way is to set the password to be the name or pathname of the HTML file on your site that is the 'true' starting page. Set the location to the value entered into the field (unfortunately, you cannot extract the value property of a password object in Navigator 2.0x). Entry of a bogus password yields an 'invalid URL' error.
If the protected pages need additional security (e.g., an infidel has managed to get the complete URL), you might also consider setting a temporary cookie on the password page; then test for the existence of that cookie upon entry to every protected page, and throw the infidel back to the password page.
Strictly speaking, you can’t. Many browsers don't support Javascript at all. We’ve come to think of the Web as a franchise fought over by Netscape and Microsoft, but there are still people who browse with Lynx, NCSA Mosaic, UdiWWW, Cello – well, maybe not Cello. ;^)
Speaking informally, there are two ways to write more portable code. One is to use only least-common-denominator features supported by all versions of Navigator and MSIE. We’re talking JavaScript 1.0, introduced with Netscape 2.0 and IE 3.0. This approach has a couple of drawbacks:
Your other option is browser-detection. By running a script at load time that identifies the browser it’s executing in, you can branch conditionally to appropriately optimized code. This is good stuff, though it won’t work for all browsers and requires you to add a lot of gobbledy-gook to your web pages.
Here’s a typical browser-detection routine you can customize:
<SCRIPT language="JavaScript">
<!--
function checkBrowser(NSvers,NSpass,NSnoPass,IEvers,IEpass,
IEnoPass,OBpass,URL,altURL) {
var newURL = '', version = parseFloat(navigator.appVersion);
if (navigator.appName.indexOf('Netscape') != -1) {
if (version >= NSvers)
{if (NSpass>0) newURL = (NSpass==1)?URL:altURL;}
else
{if (NSnoPass>0) newURL = (NSnoPass==1)?URL:altURL;}
} else if (navigator.appName.indexOf('Microsoft') != -1) {
if (version >= IEvers)
{if (IEpass>0) newURL = (IEpass==1)?URL:altURL;}
else
{if (IEnoPass>0) newURL = (IEnoPass==1)?URL:altURL;}
} else if (OBpass>0) {newURL = (OBpass==1)?URL:altURL};
if (newURL) {
window.location = unescape(newURL);
document.returnValue = false;
}
}
//-->
</SCRIPT>
This code, which should appear in the HEAD section of a web page, jumps to another page if the visitor is using a browser earlier than version 4.0.
The short answer is, "By forgetting about JavaScript and coding server-side CGI scripts in Perl."
A longer, browser-dependent answer: read Angus Young's article, "String matching and replacing in JavaScript 1.2."
You can't. There is no way to produce an HTML document that can be rendered in a browser but whose source cannot be examined in its entirety, scripts included. And since web browsers have functions like "View Source" and "Save As HTML," copying is a cut-and-paste operation.
Putting a copyright notice at the head of your code affords some legal protection.
Microsoft has introduced a technique called script encoding that garbles HTML, ASP, VBS, and JScript source code so that it is unreadable by a casual user. (The lightweight encryption used won't stop determined hackers.) The technique requires Microsoft's version 5.0 Script Engine; it won't execute in Netscape Navigator or earlier MSIE versions.
Common sense says that if you're going to detect if JavaScript is disabled, you'd better do it in something besides JavaScript! Check instead to see if scripting is enabled.
You might, for instance, use something like document.location = 'java_page.html' to redirect the browser to a new, script-laden page. Failure to redirect implies that JavaScript is unavailable, in which case you can either resort to CGI routines or insert appropriate code between the <NOSCRIPT> tags. (NOTE: NOSCRIPT is only available in Netscape Navigator 3.0 and up.)
Troubleshooting
Quite a bit. Primarily for security reasons, client-side scripting languages like JavaScript cannot:
Many of these items are possible in Netscape Communicator 4.0, which features the enhanced (and proprietary) version 1.2 of JavaScript. Moreover, those items perceived to be security risks (e.g., access browser settings) require "signed JavaScript."
MSIE JScript v2 (more below) can read/write local files via ActiveX - a source of that architecture's widely publicized security pitfalls.
There are three distinct areas where errors can occur in any computer program:
Load-time errors
Your script is part of a web page. When someone browses (i.e., requests) that page, your server returns it over the network. On receiving it the requesting browser loads your page: HTML, JavaScript, and any other objects it contains.
Load-time errors are caught by the JavaScript interpreter. As the browser loads your script, it performs myriad checks for basic language problems -- usually syntax errors. If, for instance, you leave off the closing half of a pair of parentheses, the interpreter will tell you about it in the form of a load-time error. Why? Because a script can't run until it has loaded successfully.
By checking your scripts in two browsers -- Netscape Navigator 3.0 (or later) and Microsoft Internet Explorer 3.0 (or later) -- you leverage the language-checking abilities of JavaScript itself to detect load-time errors.
Run-time errors
If your script loads, it will run. It may perform exactly as you designed it to, or it may crash and burn. Like load-time errors, problems at run-time are detected and reported by the JavaScript interpreter. In effect, it says (very quietly): "I loaded that nice-looking script and now it's breaking the rules, corrupting memory and whatnot. I'd better tell somebody." Up pops an alert window to apprise you of the run-time error.
When a program is running it manipulates stored data, operating on values in memory as specified by program commands. Thus, whereas errors occur at load time chiefly due to bad syntax, run-time errors are often due to misuse of the language's commands.
For instance, you'll get a run-time error if at some point your script divides by zero (illegal in any language).
Logic errors
These are the bad guys, problems worthy of the epithet "bugs." Errors loading or running your script are caught by the machine; errors in the logic of you program can only be caught by you or your users -- in other words, humans. When your script runs without complaining but ends up doing the wrong thing, you've got a logic error.
The best way to verify your program logically is to stress it. You probably won't be able to exercise all the possible inputs, outputs, if-then statements and loops, but by hitting a few major ones, you gain confidence that any errors are at least well hidden. If and when these occur, of course, they may be equally hard to trace. But that's software for you.
In his excellent JavaScript Sourcebook, in a section that begins, "We're only human, after all, and making mistakes is part of our nature," Gordon McComb identifies eleven common JavaScript gaffs:
There is a long-standing bug in JavaScript concerning tables. To be safe, Do not place <SCRIPT> tags inside <TD> tags. Instead, start the <SCRIPT> tag before the <TD> tag, and document.write() the <TD> tag through the </TD> tag. If you're a belt-and-suspenders kind of guy, you can go a step further by using document.write() to create the entire table , interlacing script statements where needed.
JScript is available on the Macintosh starting with 3.0.1 (which is different from the Windows 3.01). I am still evaluating the Mac implementation, whose object model and other support for JavaScript does not necessarily jive with the Windows version (e.g., the Mac version supports the Image object for mouse rollovers). MSIE 3.0.1 runs on Mac 68K and PPC. Download it from: http://www.microsoft.com/msdownload/ieplatform/iemac.ht m
Most language features and objects that are new in Navigator 3.0 are not supported in MSIE 3.0, although several Navigator 3.0 items have been added to JScript version 2 (see below).
It does work, but not when you access the HTML file from your local hard disk, as you are probably doing during testing. Be aware, however, that MSIE limits you to one cookie name=value pair per domain, whereas Netscape allows up to 20 pairs per domain.
More than can fit here. Some items are compatible with Navigator 3.0+ (such as the Array object). Others are unique to MSIE, such as the Dictionary and TextStream objects (accessible via ActiveX). Additions are to the core language, not the document object model.
New functions let you determine the JScript version installed in IE, but JScript version 2 must be installed to get this data. If you use version 2 or 3.x language features, see www.microsoft.com/JScript for info about including a link button on your page to encourage visitors to upgrade their IE 3.0x to JScript version 2.
Installation of MSIE 3.02 does not guarantee JScript version 2. Search your disk for 'jscript.dll'. Get the file's properties, and click on the Version tab. The File version should begin with '2'. If not, download the latest version from Microsoft (installer is 442KB).
| UNSUPPORTED OBJECTS Image -- this means no onMouseOver swappable images in MSIE 3
Area -- no onMouseOvers Applet FileUpload *Array -- hard-wired (JS1.0) arrays OK; implemented in JScript v.2. MimeType Plugin |
What properties/methods/event handlers are unsupported in MSIE?
| UNSUPPORTED PROPERTIES/METHODS/EVENT HANDLERS OF SUPPORTED OBJECTS Window onerror closed blur() focus() scroll() onBlur= onFocus= Location reload() replace() Document applets[] domain embeds[] images[] URL Link onMouseOut=
Form reset() onReset= All Form Elements type
Navigator mimeTypes[] plugins[] javaEnabled() String prototype split() One more item: the |
Mark Stone wrote the book on it:
http://www.kudonet.com/~markst/jscript/jsdiff.htm
Actually it was "turned over" to ECMA, the European Computing Machine Association. They appear to be go-slow, secretive types. It remains to be seen whether this is a serious standardization effort, or a marketing ruse by Netscape to match Microsoft's dubious "turning over" of ActiveX to the X/Open Group.
Programming Tools
A scripting development aid from NetObjects, Inc. In addition to JavaScript, ScriptBuilder facilitates code writing in VBScript, LotusScript and Microsoft ASP. Reviewed by IDM in June 1998.
IntraBuilder is a web application development tool from Inprise Corporation (formerly Borland International) that makes heavy use of JavaScript. Together with companion products C++Builder and JBuilder, IntraBuilder is part of the product line that implements Inprise's "Golden Gate" strategy for web-based client/server development.
Each product in this line targets three developer levels with Standard, Professional and Client/Server editions, corresponding respectively to low ($99), medium ($499) and high ($1999) price points. The increments buy enhanced database connectivity and features for managing team development.
IntraBuilder consists of two primary components:
IntraBuilder Designer, a visual RAD environment for JavaScript that creates Forms -- used for entering, displaying and manipulating data; and Reports -- used for displaying data in a list format that can include groupings and aggregate functions, such as totals or averages. Significantly for readers of this FAQ, IntraBuilder provides wizards that coach the developer through web page specification, then automatically generates standard JavaScript, including form elements and data validation routines.
IntraBuilder Server, which extends basic web server functionality to deliver data-driven pages. IntraBuilder Server uses three primary architectural components (diagrammed below): IntraBuilder Broker, IntraBuilder Agents, and the Borland Database Engine (BDE).
The IntraBuilder Broker automatically provides the communications layer between the IntraBuilder Agents and the Web server, the first layer of state management, and intelligent routing.
IntraBuilder Agents automatically parse forms and reports, dynamically generate HTML, participate in state management, and manage data access and formatting.
The Borland Database Engine provides the database connectivity for IntraBuilder, connecting to a wide range of servers using native APIs and ODBC.
IntraBuilder belongs to a large, maturing class of web-to-database application development tools, several of which are listed in Intranet Journal's Gateways to Data section. IntraBuilder is specifically treated in this JavaScript FAQ because of the central role JavaScript plays in its design.
"A visual tool for rapid crossware development," according to its maker. Netscape defines crossware as "on-demand software that runs across networks, operating systems, and platforms and easily extends to partners and customers."
IDM has experimented with Preview Release 3 of Visual JavaScript 1.0. Functionally impressive, the product strikes us primarily as a weapon in Netscape's anti-Microsoft agenda, for three reasons:
Lack of support for Microsoft technologies contrasts with Visual JavaScript's otherwise very impressive feature set, which lets developers:
For more information, visit Netscape's web site, or better yet, download a trial release of Visual JavaScript and take its measure yourself.
Netscape bundles a debugger with Visual JavaScript.
The Microsoft Script Debugger is a debugging environment that extends any Microsoft ActiveX Scripting host application (for example, Internet Explorer or Internet Information Server).
Other Sources
|
For more details visit Intranet Journal at
]]>1. What is a reentrant program? How will you make a program Reentrant?
A. A reentrant program, while being executed resides in the common virtual area so that one copy of it may be shared among all callers. Use RENT compiler option.
2. What is the difference between a 01 level and 77 level?
A. 01 level can have sublevels from 02 to 49. 77 cannot have sublevel.
3. What are the few advantages of VS COBOL II over OS/VS COBOL?
A. The working storage and linkage section limit has been increased. They are 128 megabytes as supposed to 1 megabytes in OS/VS COBOL. Introduction of ADDRESS special register.
31-bit addressing. In using COBOL on PC we have only flat files and the programs can access only limited storage, whereas in VS COBOL II on M/F the programs can access up to 16MB or 2GB depending on the addressing and can use VSAM files to make I/O operations faster.
4. What are the steps you go through while creating a COBOL program executable?
A. DB2 pre-compiler (if embedded SQL is used), CICS translator (if CICS program), Cobol compiler, Link editor. If DB2 program, create plan by binding the DBRMs.
5. What are the minimum requirements to compile a program without errors?
A. Identification Division.
Program-ID. Program-name.
A) Is compute w=u a valid statement?
Yes, it is. It is equivalent to move u to w.
B) In the above example, when will you prefer compute statement over the move statement?
When significant left-order digits would be lost in execution, the COMPUTE statement can detect the condition and allow you to handle it. The MOVE statement carries out the assignment with destructive truncation. Therefore, if the size error is needs to be detected, COMPUTE will be preferred over MOVE. The ON SIZE ERROR phrase of COMPUTE statement, compiler generates code to detect size-overflow.
6. What happens when the ON SIZE ERROR phrase is specified on a COMPUTE statement?
A. If the condition occurs, the code in the ON SIZE ERROR phrase is performed, and the content of the destination field remains unchanged. If the ON SIZE ERROR phrase is not specified, the assignment is carried out with truncation. There is no ON SIZE ERROR support for the MOVE statement.
7. How will you associate your files with external data sets where they physically reside?
A. Using SELECT clause, the files can be associated with external data sets. The SELECT clause is defined in the FILE-CONTROL paragraph of Input-Output Section that is coded Environment Division. The File structure is defined by FD entry under File-Section of Data Division for the OS.
8. How will you define your file to the operating system?
A. Associate the file with the external data set using SELECT clause of INPUT-OUTPUT SECTION. INPUT-OUTPUT SECTION appears inside the ENVIRONMENT DIVISION.
Define your file structure in the FILE SECTION of DATA DIVISION.
9. Explain the use of Declaratives in COBOL?
10. A statically bound subprogram is called twice. What happens to working-storage variables?
A. The working-storage section is allocated at the start of the run-unit and any data items with VALUE clauses are initialized to the appropriate value at the time. When the subprogram is called the second time, a working-storage items persist in their last used state. However, if the program is specified with INITIAL on the PROGRAM-ID, working-storage section is reinitialized each time the program is entered.
PROGRAM-ID. <Pgmname> is INITIAL PROGRAM. Other verbs used with PROGRAM-ID are RECURSIVE and COMMON.
11. When is COMMON attribute used?
A. COMMON attribute is used with nested COBOL programs. If it is not specified, other nested programs will not be able to access the program. PROGRAM-ID. Pgmname is COMMON PROGRAM.
12. In which division and section, the Special-names paragraph appears?
A. Environment division and Configuration Section.
13. What is the LOCAL-STORAGE SECTION?
A. Local-Storage is allocated each time the program is called and is de-allocated when the program returns via an EXIT PROGRAM, GOBACK, or STOP RUN. Any data items with a VALUE clauses are initialized to the appropriate value each time the program is called. The value in the data items is lost when the program returns. It is defined in the DATA DIVISION after WORKING-STORAGE SECTION
14. What does passing BY REFERENCE mean?
A. When the data is passed between programs, the subprogram refers to and processes the data items in the calling program’s storage, rather than working on a copy of the data. When
CALL . . . BY REFERENCE identifier. In this case, the caller and the called share the same memory.
15. What does passing BY CONTENT mean?
A. The calling program passes only the contents of the literal, or identifier. With a CALL . . . BY CONTENT, the called program cannot change the value of the literal or identifier in the calling program, even if it modifies the variable in which it received the literal or identifier.
16. What does passing BY VALUE mean?
A. The calling program or method is passing the value of the literal, or identifier, not a reference to the sending data item. The called program or invoked method can change the parameter in the called program or invoked method. However, because the subprogram or method has access only to a temporary copy of the sending data item, those changes do not affect the argument in the calling program. Use By value, If you want to pass data to C program. Parameters must be of certain data type.
17. What is the default, passing BY REFERENCE or passing BY CONTENT or passing BY VALUE?
A. Passing by reference (the caller and the called share the same memory).
18. Where do you define your data in a program if the data is passed to the program from a Caller program?
A. Linkage Section
19. Define the structure of a COBOL subroutine.
A. The PROCEDURE DIVISION header must have a using a phrase, if the data needs to be passed to the program. The operands of the USING phrase must be defined in the LINKAGE SECTION as 01-level or 77-level entries. No VALUE clause is allowed unless the data defined is a condition name.
If the program needs to be returned to the CALLER, use EXIT PROGRAM statement at the end of the program. GOBACK is an alternative, but is nonstandard.
20. What is difference between next sentence and continue
A. NEXT SENTENCE gives control to the verb following the next period. CONTINUE gives control to the next verb after the explicit scope terminator. (This is not one of COBOL II’s finer implementations). It’s safest to use CONTINUE rather than NEXT SENTENCE in COBOL II. CONTINUE is like a null statement (do nothing) , while NEXT SENTENCE transfers control to the next sentence (!!) (A sentence is terminated by a period). Check out by writing the following code example, one if sentence followed by 3 display statements: If 1 > 0 then next sentence end if display ‘line 1′ display ‘line 2′. display ‘line 3′. *** Note- there is a dot (.) only at the end of the last 2 statements, see the effect by replacing Next Sentence with Continue ***
21. What is the difference between Structured Cobol Programming and Object Oriented COBOL programming?
A. Structured programming is a Logical way of programming using which you divide the functionality’s into modules and code logically. OOP is a Natural way of programming in which you identify the objects, first then write functions and procedures around the objects. Sorry, this may not be an adequate answer, but they are two different programming paradigms, which is difficult to put in a sentence or two.
22. PIC S9(4)COMP IS USED INPSPITE OF COMP-3 WHICH OCCUPIES LESS SPACE.WHY?
A. S9(4) COMP uses only 2 bytes. 9(4) COMP-3 uses 3 bytes. 3 bytes are more than 2 bytes. Hence COMP is preferred over COMP-3 in this case.
23. How many number of bytes and digits are involved in S9(10) COMP?
24. Which picture clause will you use to define a hexadecimal item in a VALUE clause?
A. 01 ws-hexitem PIC X(2) value X’020C’.
01 ws-hex redefines PIC S9(3) comp-3.
25. How many numbers of decimal digits are possible, when the amount of storage allocated for a USAGE COMP item is a) half word b) full word c) double word?
A. 2 bytes (halfword) for 1-4 Digits 4 bytes (fullword) for 5-9
8 bytes (doubleword) for 10-18
26. What is a scope terminator? Give examples.
27. How many dimensions are allowed for a table?
A. 7
28. How many subscripts or indexes are allowed for an OCCURS clause?
A. 7
29. Why cannot Occurs be used in 01 level?
A. Because, Occurs clause is there to repeat fields with the same format, but not the records.
30. Can a REDEFINES clause be used along with an OCCURS clause?
A. Yes, if the REDEFINES clause is subordinate to OCCURS clause.
31. Can you specify PIC clause and a VALUE with an OCCURS clause? Will the following code compile without errors?
01 WS-TABLE.
03 WS-TABLE-EL OCCURS 5 TIMES PIC X(1) VALUE SPACES.
A. Yes, the code will compile without any errors.
32. What would be the output, when the following code is executed?
01 WS-TABLE.
03 WS-TABLE-EL OCCURS 5 TIMES PIC X(1) VALUE ‘AAAAA’.
A. It cannot be executed because the code will compile with error ‘ “VALUE” literal “‘AAAA’” exceeded the length specified in the “PICTURE” definition’.
33. 01 WS-TABLE.
03 WS-TABLE-EL OCCURS 5 TIMES PIC X(1) VALUE ‘A’.
03 WS-EX REDEFINES WS-TABLE-EL PIC X(5). What can you expect?
A. Compile error. Direct Redefinition of OCCURS clause is not allowed.
34. 01 WS-TABLE.
03 WS-TABLE-EL OCCURS 5 TIMES.
04 FILLER-X PIC X(1) VALUE ‘A’. 04 WS-EX REDEFINES FILLER-X PIC X(1).
What would be the output of DISPLAY WS-TABLE?
A. ‘AAAAA’. The code will compile and execute as Redefinition of an item subordinate to OCCURS clause.
35. Is this allowed?
01 WS-TABLE.
03 FILLER-X PIC X(5) VALUE ‘AAAAA’.
03 WS-EX REDEFINES FILLER-X.
04 WS-TABLE-EL OCCURS 5 TIMES PIC X(1).
A. Yes
35. Is this allowed?
01 WS-TABLE.
03 FILLER-X PIC X(5) VALUE ‘AAAAA’.
03 WS-EX REDEFINES FILLER-X OCCURS 5 TIMES PIC X(1).
A. Yes
36. Which SEARCH verb is equivalent to PERFORM…VARYING?
37. What would be the output, when the following code is executed?
01 WS-TABLE.
03 WS-TABLE-EL OCCURS 5 TIMES PIC X(1) VALUE ‘A’.
:::
DISPLAY WS-TABLE.
A. The output will display ‘AAAAA’
38. Can a SEARCH be applied to a table which does not have an INDEX defined?
A. No, the table must be indexed.
39. What are the different rules applicable to perform a serial SEARCH?
A. The SEARCH can be applied to only a table which has the OCCURS clause and INDEXED BY phrase,
Before the use of the SEARCH the index must have some initial value. To search from beginning, set the index value to 1. Use the SEARCH verb without ALL phrase
40. A table has two indexes defined. Which one will be used by the SEARCH verb?
A. The index named first will be used, by Search.
41. What are the different rules applicable to perform a binary SEARCH?
A. The table must be sorted in ascending or descending order before the beginning of the SEARCH. Use OCCURS clause with ASC/DESC KEY IS dataname1 option
The table must be indexed. There is no need to set the index value. Use SEARCH ALL verb
42. How does the binary search work?
A. First the table is split into two halves and in which half, the item need to be searched is determined. The half to which the desired item may belong is again divided into two halves and the previous procedure is followed. This continues until the item is found. SEARCH ALL is efficient for tables larger than 70 items.
43. What is the difference between a binary search and a sequential search? What are the pertinent COBOL commands?
A. In a binary search the table element key values must be in ascending or descending sequence. The table is ‘halved’ to search for equal to, greater than or less than conditions until the element is found. In a sequential search the table is searched from top to bottom, so (ironically) the elements do not have to be in a specific sequence. The binary search is much faster for larger tables, While sequential Search works well with smaller ones. SEARCH ALL is used for binary searches; SEARCH for sequential.
44. Explain the difference between an internal and an external sort. The pros & cons & internal sort syntax …
A. An external sort is not coded as a COBOL program; it is performed through JCL and PGM=SORT. One can use IBM utility SYNCSORT for external sort process. It is understandable without any code reference. An internal sort can use two different syntaxes: 1.) USING, GIVING sorts are comparable to external sorts with no extra file processing; 2) INPUT PROCEDURE, OUTPUT PROCEDURE sorts allow for data manipulation before and/or after the sort. Syntax:
45. Which is the default, TEST BEFORE or TEST AFTER for a PERFORM statement?
46. What is the difference between PERFORM … WITH TEST AFTER and PERFORM … WITH TEST BEFORE?
A. If TEST BEFORE is specified, the condition is tested at the beginning of each repeated execution of the specified PERFORM range. If TEST AFTER is specified, the condition is tested at the end of the each repeated execution of the PERFORM range. With TEST AFTER, the range is executed at least once.
47. How do you code an in-line PERFORM?
A. PERFORM … <UNTIL> … <statements> END-PERFORM.
48. In an EVALUTE statement is the order of the WHEN clauses significant?
49. What is the default value(s) for an INITIALIZE and what keyword allows for an override of the default.
A. INITIALIZE sets spaces to alphabetic and alphanumeric fields. Initialize sets Zeroes to numeric fields. FILLER, OCCURS DEPENDING ON items are left untouched. The REPLACING option can be used to override these defaults.
50. What is SET <condition-name> TO TRUE all about, anyway?
A. In COBOL II the 88 levels can be set rather than moving their associated values to the related data item. (Web note: This change is not one of COBOL II’s better specifications.)
51. What is LENGTH in COBOL II?
A. LENGTH acts like a special register to tell the length of a group or an elementary item.
52. What is the function of a delimiter in STRING?
A. A delimiter in STRING causes a sending field to be ended and another to be started.
53. What is the function of a delimiter in UNSTRING?
A. A delimiter when encountered in the sending field causes the current receiving field to be switched to the next one indicated.
54. How will you count the number of characters in a null-terminated string?
A. MOVE 0 TO char-count
INSPECT null-terminated-string TALLYING char-count FOR CHARACTERS BEFORE X”00″
55. Which statement will you use to move non-null characters from a null-terminated String?
A. UNSTRING null-terminated-string DELIMITED BY X”00″ INTO target-area
COUNT IN char-count. (There are other methods, such as 1) using PERFORM 2) using SEARCH 3) using INSPECT and MOVE etc…)
56. 77 COUNTR PIC 9 VALUE ZERO.
01 DATA-2 PIC X(11). . .
INSPECT DATA-2
TALLYING COUNTR FOR LEADING “0″
REPLACING FIRST “A” BY “2″ AFTER INITIAL “C”
If DATA-2 is 0000ALABAMA, what will DATA-2 and COUNTER be after the execution of INSPECT verb?
A. Counter=4. Data-2 will not change as the Initial 'C' is not found.
57. 01 DATA-4 PIC X(11).
:::
INSPECT DATA-4 CONVERTING
“abcdefghijklmnopqrstuvwxyz” TO “ABCDEFGHIJKLMNOPQRSTUVWXYZ”
AFTER INITIAL “/” BEFORE INITIAL”?”
What will the contents of DATA-4 be after the conversion statement is performed, if before conversion
a) DATA-4 = a/five/?six b) DATA-4 = r/Rexx/RRRr c) DATA-4 = zfour?inspe
A. a) a/FIVE/?six b) r/REXX/RRRR c) zfour?inspe (no change at all)
58. What kind of error is trapped by ON SIZE ERROR option?
A. Fixed-point overflow. Zero raised to the zero power.
Division by 0. Zero raised to a negative number.
A negative number raised to a fractional power.
59. What is the point of the REPLACING option of a copy statement?
A. REPLACING allows for the same copy to be used more than once in the same code by changing the replace value. COPY xxx REPLACING <psuedotext1> BY <psuedotext2>.
60. When is a scope terminator mandatory?
A. Scope terminators are mandatory for in-line PERFORMS and EVALUATE statements. For readability, it’s recommended coding practice to always make scope terminators explicit.
61. Can you use REDEFINES clause in the FILE SECTION?
A. No
62. How will you define your record descriptions in the FILE SECTION if you want to use three different record descriptions for the same file?
A. FD filename
DATA RECORDS ARE rd01, rd02, rd03.
01 rd01 PIC X(n).
01 rd02 PIC X(n).
01 rd03 PIC X(n).
63. When will you open a file in the EXTEND mode?
A. When an existing file should be appended by adding new records at its end. EXTEND mode opens the file for output, but the file is positioned following the last record on the existing file.
64. What does a CLOSE WITH LOCK statement do?
A. The statement closes an opened file and it prevents the file from further being opened by the same program.
65. Which mode of opening is required when REWRITE is used?
A. I-O mode
66. Why is it necessary that the file be opened in I-O mode for REWRITE?
A. Before the REWRITE is performed, the record must be read from the file. Hence REWRITE includes an input operation and an output operation. Therefore, the file must be opened in I-O mode.
67. Which clause can be used instead of checking for FILE STATUS = 10?
A. FILE STATUS 10 is the end of file condition. Hence AT END clause can be used.
68. What is the format of a simple SORT verb? What kinds of files can be sorted using SORT?
A. SORT workfile ON ASC/DESC KEY key1, ASC/DESC KEY key2 …
USING inputfile GIVING outputfile
Only sequential files can be sorted in this way.
69. What are the different rules of SORT that needs to be considered?
70. What are INPUT PROCEDURE and OUTPUT PROCEDURE?
A. Sometimes, it is necessary that the records must be edited before or after the sorting. In such cases,
SORT workfile ASC/DESC KEY key1, …
INPUT PROCEDURE IS ipproc
OUTPUT PROCEDURE is outproc
Is used. In the INPUT PROCEDURE the input file is opened, records are read and edited and then are released to the sorting operation. Finally the file is closed. RELEASE sortrecname FROM inp-rec.
In the OUTPUT PROCEDURE, output file is opened, the sorted record is returned to the Output record area and then the record is written. Finally the file is closed. RETURN workfile RECORD into out-rec.
71. What is the format of a simple MERGE verb? Can INPUT PROCEDURE and OUTPUT PROCEDURE can be specified for MERGE verb?
A. MERGE work file ON ASC/DESC KEY key1…
USING inputfile1, inputfile2…
GIVING outputfile
INPUT PROCEDURE cannot be specified. Only OUTPUT PROCEDURE can be specified
72. How will you position an indexed file at a specific point so that the subsequent sequential operations on the file can start from this point?
A. Use START
START filename KEY IS EQ/GT/LT.. dataname
INVALID KEY …
73. What are the access mode requirements of START statement?
A. Access mode must be SEQUENTIAL or DYNAMIC
74. What are the opening mode requirements of START statement?
75.What is the LINKAGE SECTION used for?
A. The linkage section is used to pass data from one program to another program or to pass data from a PROC to a program. It is part of a called program that ‘links’ or maps to data items in the calling program’s working storage. It is the part of the called program where these share items are defined.
76. If you were passing a table via linkage, which is preferable – a subscript or an index?
A. Wake up – you haven’t been paying attention! It’s not possible to pass an index via linkage. The index is not part of the calling programs working storage. Indexing uses binary displacement. Subscripts use the value of the occurrence.
77. What is the difference between a subscript and an index in a table definition?
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 Cobol statements.
78. What is an in line PERFORM? When would you use it? Anything else to say about it?
When the body of the Perform will not be used in other paragraphs. If the body of the Perform is a generic type of code (used from various other places in the program), it would be better to put the code in a separate para and use PERFORM paraname rather than in-line perform.
79. What is the use of EVALUATE statement? How do you come out of an EVALUATE statement?
A. 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, There is no need of any extra code. EVALUATE can be used in place of the nested IF THEN ELSE statements.
80. What are the different forms of EVALUATE statement?
A. EVALUATE EVALUATE SQLCODE ALSO FILE-STATUS
WHEN A=B AND C=D WHEN 100 ALSO ‘00′
Imperative stmt imperative stmt
WHEN (D+X)/Y = 4 WHEN -305 ALSO ‘32′
imperative stmt imperative stmt
WHEN OTHER WHEN OTHER
imperative stmt imperative stmt
END-EVALUATE END-EVALUATE
EVALUATE SQLCODE ALSO A=B EVALUATE SQLCODE ALSO TRUE
WHEN 100 ALSO TRUE WHEN 100 ALSO A=B
imperative stmt imperative stmt
WHEN -305 ALSO FALSE WHEN -305 ALSO (A/C=4)
imperative stmt imperative stmt
END-EVALUATE END-EVALUATE
81. Can you use the INSPECT (with TALLYING option) Cobol verb in a CICS COBOL program?
A. Yes, under COBOL II environment, but not OS/VS COBOL.
82. What is an explicit scope terminator?
83. What is the significance of ‘above the line’ and ‘below the line’?
A. Before IBM introduced MVS/XA architecture in the 1980’s a program’s virtual storage was limited to 16 megs. Programs compiled with a 24-bit mode can only address 16 MB of space, as though they were kept under an imaginary storage line. With COBOL II a program compiled with a 31 bit mode can be ‘above the 16 Mb line. (This ‘below the line’, ‘above the line’ imagery confuses most mainframe programmers, who tend to be a literal minded group.)
84. What was removed from COBOL in the COBOL II implementation?
A. Partial list: REMARKS, NOMINAL KEY, PAGE-COUNTER, CURRENT-DAY, TIME-OF-DAY, STATE, FLOW, COUNT, EXAMINE, EXHIBIT, READY TRACE and RESET TRACE.
85. Explain call by context by comparing it to other calls.
A. The parameters passed in a call by context are protected from modification by the called program. In a normal call they are able to be modified.
86. What is the difference between comp and comp-3 usage? Explain other COBOL usages.
87. I understand the possible causes for S0C1 & S0C4 abends, but what are they really?
A. A S0C1 occurs if the CPU attempts to execute binary code that isn’t a valid machine instruction; e.g. if you attempt to execute data. A S0C4 is a memory protection violation. This occurs if a program attempts to access storage beyond the areas assigned to it.
88. What happens when we move a comp-3 field to an edited ( say z(9).zz-)
A. The editing characters are to be used with data items with usage clause as display, which is the default. When you try displaying a data item with usage as computational it does not give the desired display format because the data item is stored as packed decimal. So if u want this particular data item to be edited u have to move it into a data item whose usage is display and then have that particular data item edited in the format desired.
89. What are the causes for S0C1, S0C4, S0C5, S0C7, S0CB abends
S0C4 may be due to 1.Missing Select statement(during compile) 2.Bad Subscript/index 3.Protection Exception 4.Missing parameters on called subprogram 5.Read/Write to unopened file 6.Move data from/to unopened file.
S0C5 May be due to 1.Bad Subscript/index 2.Close an unopen dataset 3.Bad exit from a perform 4.Access to I/O area(FD) before read.
S0C7 may be due to 1.Numeric operation on non-numeric data 2.Un-initialize working-storage 3.Coding past the maximum allowed sub script. S0CB may be due to 1.Division by Zero
90. What will happen if you code GO BACK instead of STOP RUN in a stand-alone COBOL program i.e. a program which is not calling any other program.
91. What is the difference between an External and a Global Variable ’s?
A. Global variables are accessible only to the batch program whereas external variables can be referenced from any batch program residing in the same system library.
92. WHAT IS REPORT-ITEM?
A. A REPORT-item is a field to be printed that contains EDIT SYMBOLS
93. You are writing report program with 4 levels of totals:city,state,region and country. The codes being used can be the same over the different levels, meaning a city code of 01 can be in any number of states, and the same applies to state and region code show. Do you do your checking for breaks and how do you do add to each level?
94. What is PSB & ACB?
A. PSB : Program specification block. Inform about how a specific program is to be access one or more IMS DB. It consists of PCB(Prg Communication Block). Information to which segment in DB can be accessed, what the program is allowed to do with those segment and how the DB is to be accessed. ACB : Access Control Blocks are generated by IMS as an expansion of information contained in the PSB in order to speed up the access to the applicable DBD’s.
95. What’s a LDS(Linear Data Set) and what’s it used for ?
A. LDS is a VSAM dataset in name only. It has unstructured 4k (4096 bytes) fixed size CIs which do not contain control fields and therefore from VSAM’s standpoint they do not contain any logical records. There is no freespace, and no access from Cobol. Can be accessed by DB2 and IMS fast path datasets. LDS is essentially a table of data maintained on disk. The ‘table entries’ must be created via a user program and can only be logically accessed via a user program. When passed, the entire LDS must be mapped into storage, then data is accessed via base and displacement type processing.
96. What is the Importance of GLOBAL clause According to new standards of COBOL
A. When any data name, file-name , Record-name, condition name or Index defined in an Including Program can be referenced by a directly or indirectly in an included program, Provided the said name has been declared to be a global name by GLOBAL Format of Global Clause is01 data-1 PIC 9(5) IS GLOBAL.
97. What is the Purpose of POINTER Phrase in STRING command
A. The Purpose of POINTER phrase is to specify the leftmost position within receiving field where the first transferred character will be stored
98.How do we get currentdate from system with century?
A. By using Intrinsic function, FUNCTION CURRENT-DATE
99.what is the difference between search and search all in the table handling?
A. Search is a linear search and search all is a binary search.
100.What is the maximum length of a field you can define using COMP-3?
A. 10 Bytes (S9(18) COMP-3).
101.How many Sections are there in Data Division?.
A. SIX SECTIONS 1.’FILE SECTION’ 2.’WORKING-STORAGE SECTION’ 3.’LOCAL-STORAGE SECTION’ 4.’SCREEN SECTION’ 5.’REPORT SECTION’ 6.’LINKAGE SECTION’
In COBOL II, there are only 4 sections. 1.’FILE SECTION’ 2.’WORKING-STORAGE SECTION’ 3.’LOCAL-STORAGE SECTION’ 4.’LINKAGE SECTION’.
102.How can I tell if a module is being called DYNAMICALLY or STATICALLY?
A. The ONLY way is to look at the output of the linkage editor (IEWL)or the load module itself. If the module is being called DYNAMICALLY then it will not exist in the main module, if it is being called STATICALLY then it will be seen in the load module. Calling a working storage variable, containing a program name, does not make a DYNAMIC call. This type of calling is known as IMPLICITE calling as the name of the module is implied by the contents of the working storage variable. Calling a program name literal (CALL).
103.What is the difference between a DYNAMIC and STATIC call in COBOL.
A. To correct an earlier answer:All called modules cannot run standalone if they require program variables passed to them via the LINKAGE section. DYNAMICally called modules are those that are not bound with the calling program at link edit time (IEWL for IBM) and so are loaded from the program library (joblib or steplib) associated with the job. For DYNAMIC calling of a module the DYNAM compiler option must be chosen, else the linkage editor will not generate an executable as it will expect null address resolution of all called modules. A STATICally called module is one that is bound with the calling module at link edit, and therefore becomes part of the executable load module.
104.What is the difference between PIC 9.99 and 9v99?
A. PIC 9.99 is a FOUR-POSITION field that actually contains a decimal point where as PIC 9v99 is THREE-POSITION numeric field with implied or assumed decimal position.
105.How is PIC 9.99 is different from PIC 9v99?
A. PIC 9.99 is a four position field that actually contains a decimal point where as 9v99 is a three position numeric field with an implied or assumed decimal point.
106.what is Pic 9v99 Indicates?
A. PICTURE 9v99 is a three position Numeric field with an implied or assumed decimal point after the first position; the v means an implied decimal point.
107.what guidelines should be followed to write a structured COBOL program?
108.Read the following code.
01 ws-n PIC 9(2) value zero.
a-para.
move 5 to ws-n.
perform b-para ws-n times.
b-para.
move 10 to ws-n.
How many times will b-para be executed ?
A. 5 Times only. it will not take the value 10 that is initialized in the loop.
109.What are some examples of command terminators?
A. END-IF, END-EVALUATE
110.What care has to be taken to force program to execute above 16 Meg line?
A. Make sure that link option is AMODE=31 and RMODE=ANY. Compile option should never have SIZE(MAX).BUFSIZE can be 2K, efficient enough.
111.Give some advantages of REDEFINES clause.
A. You can REDEFINE a Variable from one PICTURE class to another PICTURE class by using the same memory location. By REDEFINES we can INITIALISE the variable in WORKING-STORAGE Section itself.3. We can REDEFINE a Single Variable into so many sub-variables.(This facility is very useful in solving Y2000 Problem.)
112.Why do we code s9(4)comp. Inspite of knowing comp-3 will occupy less space.
A. Here s9(4)comp is small integer ,so two words equal to 8 bytes. Totally it will occupy 2 bytes(4 words).here in s9(4) comp-3 as one word is equal to 1/2 byte.4 words equal to 2 bytes and sign will occupy 1/2 bytes totally it will occupy 3 bytes.
113.The maximum number of dimensions that an array can have in COBOL-85 is ________.
Answer: SEVEN in COBOL – 85 and THREE in COBOL – 84
114.Name the divisions in a COBOL program.
A. IDENTIFICATION DIVISION, ENVIRONMENT DIVISION, DATA DIVISION, PROCEDURE DIVISION.
115.What are the different data types available in COBOL?
A. Alpha-numeric (X), alphabetic (A) and numeric (9).
116.What is 77 level used for ?
A. Elementary level item. Cannot be subdivisions of other items (cannot be qualified), nor can they be subdivided themselves.
117.What is 88 level used for ?
A. For defining condition names.
118.What is level 66 used for ?
A. For RENAMES clause.
119.What does the IS NUMERIC clause establish?
A. IS NUMERIC can be used on alphanumeric items, signed numeric & packed decimal items and unsigned 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 – .
120.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?
A. Must use compiler option SSRANGE if you want array bounds checking. Default is NOSSRANGE.
121. What is the difference between performing a SECTION and a PARAGRAPH?
A. 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.
122.Can I redefine an X(200) field with a field of X(100) ?
123.What does EXIT do?
A. Does nothing ! If used, must be the only sentence within a paragraph.
124.Can I redefine an X(100) field with a field of X(200)?
A. Yes. Redefines just causes both fields to start at the same location. For example:
01 WS-TOP PIC X(1)
01 WS-TOP-RED REDEFINES WS-TOP PIC X(2).
If you MOVE ‘12′ to WS-TOP-RED,
DISPLAY WS-TOP will show 1 while
DISPLAY WS-TOP-RED will show 12.
125.Can I redefine an X(200) field with a field of X(100) ?
A. Yes.
126.What do you do to resolve SOC-7 error?
A. Basically you need to correcting the offending data. Many times the reason for SOC7 is an un-initialized numeric item. Examine that possibility first. Many installations provide you a dump for run time abends ( it can be generated also by calling some subroutines or OS services thru assembly language). These dumps provide the offset of the last instruction at which the abend occurred. Examine the compilation output XREF listing to get the verb and the line number of the source code at this offset. Then you can look at the source code to find the bug. To get capture the runtime dumps, you will have to define some datasets (SYSABOUT etc ) in the JCL. If none of these are helpful, use judgement and DISPLAY to localize the source of error. You may even use batch program debugging tools.
127.How is sign stored in Packed Decimal fields and Zoned Decimal fields?
A. Packed Decimal fields: Sign is stored as a hex value in the last nibble (4 bits ) of the storage. Zoned Decimal fields: As a default, sign is over punched with the numeric value stored in the last bite.
128.How is sign stored in a comp-3 field?
A. It is stored in the last nibble. For example if your number is +100, it stores hex 0C in the last byte, hex 1C if your number is 101, hex 1D if the number is -101, hex 2D if the number is -102 etc…
129.How is sign stored in a COMP field ?
A. In the most significant bit. Bit is on if -ve, off if +ve.
130.What is the difference between COMP & COMP-3 ?
A. COMP is a binary storage format while COMP-3 is packed decimal format.
131.What is COMP-1? COMP-2?
COMP-2 – Double precision floating point. Uses 8 bytes.
132.How do you define a variable of COMP-1? COMP-2?
A. No picture clause to be given. Example 01 WS-VAR USAGE COMP-1.
133.How many bytes does a S9(7) COMP-3 field occupy ?
A. Will take 4 bytes. Sign is stored as hex value in the last nibble.
General formula is INT((n/2) + 1)), where n=7 in this example.
134.How many bytes does a S9(7) SIGN TRAILING SEPARATE field occupy ?
A. Will occupy 8 bytes (one extra byte for sign).
135.What is the maximum size of a 01 level item in COBOL I? in COBOL II?
136.What is COMP SYNC?
A. Causes the item to be aligned on natural boundaries. Can be SYNCHRONIZED LEFT or RIGHT.
For binary data items, the address resolution is faster if they are located at word boundaries in the memory. For example, on main frame the memory word size is 4 bytes. This means that each word will start from an address divisible by 4. If my first variable is x(3) and next one is s9(4) comp, then if you do not specify the SYNC clause, S9(4) COMP will start from byte 3 ( assuming that it starts from 0 ). If you specify SYNC, then the binary data item will start from address 4. You might see some wastage of memory, but the access to this comp field is faster.
137.How do you reference the following file formats from COBOL programs?
138.What are different file OPEN modes available in COBOL? In which modes are the files Opened to write.
A. Different Open modes for files are INPUT, OUTPUT, I-O and EXTEND. Of which Output and Extend modes are used to write new records into a file.
139.In the JCL, how do you define the files referred to in a subroutine?
A. Supply the DD cards just as you would for files referred to in the main program.
140.Can you REWRITE a record in an ESDS file? Can you DELETE a record from it?
A. Can rewrite(record length must be same), but not delete.
141.What is file status 92?
A. Logic error. e.g., a file is opened for input and an attempt is made to write to it.
142.What is file status 39?
A. Mismatch in LRECL or BLOCKSIZE or RECFM between your COBOL pgm & the JCL (or the dataset label). You will get file status 39 on an OPEN.
143.What is Static, Dynamic linking ?
A. In static linking, the called subroutine is link-edited into the calling program , while in dynamic linking, the subroutine & the main program will exist as separate load modules. You choose static/dynamic linking by choosing either the DYNAM or NODYNAM link edit option. (Even if you choose NODYNAM, a CALL identifier (as opposed to a CALL literal), will translate to a DYNAMIC call).
A statically called subroutine will not be in its initial state the next time it is called unless you explicitly use INITIAL or you do a CANCEL. A dynamically called routine will always be in its initial state.
144.Explain NEXT and CONTINUE verbs for file handling.
A The Continue verb is used for a situation where there in no EOF condition. i.e. The records are to be accessed again and again in a file. Whereas in the next verb the indexed file is accessed sequentially, whence when index clause is accessed sequentially read next record command is used.
145.What is AMODE(24), AMODE(31), RMODE(24) and RMODE(ANY)? (applicable to only MVS/ESA).
A. These are compile/link edit options. AMODE – Addressing mode. RMODE – Residency mode.
AMODE(24) – 24 bit addressing. AMODE(31) – 31 bit addressing. AMODE(ANY) – Either 24 bit or 31 bit addressing depending on RMODE. RMODE(24) – Resides in virtual storage below 16 Meg line. Use this for 31 bit programs that call 24 bit programs. (OS/VS Cobol pgms use 24 bit addresses only). RMODE(ANY) – Can reside above or below 16 Meg line.
146.What compiler option would you use for dynamic linking?
147.What is SSRANGE, NOSSRANGE ?
A. These are compiler options w.r.t subscript out of range checking. NOSSRANGE is the default and if chosen, no run time error will be flagged if your index or subscript goes out of the permissible range.
148.How do you set a return code to the JCL from a COBOL program?
A. Move a value to RETURN-CODE register. RETURN-CODE should not be declared in your program.
149.How can you submit a job from COBOL programs?
A. Write JCL cards to a dataset with
//xxxxxxx SYSOUT=(A,INTRDR) where ‘A’ is output class, and dataset should be opened for output in the program. Define a 80 byte record layout for the file.
150.What are the differences between OS VS COBOL and VS COBOL II?
Table of Contents:
1 FAQ
1.1 Whenever I FTP a file, it puts in ^M at the end of each line. How do I remove them?
1.3 My group has a very long name, can I have vi type it out for me?
1.4 Escaping to the Shell with the:! Command
1.5 Incorporating Shell Output Via the: r ! Command
1.6 Can I import the output of a command line into vi?
2.2 How do I search for a word with blank spaces around it?
2.3 How do I create a temp file while in vi without knowing the filename of the file I’m editing?
2.6 How do I execute the contents of my file without exiting or saving my vi session?
Ø If you have tried: 1,$ s/^M//g you know that it doesn’t work. The ^M character is a single character which is created when transferring an ASCII file in BINARY mode. This usually happen when transferring from NT to UNIX. What you need to know here is that the ^M character is the Enter key.
Ø VI allows you to duplicate the Enter key, or any other non-alphabet key (e.g. Esc, Backspace, Delete, etc.). Test it out by opening a line in vi and typing the following:
Control-V followed by Enter
Control-V followed by Backspace
Control-V followed by Delete
Ø Now that you know how to generate a control key let’s remove all those pesky ^M’s:
:1,$ s/Control-V followed by Enter//g
You should see the following:
:1,$ s/^M//g
Does your file look cleaner now?
Ø Let’s use your knowledge of the :map command and the ctrl-v combination to create the above map:
:map # O ABC Services, Inc.Control-V followed by Enter Control-V followed by EnterCalifornia, USAControl-V followed by Esc
Type the above in one line.
You should see the following:
:map # O ABC Services, Inc.^M^MCalifornia, USA^[
Ø Test your map out by moving your cursor to the middle of your file and pressing the # key (shift-3). You should see either:
ABC Services, Inc.
California, USA
or
ABC Services, Inc.
California, USA
Depending on whether your autoindent is set (remember: set ai?).
The: abbreviate command makes life easier for you when you are in the insert/append mode. The: abbreviate command can be
abbreviated to:
:ab
Ø If your group name is UNIX Software System Support, you can have vi abbreviate it to sss. All you have to do is:
: abbreviate sss UNIX Software System Support
or
: ab sss UNIX Software System Support
Ø Now test your abbreviation out by opening up a line and start typing the following:
I have been with the sss Team for # months.
Ø You should see sss change to UNIX Software System Support as soon as you hit the spacebar after sss.
Ø What do you think would happen if you are writing a children's book and you type the following?
This is a snake. A snake goes hisss.
Try it out.
Ø You can escape to the shell and run commands without exiting your vi session. Many times you do this because you are not ready to do a: wq yet. Or you are afraid that opening another xterm to look at your lpstat command will crash your laptop.
Ø For example, you want to check if your print job has completed yet, you can run the following command while in vi:
:!lpstat
The ! takes you into a child shell to execute your command. and prompts you to [Hit return to continue] when you’re done.
Ø Many times when you are documenting, you want to insert the contents of a file, or standard output into your document. This command does exactly that.
Ø You are documenting a script and would like to import some output into your documenting. Your goal is to show the permissions for the file, and the contents of the file. One way it to cut and paste with 2 windows open.
Ø The vi way would be to move your cursor to where you want the output to appear in your file and type:
:r !ll ring10
You see the following in your file:
-rwxr-xr-x 1 sss3 sss 54 Jan 27 11:10 ring10
Ø Then move the cursor to where you want the content of your file and type:
:r ring10
You see the following in your file:
for i in 0 1 2 3 4 5 6 7 8 9
do
echo ^G
sleep 1
done
Here is how to copy the required number of lines from one file to another in VI editor. First use the following key combinations in the source file.
Ø Press ESCAPE
Ø Press Shift “(Shift double quotes)
Ø Press a
Ø Press the number of lines you want to copy
Ø press y followed by another y
Ø Now press ” : ” (COLON) to get the vi prompt.
Ø Hit e “Destination file name”
Ø Once you enter the Destination file go to the line where you want the lines copied to be inserted.
Ø Press ESCAPE.
Ø Press SHIFT “(Double quotes).
Ø Press a.
Ø Press p.
Ø The lines get copied.
The key here is to plan ahead. This is one way I would approach it:
Create an abbreviation first:
:ab str s/this/that/g
Then you can execute your replacement as often as you want on any line(s) by typing:
:10,15 str space
:20,25 str space
:40,$-2 str space
Note that the str MUST be followed by a space for the :ab to take effect.
Type the following:
/\[space]string\[space][enter]
Don’t type each character in the square brackets (or the square bracket).
One way is to use :w %.tmp
This says write (save) contents to the filename.tmp. % is a placeholder for the name of the file.
Type the following
:s/[a-z]/\u&/g
The \u changes case to upper (\l to lower)
The & is the placeholder for each pattern/character found.
Content of vi’ed file:
filea
fileb
:
filex
lastfile
Type the following:
:1,$ s#.*#mv & /tmp/&#
The & is the placeholder for each pattern/character found.
Type the following:
:w !sh
This essentially means to write the entire editing buffer to a shell for execution. At this point you can quit vi, and the job is
done.
Content of vi’ed file:
c04821
c04822
c05035
:
:
c05555
c15556
Type the following on the same line (no carraige returns):
:1,$ s#.*#grep -v ^&: pwd > /etc/passwd; awk -F: ‘/^&:/ {print $1″:NONE:”$3″:”$4″:”$5″:”$6″:”$7}’ pwd >> /etc/passwd;
cat /etc/passwd >
pwd#
: Type the following (don’t forget the space before the asterix/star character):
g/^ *$/d
]]>
Ans) LMI (Local Management Interface)
2) DLCIs are ________ significant.(Hint: Is it locally or globally?).
Ans) locally
3) The algorithm used by the link-state protocols to calculate the best routes is_______.
Ans) SPF/Djkistra’s Algorithm
4) EIGRP decides if a route can be a feasible successor if the Advertised distance of that route from the neighbor is ________ than the feasible distance of that route.(Hint: Greater/Lesser).
Ans) lesser
5) What is the link-state protocol that supports both OSI and IP layers?
Ans) IS-IS
6) From which memory does the router boot without the boot system command by default? Ans) FLASH
7) All the line vtys need not have the same password. [Yes or no]?? Ans) YES
8) Which is the command to encrypt all the passwords at a time? Ans) Service Password encryption
9) Which command is used for changing the number of commands to be recalled? Ans) Terminal History Size history size
10) Which protocol relies on neighbor tables, topology tables, route states, and route tagging? Ans) EIGRP
11) The maximum number of satellite hops allowed in voice communication is Ans) 2 hops
12) What action is taken when the processor under execution is interrupted by a non-maskable interrupt?
a) Processor serves the interrupt request after completing the execution of the current instruction.
b) Processor serves the interrupt request after completing the current task.
c) Processor serves the interrupt request immediately.
d) Processor serving the interrupt request depends upon the priority of the current task under execution.
Ans) a
13) What is the type of signaling used between two exchanges?
Ans) Inband
14) A software that allows a personal computer to pretend as a computer terminal is …. Ans) Terminal emulation
15) If the period length T of a pulse is increased, the amplitude of the dc term will …. Ans) Decrease
16) The highest harmonic generated by human voice is ——– Ans) 3 KHz
17) Any electronic device on a network is called as —– Ans) Node
18) Which equipment is installed in a PC and allows the PC to get connected to a network? Ans) NIC
19) What is the result of segmenting a network with a bridge? Will it increase or decrease the number of collision domains? Ans) Increase
20) What is the link state routing protocol used in TCP/IP protocol stack? Ans) OSPF
21) What is the total bandwidth of all the channels on a PRI circuit? Ans) 1.544 Mbps
22) What is the bandwidth capacity of a ISDN B channel? Ans) 64 Kbps
23) What type of connector is used in a 10base2 network? Ans) BNC (British Naval Connector)
24) What does the “F” stand for in 10baseF and the “T” stand for in 10baseT? Ans) Optical Fiber Cable, Twisted Pair Cable
25) What protocol provides dial-up telephone connections using the Network Layer IP protocol? Ans) SLIP
26) The size of UDP header is Ans) 8 bytes
27) IP corresponds to which OSI layer? Ans) Network
28) Which form of DSl theoretically provides the fastest service? Ans) VDSL
29) Which PDU is employed at the Transport Layer? Ans) Segment
30) Which OSI layer performs error detection functions? Ans) Data Link Layer
31) The encapsulation of packets inside packets of a different protocol to create and maintain the virtual circuit is termed as …… Ans) Tunnelling
32) Who is responsible for the invention of Ethernet? Ans) D.R.Boggs along with Bob Metcalfe
33) Thicknet is a colloquial name for which Ethernet Standard? Ans) 10 Base 5
34) On Ethernet LAN s the Ethernet address is also known as ……. Ans) MAC address or Physical Address or Hardware Address
35) What is the basic unit of Ethernet traffic? Ans) Frames
36) Routing occurs at what layer of OSI model? Ans) Network
37) IP RIP runs over what UDP port number? Ans) 520
38) Which BGP version is most widely used today? Ans) 4
39) What hardware port is typically designed to connect a Cisco router for modem access? Ans) The Auxiliary Port
40) How many digits are there in MAC address? Ans) 12
41) Which of the following is the fastest protocol?
a) IPX/SPX
b) NetBEUI
c) APPLE TALK
d) TCP/IP Ans) NetBEUI
42) A proxy server is what level of Firewall? Ans) Application Level
43) In which layer of OSI model will the MAC sub layers fit? Ans) Data Link Layer
44) What is the default port of FTP? Ans) 21
45) Which Protocol uses token Passing in BUS topology? Ans) 802.4
46) Which protocol is responsible for sending the all important email? Ans) SMTP
47) What is the maximum number of computers on a LAN in the Star Topology? Ans) 1024
48) What is the maximum distance for fiber optic cable? Ans) 25km
49) What is the distance constraint of ADSL circuit? Ans) 5.4 Km
50) What is the maximum number of PPTP and L2TP connections that can be supported on a Windows 2003 Enterprise edition?
Ans) 1000 and 1000
]]>