Oracle Interview Questions – Part 7

Q.What are the built-ins that are used to Attach an LOV programmatically to an item?

(by setting the LOV_NAME property)

Q.Any attempt to navigate programmatically to disabled form in a call_form stack is allowed?

Q.Use the Add_group_row procedure to add a row to a static record group 1. true or false?


Q.How does one backup archived log files? (for DBA )

One can backup archived log files using RMAN or any operating system backup utility. Remember to delete files after backing them up to prevent the archive log directory from filling up. If the archive log directory becomes full, your database will hang! Look at this simple RMAN backup script:
RMAN> run {
2> allocate channel dev1 type disk;
3> backup
4> format ‘/app/oracle/arch_backup/log_t%t_s%s_p%p’
5> (archivelog all delete input);
6> release channel dev1;
7> }

Q.How does one do on-line database backups? (for DBA )
Each tablespace that needs to be backed-up must be switched into backup mode before copying the files out to secondary storage (tapes). Look at this simple example.
! cp xyfFile1 /backupDir/
It is better to backup tablespace for tablespace than to put all tablespaces in backup mode. Backing them up separately incurs less overhead. When done, remember to backup your control files. Look at this example:
ALTER SYSTEM SWITCH LOGFILE; — Force log switch to update control file headers
NOTE: Do not run on-line backups during peak processing periods. Oracle will write complete database blocks instead of the normal deltas to redo log files while in backup mode. This will lead to excessive database archiving and even database freezes.

Q.How does one backup a database using RMAN? (for DBA )
The biggest advantage of RMAN is that it only backup used space in the database. Rman doesn’t put tablespaces in backup mode, saving on redo generation overhead. RMAN will re-read database blocks until it gets a consistent image of it. Look at this simple backup example.
rman target sys/*** nocatalog
run {
allocate channel t1 type disk;
format ‘/app/oracle/db_backup/%d_t%t_s%s_p%p’
( database );
release channel t1;
Example RMAN restore:
rman target sys/*** nocatalog
run {
allocate channel t1 type disk;
# set until time ‘Aug 07 2000 :51′;
restore tablespace users;
recover tablespace users;
release channel t1;
The examples above are extremely simplistic and only useful for illustrating basic concepts. By default Oracle uses the database controlfiles to store information about backups. Normally one would rather setup a RMAN catalog database to store RMAN metadata in. Read the Oracle Backup and Recovery Guide before implementing any RMAN backups.
Note: RMAN cannot write image copies directly to tape. One needs to use a third-party media manager that integrates with RMAN to backup directly to tape. Alternatively one can backup to disk and then manually copy the backups to tape.

Q.What are the different file extensions that are created by oracle reports?

Rep file and Rdf file.

Q.What is strip sources generate options?

Removes the source code from the library file and generates a library files that contains only pcode. The resulting file can be used for final deployment, but can not be subsequently edited in the designer.ex. f45gen module=old_lib.pll userid=scott/tiger strip_source YES output_file

Q.How does one put a database into ARCHIVELOG mode? (for DBA )

The main reason for running in archivelog mode is that one can provide 24-hour availability and guarantee complete data recoverability. It is also necessary to enable ARCHIVELOG mode before one can start to use on-line database backups. To enable ARCHIVELOG mode, simply change your database startup command script, and bounce the database:
SQLPLUS> connect sys as sysdba
SQLPLUS> startup mount exclusive;
SQLPLUS> alter database archivelog;
SQLPLUS> archive log start;
SQLPLUS> alter database open;
NOTE1: Remember to take a baseline database backup right after enabling archivelog mode. Without it one would not be able to recover. Also, implement an archivelog backup to prevent the archive log directory from filling-up.
NOTE2: ARCHIVELOG mode was introduced with Oracle V6, and is essential for database point-in-time recovery. Archiving can be used in combination with on-line and off-line database backups.
NOTE3: You may want to set the following INIT.ORA parameters when enabling ARCHIVELOG mode: log_archive_start=TRUE, log_archive_dest=… and log_archive_format=…
NOTE4: You can change the archive log destination of a database on-line with the ARCHIVE LOG START TO ‘directory'; statement. This statement is often used to switch archiving between a set of directories.
NOTE5: When running Oracle Real Application Server (RAC), you need to shut down all nodes before changing the database to ARCHIVELOG mode.

Q.What is the basic data structure that is required for creating an LOV?

Record Group.

Q.Does Oracle write to data files in begin/hot backup mode? (for DBA )

Oracle will stop updating file headers, but will continue to write data to the database files even if a tablespace is in backup mode.
In backup mode, Oracle will write out complete changed blocks to the redo log files. Normally only deltas (changes) are logged to the redo logs. This is done to enable reconstruction of a block if only half of it was backed up (split blocks). Because of this, one should notice increased log activity and archiving during on-line backups.

Q.What is system.coordination_operation?

It represents the coordination causing event that occur on the master block in master-detail relation.

Q.What are the different styles of activation of ole Objects?
In place activationExternal activation

Q.How do you reference a Parameter?

In Pl/Sql, You can reference and set the values of form parameters using bind variables syntax. Ex. PARAMETER name = ” or :block.item = PARAMETER Parameter name

Q.What is synchronize?

It is a terminal screen with the internal state of the form. It updates the screen display to reflect the information that oracle forms has in its internal representation of the screen.

Q.What use of command line parameter cmd file?

It is a command line argument that allows you to specify a file that contain a set of arguments for r20run.

Q.What is a Text_io Package?
It allows you to read and write information to a file in the file system.

Q.What is forms_DDL?

Issues dynamic Sql statements at run time, including server side pl/SQl and DDL

Q.How is link tool operation different bet. reports 2 & 2.5?
In Reports 2.0 the link tool has to be selected and then two fields to be linked are selected and the link is automatically created. In 2.5 the first field is selected and the link tool is then used to link the first field to the second field.

Q.What are the built-ins that are used for setting the LOV properties at runtime?

set_lov_property Q.What are the built-ins used for processing rowQ.?


Q.What are the built-in used for getting cell values?


Q.Atleast how many set of data must a data model have before a data model can be base on it?


Q.What is a difference between pre-select and pre-query?

Fires during the execute query and count query processing after oracle forms constructs the select statement to be issued, but before the statement is actually issued. The pre-query trigger fires just before oracle forms issues the select statement to the database after the operator as define the example records by entering the query criteria in enter query mode.Pre-query trigger fires before pre-select trigger.

Q.To execute row from being displayed that still use column in the row which property can be used?
Format trigger.

Q.What is the difference between object embedding & linking in Oracle forms?
In Oracle forms, Embedded objects become part of the form module, and linked objects are references from a form module to a linked source file.

Q.What are different types of modules available in oracle form?

Form module – a collection of objects and code routines Menu modules – a collection of menus and menu item commands that together make up an application menu library module – a collection of user named procedures, functions and packages that can be called from other modules in the application

Q.What is the remove on exit property?

For a modelless window, it determines whether oracle forms hides the window automatically when the operators navigates to an item in the another window.

Q.What is the advantage of the library?
Libraries provide a convenient means of storing client-side program units and sharing them among multiple applications. Once you create a library, you can attach it to any other form, menu, or library modules. When you can call library program units from triggers menu items commands and user named routine, you write in the modules to which you have attach the library. When a library attaches another library, program units in the first library can reference program units in the attached library. Library support dynamic loading-that is library program units are loaded into an application only when needed. This can significantly reduce the run-time memory requirements of applications.

Q.What is lexical reference? How can it be created?

Lexical reference is place_holder for text that can be embedded in a sql statements. A lexical reference can be created using & before the column or parameter name.

Q.Name of the functions used to get/set canvas properties?
Get_view_property, Set_view_property

Q.What is WHEN-Database-record trigger?
Fires when oracle forms first marks a record as an insert or an update. The trigger fires as soon as oracle forms determines through validation that the record should be processed by the next post or commit as an insert or update. c generally occurs only when the operators modifies the first item in the record, and after the operator attempts to navigate out of the item.

Q.What are built-ins associated with timers?


Q.What are the built-ins used for finding object ID functions?