Set - 2

Question 1 :

What is a SNAPSHOT ?

Answer :

Snapshots are read-only copies of a master table located on a remote node which is periodically refreshed to reflect changes made to the master table.


Question 2 :

What is the mechanism provided by ORACLE for table replication ?

Answer :

Snapshots and SNAPSHOT LOGs


Question 3 :

What is snapshots?

Answer :

Snapshot is an object used to dynamically replicate data between distribute database at specified time intervals. In ver 7.0 they are read only.


Question 4 :

What are the various type of snapshots?

Answer :

Simple and Complex.


Question 5 :

Describe two phases of Two-phase commit ?

Answer :

Prepare phase - The global coordinator (initiating node) ask a participants to prepare (to promise to commit or rollback the transaction, even if there is a failure) Commit - Phase - If all participants respond to the coordinator that they are prepared, the coordinator asks all nodes to commit the transaction, if all participants cannot prepare, the coordinator asks all nodes to roll back the transaction.


Question 6 :

What is snapshot log ?

Answer :

It is a table that maintains a record of modifications to the master table in a snapshot. It is stored in the same database as master table and is only available for simple snapshots. It should be created before creating snapshots.


Question 7 :

What are the benefits of distributed options in databases?

Answer :

Database on other servers can be updated and those transactions can be grouped together with others in a logical unit.
Database uses a two phase commit.


Question 8 :

What are the options available to refresh snapshots ?

Answer :

COMPLETE - Tables are completely regenerated using the snapshots query and the master tables every time the snapshot referenced.
FAST - If simple snapshot used then a snapshot log can be used to send the changes to the snapshot tables.
FORCE - Default value. If possible it performs a FAST refresh; Otherwise it will perform a complete refresh.


Question 9 :

What is a SNAPSHOT LOG ?

Answer :

A snapshot log is a table in the master database that is associated with the master table. ORACLE uses a snapshot log to track the rows that have been updated in the master table. Snapshot logs are used in updating the snapshots based on the master table.


Question 10 :

What is Distributed database ?

Answer :

A distributed database is a network of databases managed by multiple database servers that appears to a user as single logical database. The data of all databases in the distributed database can be simultaneously accessed and modified.


Question 11 :

How can we reduce the network traffic?

Answer :

- Replication of data in distributed environment.
- Using snapshots to replicate data.
- Using remote procedure calls.


Question 12 :

Differentiate simple and complex, snapshots ?

Answer :

- A simple snapshot is based on a query that does not contains GROUP BY clauses, CONNECT BY clauses, JOINs, sub-query or snashot of operations.
- A complex snapshots contain atleast any one of the above.


Question 13 :

What are the Built-ins used for sending Parameters to forms?

Answer :

You can pass parameter values to a form when an application executes the call_form, New_form, Open_form or Run_product.


Question 14 :

Can you have more than one content canvas view attached with a window?

Answer :

Yes. Each window you create must have atleast one content canvas view assigned to it. You can also create a window that has manipulated content canvas view. At run time only one of the content canvas views assign to a window is displayed at a time.


Question 15 :

Is the After report trigger fired if the report execution fails?

Answer :

Yes.


Question 16 :

Does a Before form trigger fire when the parameter form is suppressed?

Answer :

Yes.


Question 17 :

What is SGA?

Answer :

The System Global Area in an Oracle database is the area in memory to facilitate the transfer of information between users. It holds the most recently requested structural information between users. It holds the most recently requested structural information about the database. The structure is database buffers, dictionary cache, redo log buffer and shared pool area.


Question 18 :

What is a shared pool?

Answer :

The data dictionary cache is stored in an area in SGA called the shared pool. This will allow sharing of parsed SQL statements among concurrent users.


Question 19 :

What is mean by Program Global Area (PGA)?

Answer :

It is area in memory that is used by a single Oracle user process.


Question 20 :

What is a data segment?

Answer :

Data segment are the physical areas within a database block in which the data associated with tables and clusters are stored.


Question 21 :

What are the factors causing the reparsing of SQL statements in SGA?

Answer :

Due to insufficient shared pool size.
Monitor the ratio of the reloads takes place while executing SQL statements. If the ratio is greater than 1 then increase the SHARED_POOL_SIZE.


Question 22 :

What are clusters?

Answer :

Clusters are groups of one or more tables physically stores together to share common columns and are often used together.


Question 23 :

What is cluster key?

Answer :

The related columns of the tables in a cluster are called the cluster key.


Question 24 :

Do a view contain data?

Answer :

Views do not contain or store data.


Question 25 :

What is user Account in Oracle database?

Answer :

A user account is not a physical structure in database but it is having important relationship to the objects in the database and will be having certain privileges.


Question 26 :

How will you enforce security using stored procedures?

Answer :

Don't grant user access directly to tables within the application. Instead grant the ability to access the procedures that access the tables. When procedure executed it will execute the privilege of procedures owner. Users cannot access tables except via the procedure.


Question 27 :

What are the dictionary tables used to monitor a database space?

Answer :

DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.


Question 28 :

Can a property clause itself be based on a property clause?

Answer :

Yes


Question 29 :

If a parameter is used in a query without being previously defined, what diff. exist between. report 2.0 and 2.5 when the query is applied?

Answer :

While both reports 2.0 and 2.5 create the parameter, report 2.5 gives a message that a bind parameter has been created.


Question 30 :

What are the sql clauses supported in the link property sheet?

Answer :

Where start with having.


Question 31 :

What is trigger associated with the timer?

Answer :

When-timer-expired.


Question 32 :

What are the trigger associated with image items?

Answer :

When-image-activated fires when the operators double clicks on an image itemwhen-image-pressed fires when an operator clicks or double clicks on an image item


Question 33 :

What are the different windows events activated at runtimes?

Answer :

When_window_activated
When_window_closed
When_window_deactivated
When_window_resized
Within this triggers, you can examine the built in system variable system. event_window to determine the name of the window for which the trigger fired.


Question 34 :

When do you use data parameter type?

Answer :

When the value of a data parameter being passed to a called product is always the name of the record group defined in the current form. Data parameters are used to pass data to products invoked with the run_product built-in subprogram.


Question 35 :

What is difference between open_form and call_form?

Answer :

when one form invokes another form by executing open_form the first form remains displayed, and operators can navigate between the forms as desired. when one form invokes another form by executing call_form, the called form is modal with respect to the calling form. That is, any windows that belong to the calling form are disabled, and operators cannot navigate to them until they first exit the called form.


Question 36 :

What is new_form built-in?

Answer :

When one form invokes another form by executing new_form oracle form exits the first form and releases its memory before loading the new form calling new form completely replace the first with the second. If there are changes pending in the first form, the operator will be prompted to save them before the new form is loaded.


Question 37 :

What is the "LOV of Validation" Property of an item? What is the use of it?

Answer :

When LOV for Validation is set to True, Oracle Forms compares the current value of the text item to the values in the first column displayed in the LOV. Whenever the validation event occurs. If the value in the text item matches one of the values in the first column of the LOV, validation succeeds, the LOV is not displayed, and processing continues normally. If the value in the text item does not match one of the values in the first column of the LOV, Oracle Forms displays the LOV and uses the text item value as the search criteria to automatically reduce the list.


Question 38 :

What is the diff. when Flex mode is mode on and when it is off?

Answer :

When flex mode is on, reports automatically resizes the parent when the child is resized.


Question 39 :

What is the diff. when confine mode is on and when it is off?

Answer :

When confine mode is on, an object cannot be moved outside its parent in the layout.


Question 40 :

What are visual attributes?

Answer :

Visual attributes are the font, color, pattern proprieties that you set for form and menu objects that appear in your application interface.


Question 41 :

Which of the two views should objects according to possession?

Answer :

view by structure.


Question 42 :

What are the two types of views available in the object navigator(specific to report 2.5)?

Answer :

View by structure and view by type .


Question 43 :

What are the vbx controls?

Answer :

Vbx control provide a simple method of building and enhancing user interfaces. The controls can use to obtain user inputs and display program outputs.vbx control where originally develop as extensions for the ms visual basic environments and include such items as sliders, rides and knobs.


Question 44 :

What is the use of transactional triggers?

Answer :

Using transactional triggers we can control or modify the default functionality of the oracle forms.


Question 45 :

How do you create a new session while open a new form?

Answer :

Using open_form built-in setting the session option Ex. Open_form('Stocks ',active, session). when invoke the multiple forms with open form and call_form in the same application, state whether the following are true/False


Question 46 :

What are the ways to monitor the performance of the report?

Answer :

Use reports profile executable statement. Use SQL trace facility.


Question 47 :

If two groups are not linked in the data model editor, What is the hierarchy between them?

Answer :

Two group that is above are the left most rank higher than the group that is to right or below it.


Question 48 :

An open form can not be execute the call_form procedure if you chain of called forms has been initiated by another open form?

Answer :

True


Question 49 :

Explain about horizontal, Vertical tool bar canvas views?

Answer :

Tool bar canvas views are used to create tool bars for individual windows. Horizontal tool bars are display at the top of a window, just under its menu bar. Vertical Tool bars are displayed along the left side of a window


Question 50 :

What is the purpose of the product order option in the column property sheet?

Answer :

To specify the order of individual group evaluation in a cross products.


Question 51 :

What is the use of image_zoom built-in?

Answer :

To manipulate images in image items.


Question 52 :

How do you reference a parameter indirectly?

Answer :

To indirectly reference a parameter use the NAME IN, COPY 'built-ins to indirectly set and reference the parameters value' Example name_in ('capital parameter my param'), Copy ('SURESH','Parameter my_param')


Question 53 :

What is a timer?

Answer :

Timer is an "internal time clock" that you can programmatically create to perform an action each time the times.


Question 54 :

What are the two phases of block coordination?

Answer :

There are two phases of block coordination: the clear phase and the population phase. During, the clear phase, Oracle Forms navigates internally to the detail block and flushes the obsolete detail records. During the population phase, Oracle Forms issues a SELECT statement to repopulate the detail block with detail records associated with the new master record. These operations are accomplished through the execution of triggers.


Question 55 :

What are Most Common types of Complex master-detail relationships?

Answer :

There are three most common types of complex master-detail relationships:
master with dependent details
master with independent details
detail with two masters


Question 56 :

What is a text list?

Answer :

The text list style list item appears as a rectangular box which displays the fixed number of values. When the text list contains values that can not be displayed, a vertical scroll bar appears, allowing the operator to view and select undisplayed values.


Question 57 :

What is term?

Answer :

The term is terminal definition file that describes the terminal form which you are using r20run.


Question 58 :

What is use of term?

Answer :

The term file which key is correspond to which oracle report functions.


Question 59 :

What is pop list?

Answer :

The pop list style list item appears initially as a single field (similar to a text item field). When the operator selects the list icon, a list of available choices appears.


Question 60 :

What is the maximum no of chars the parameter can store?

Answer :

The maximum no of chars the parameter can store is only valid for char parameters, which can be upto 64K. No parameters default to 23Bytes and Date parameter default to 7Bytes.


Question 61 :

What are the default extensions of the files created by library module?

Answer :

The default file extensions indicate the library module type and storage format .pll - pl/sql library module binary


Question 62 :

What are the Coordination Properties in a Master-Detail relationship?

Answer :

The coordination properties are
Deferred
Auto-Query
These Properties determine when the population phase of block
coordination should occur.


Question 63 :

How do you display console on a window ?

Answer :

The console includes the status line and message line, and is displayed at the bottom of the window to which it is assigned.To specify that the console should be displayed, set the console window form property to the name of any window in the form. To include the console, set console window to Null.


Question 64 :

What are the different Parameter types?

Answer :

Text ParametersData Parameters


Question 65 :

State any three mouse events system variables?

Answer :

System.mouse_button_pressedSystem.mouse_button_shift


Question 66 :

What are the types of calculated columns available?

Answer :

Summary, Formula, Placeholder column.


Question 67 :

Explain about stacked canvas views?

Answer :

Stacked canvas view is displayed in a window on top of, or "stacked" on the content canvas view assigned to that same window. Stacked canvas views obscure some part of the underlying content canvas view, and or often shown and hidden programmatically.


Question 68 :

How does one do off-line database backups? (for DBA )

Answer :

Shut down the database from sqlplus or server manager. Backup all files to secondary storage (eg. tapes). Ensure that you backup all data files, all control files and all log files. When completed, restart your database.
Do the following queries to get a list of all files that needs to be backed up:
select name from sys.v_$datafile;
select member from sys.v_$logfile;
select name from sys.v_$controlfile;
Sometimes Oracle takes forever to shutdown with the "immediate" option. As workaround to this problem, shutdown using these commands:
alter system checkpoint;
shutdown abort
startup restrict
shutdown immediate
Note that if you database is in ARCHIVELOG mode, one can still use archived log files to roll forward from an off-line backup. If you cannot take your database down for a cold (off-line) backup at a convenient time, switch your database into ARCHIVELOG mode and perform hot (on-line) backups.


Question 69 :

What is the difference between SHOW_EDITOR and EDIT_TEXTITEM?

Answer :

Show editor is the generic built-in which accepts any editor name and takes some input string and returns modified output string. Whereas the edit_textitem built-in needs the input focus to be in the text item before the built-in is executed.


Question 70 :

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

Answer :

set_item_property
get_item_property
(by setting the LOV_NAME property)


Question 71 :

How does one do on-line database backups? (for DBA )

Answer :

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.

ALTER TABLESPACE xyz BEGIN BACKUP;
! cp xyfFile1 /backupDir/
ALTER TABLESPACE xyz END BACKUP;

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
ALTER DATABASE BACKUP CONTROLFILE TO '/backupDir/control.dbf';

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.


Question 72 :

How does one backup a database using RMAN? (for DBA )

Answer :

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;
	backup 
	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.


Question 73 :

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

Answer :

Rep file and Rdf file.


Question 74 :

What is strip sources generate options?

Answer :

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


Question 75 :

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

Answer :

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.


Question 76 :

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

Answer :

Record Group.


Question 77 :

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

Answer :

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> }


Question 78 :

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

Answer :

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.


Question 79 :

What is the Maximum allowed length of Record group Column?

Answer :

Record group column names cannot exceed 30 characters.


Question 80 :

Which parameter can be used to set read level consistency across multiple queries?

Answer :

Read only


Question 81 :

What are the different types of Record Groups?

Answer :

Query Record Groups
NonQuery Record Groups
State Record Groups


Question 82 :

From which designation is it preferred to send the output to the printed?

Answer :

Previewer


Question 83 :

What are difference between post database commit and post-form commit?

Answer :

Post-form commit fires once during the post and commit transactions process, after the database commit occurs. The post-form-commit trigger fires after inserts, updates and deletes have been posted to the database but before the transactions have been finalized in the issuing the command. The post-database-commit trigger fires after oracle forms issues the commit to finalized transactions.


Question 84 :

What are the different display styles of list items?

Answer :

Pop_listText_listCombo box


Question 85 :

Which of the above methods is the faster method?

Answer :

performing the calculation in the query is faster.


Question 86 :

With which function of summary item is the compute at options required?

Answer :

percentage of total functions.


Question 87 :

What are parameters?

Answer :

Parameters provide a simple mechanism for defining and setting the valuesof inputs that are required by a form at startup. Form parameters are variables of type char,number,date that you define at design time.


Question 88 :

What are the three types of user exits available ?

Answer :

Oracle Precompiler exits, Oracle call interface, NonOracle user exits.


Question 89 :

How many windows in a form can have console?

Answer :

Only one window in a form can display the console, and you cannot change the console assignment at runtime.


Question 90 :

What is an administrative (privileged) user? (for DBA )

Answer :

Oracle DBAs and operators typically use administrative accounts to manage the database and database instance. An administrative account is a user that is granted SYSOPER or SYSDBA privileges. SYSDBA and SYSOPER allow access to a database instance even if it is not running. Control of these privileges is managed outside of the database via password files and special operating system groups. This password file is created with the orapwd utility.


Question 91 :

What are the two repeating frame always associated with matrix object?

Answer :

One down repeating frame below one across repeating frame.


Question 92 :

What are the master-detail triggers?

Answer :

On-Check_delete_masterOn_clear_detailsOn_populate_details


Question 93 :

How does one connect to an administrative user? (for DBA )

Answer :

If an administrative user belongs to the "dba" group on Unix, or the "ORA_DBA" (ORA_sid_DBA) group on NT, he/she can connect like this:
connect / as sysdba
No password is required. This is equivalent to the desupported "connect internal" method.
A password is required for "non-secure" administrative access. These passwords are stored in password files. Remote connections via Net8 are classified as non-secure. Look at this example:
connect sys/password as sysdba


Question 94 :

How does one create a password file? (for DBA )

Answer :

The Oracle Password File ($ORACLE_HOME/dbs/orapw or orapwSID) stores passwords for users with administrative privileges. One needs to create a password files before remote administrators (like OEM) will be allowed to connect.
Follow this procedure to create a new password file:
. Log in as the Oracle software owner
. Runcommand: orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID password=mypasswd
. Shutdown the database (SQLPLUS> SHUTDOWN IMMEDIATE)
. Edit the INIT.ORA file and ensure REMOTE_LOGIN_PASSWORDFILE=exclusive is set.
. Startup the database (SQLPLUS> STARTUP)
NOTE: The orapwd utility presents a security risk in that it receives a password from the command line. This password is visible in the process table of many systems. Administrators needs to be aware of this!


Question 95 :

Is it possible to modify an external query in a report which contains it?

Answer :

No.


Question 96 :

Does a grouping done for objects in the layout editor affect the grouping done in the data model editor?

Answer :

No.


Question 97 :

How does one add users to a password file? (for DBA )

Answer :

One can select from the SYS.V_$PWFILE_USERS view to see which users are listed in the password file. New users can be added to the password file by granting them SYSDBA or SYSOPER privileges, or by using the orapwd utility. GRANT SYSDBA TO scott;


Question 98 :

If a break order is set on a column would it affect columns which are under the column?

Answer :

No