ORACLE FREQUENTLY ASKED QUESTIONS - III
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> }
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.
What is the Maximum
allowed length of Record group Column?
Record group column names
cannot exceed 30 characters.
Which parameter can be
used to set read level consistency across multiple queries?
Read only
What are the different
types of Record Groups?
Query Record Groups
NonQuery Record Groups
State Record Groups
From which designation is
it preferred to send the output to the printed?
Previewer
What are difference
between post database commit and post-form commit?
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.
What are the different
display styles of list items?
Pop_listText_listCombo box
Which of the above
methods is the faster method?
performing the
calculation in the query is faster.
With which function of
summary item is the compute at options required?
percentage of total functions.
What are parameters?
Parameters provide a simple mechanism for defining and setting the values of
inputs that are required by a form at startup. Form parameters are variables of
type char, number, date that you define at design time.
What are the three types
of user exits available?
Oracle Precompiler exits, Oracle call interface, NonOracle user exits.
How many windows in a
form can have console?
Only one window in a form can display the console, and you cannot change the
console assignment at runtime.
What is an administrative
(privileged) user? (For DBA)
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.
What are the two
repeating frame always associated with matrix object?
One down repeating frame below one across repeating frame.
What are the
master-detail triggers?
On-Check_delete_masterOn_clear_detailsOn_populate_details
How does one connect to
an administrative user? (For DBA)
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
How does one create a password
file? (For DBA)
The Oracle Password File ($ORACLE_HOME/dbs/orapw or orapwSID) stores passwords
for users with administrative privileges. One needs to create a password files
before remote administrators (like OEM) will be allowed to connect.
Follow this procedure to create a new password file:
. Log in as the Oracle software owner
. Run command: orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID password=mypasswd
. Shutdown the database (SQLPLUS> SHUTDOWN IMMEDIATE)
. Edit the INIT.ORA file and ensure REMOTE_LOGIN_PASSWORDFILE=exclusive is set.
. Startup the database (SQLPLUS> STARTUP)
NOTE: The orapwd utility presents a security risk in that it receives a
password from the command line. This password is visible in the process table
of many systems. Administrators needs to be aware of this!
Is it possible to modify
an external query in a report which contains it?
No.
Does a grouping done for
objects in the layout editor affect the grouping done in the data model editor?
No.
How does one add users to
a password file? (For DBA)
One can select from the SYS.V_$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;
If a break order is set
on a column would it affect columns which are under the column?
No
Why are OPS$ accounts a
security risk in a client/server environment? (For DBA)
If you allow people to log in with OPS$ accounts from Windows Workstations, you
cannot be sure who they really are. With terminals, you can rely on operating
system passwords, with Windows, you cannot.
If you set REMOTE_OS_AUTHENT=TRUE in your init.ora file, Oracle assumes that
the remote OS has authenticated the user. If REMOTE_OS_AUTHENT is set to FALSE
(recommended), remote users will be unable to connect without a password.
IDENTIFIED EXTERNALLY will only be in effect from the local host. Also, if you
are using "OPS$" as your prefix, you will be able to log on locally
with or without a password, regardless of whether you have identified your ID
with a password or defined it to be IDENTIFIED EXTERNALLY.
Do user parameters appear
in the data modal editor in 2.5?
No
Can you pass data
parameters to forms?
No
Is it possible to link
two groups inside a cross products after the cross products group has been
created?
No
What are the different
default triggers created when Master Deletes Property is set to Non-isolated?
Master Deletes Property
Resulting Triggers
----------------------------------------------------
Non-Isolated(the default) On-Check-Delete-Master
On-Clear-Details
On-Populate-Details
What are the different
default triggers created when Master Deletes Property is set to isolated?
Master Deletes Property
Resulting Triggers
---------------------------------------------------
Isolated On-Clear-Details
On-Populate-Details
What are the different
default triggers created when Master Deletes Property is set to Cascade?
Master Deletes Property Resulting Triggers
---------------------------------------------------
Cascading On-Clear-Details
On-Populate-Details
Pre-delete
What is the diff. bet.
setting up of parameters in reports 2.0 reports2.5?
LOVs can be attached to parameters in the reports 2.5 parameter form.
What are the difference
between lov & list item?
Lov is a property whereas list item is an item. A list item can have only one
column, lov can have one or more columns.
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.
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.
What is
system.coordination_operation?
It represents the coordination causing event that occur on the master block in
master-detail relation.
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.
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.
What is a Text_io
Package?
It allows you to read and write information to a file in the file system.
What is forms_DDL?
Issues dynamic Sql statements at run time, including server side pl/Sql and DDL
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.
What are the different
styles of activation of ole Objects?
In place activationExternal activation
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
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.
Name of the functions
used to get/set canvas properties?
Get_view_property, Set_view_property
What are the built-ins
that are used for setting the LOV properties at runtime?
get_lov_property
set_lov_property
What are the built-ins
used for processing rows?
Get_group_row_count(function)
Get_group_selection_count(function)
Get_group_selection(function)
Reset_group_selection(procedure)
Set_group_selection(procedure)
Unset_group_selection(procedure)
What are built-ins used
for processing rows?
GET_GROUP_ROW_COUNT(function)
GET_GROUP_SELECTION_COUNT(function)
GET_GROUP_SELECTION(function)
RESET_GROUP_SELECTION(procedure)
SET_GROUP_SELECTION(procedure)
UNSET_GROUP_SELECTION(procedure)
What are the built-in
used for getting cell values?
Get_group_char_cell (function)
Get_groupcell (function)
Get_group_number_cell (function)
What are the built-ins
used for getting cell values?
GET_GROUP_CHAR_CELL (function)
GET_GROUPCELL (function)
GET_GROUP_NUMBET_CELL (function)
At least how many set of
data must a data model have before a data model can be base on it?
Four
To execute row from being
displayed that still use column in the row which property can be used?
Format trigger.
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
What is the remove on
exit property?
For a modeless window, it
determines whether oracle forms hides the window automatically when the
operators navigates to an item in the another window.
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.
It generally occurs only when the operators modifies the first item in the
record, and after the operator attempts to navigate out of the item.
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.
What are built-ins
associated with timers?
find_timercreate_timerdelete_timer
What are the built-ins
used for finding object ID functions?
Find_group (function)
Find_column (function)
What are the built-ins
used for finding Object ID function?
FIND_GROUP (function)
FIND_COLUMN (function)
Any attempt to navigate
programmatically to disabled form in a call_form stack is allowed?
False
Use the Add_group_row
procedure to add a row to a static record group 1. True or false?
False
What third party tools
can be used with Oracle EBU/ RMAN? (For DBA)
The following Media
Management Software Vendors have integrated their media management software
packages with Oracle Recovery Manager and Oracle7 Enterprise Backup Utility.
The Media Management Vendors will provide first line technical support for the
integrated backup/recover solutions.
Veritas NetBackup
EMC Data Manager (EDM)
HP OMNIBack II
IBM's Tivoli Storage Manager - formerly ADSM
Legato Networker
ManageIT Backup and Recovery
Sterling Software's SAMS: Alexandria - formerly from Spectralogic
Sun Solstice Backup
Why and when should one
tune? (For DBA)
One of the biggest responsibilities of a DBA is to ensure that the Oracle
database is tuned properly. The Oracle RDBMS is highly tunable and allows the
database to be monitored and adjusted to increase its performance. One should
do performance tuning for the following reasons:
The speed of computing might be wasting valuable human time (users waiting for
response); Enable your system to keep-up with the speed business is conducted;
and Optimize hardware usage to save money (companies are spending millions on
hardware). Although this FAQ is not overly concerned with hardware issues, one
needs to remember than you cannot tune a Buick into a Ferrari.
How can a break order be
created on a column in an existing group? What are the various sub events a
mouse double click event involves?
By dragging the column outside the group.
What is the use of place
holder column? What are the various sub events a mouse double click event
involves?
A placeholder column is used to hold calculated values at a specified place
rather than allowing is to appear in the actual row where it has to appear.
What is the use of hidden
column? What are the various sub events a mouse double click event involves?
A hidden column is used to when a column has to embed into boilerplate text.
What
database aspects should be monitored? (For DBA)
One should implement a monitoring system to constantly monitor the following
aspects of a database. Writing custom scripts, implementing Oracle's Enterprise
Manager, or buying a third-party monitoring product can achieve this. If an
alarm is triggered, the system should automatically notify the DBA (e-mail,
page, etc.) to take appropriate action.
Infrastructure availability:
-
Is the
database up and responding to requests
-
Are the
listeners up and responding to requests
-
Are the
Oracle Names and LDAP Servers up and responding to requests
-
Are the
Web Listeners up and responding to requests
Things that can cause
service outages:
-
Is the
archive log destination filling up?
-
Objects
getting close to their max extents
-
User
and process limits reached
Things that can cause bad performance:
-
See
question "What tuning indicators can one use?”
Where the tuning effort
should be directed? (For DBA)
Consider the following areas for tuning. The order in which steps are listed
needs to be maintained to prevent tuning side effects. For example, it is no
good increasing the buffer cache if you can reduce I/O by rewriting a SQL
statement. Database Design (if it's not too late):
Poor system performance usually results from a poor database design. One should
generally normalize to the 3NF. Selective denormalization can provide valuable
performance improvements. When designing, always keep the "data access
path" in mind. Also look at proper data partitioning, data replication,
aggregation tables for decision support systems, etc.
Application Tuning:
Experience showed that approximately 80% of all Oracle system performance
problems are resolved by coding optimal SQL. Also consider proper scheduling of
batch tasks after peak working hours.
Memory Tuning:
Properly size your database buffers (shared pool, buffer cache, log buffer, etc.)
by looking at your buffer hit ratios. Pin large objects into memory to prevent
frequent reloads.
Disk I/O Tuning:
Database files needs to be properly sized and placed to provide maximum disk
subsystem throughput. Also look for frequent disk sorts, full table scans,
missing indexes, row chaining, data fragmentation, etc.
Eliminate Database Contention:
Study database locks, latches and wait events carefully and eliminate where
possible. Tune the Operating System:
Monitor and tune operating system CPU, I/O and memory utilization. For more
information, read the related Oracle FAQ dealing with your specific operating
system.
What are the various sub
events a mouse double click event involves? What are the various sub events a
mouse double click event involves?
Double clicking the mouse consists of the mouse down, mouse up, mouse click,
mouse down & mouse up events.
What are the default
parameter that appear at run time in the parameter screen? What are the various
sub events a mouse double click event involves?
Destype and Desname.
What are the built-ins
used for Creating and deleting groups?
CREATE-GROUP (function)
CREATE_GROUP_FROM_QUERY (function)
DELETE_GROUP (procedure)
What are different types
of canvas views?
Content canvas views
stacked canvas views
Horizontal toolbar
vertical toolbar.
What are the different
types of Delete details we can establish in Master-Details?
Cascade
Isolate
Non-isolate
What is relation between
the window and canvas views?
Canvas views are the back ground objects on which you place the interface items
(Text items), check boxes, radio groups etc.,) and boilerplate objects (boxes,
lines, images etc.,) that operators interact with us they run your form. Each
canvas views displayed in a window.
What is a User_exit?
Calls the user exit named in the user_exit_string. Invokes a 3Gl program by
name which has been properly linked into your current oracle forms executable.
How is it possible to
select generate a select set for the query in the query property sheet?
By using the tables/columns button and then specifying the table and the column
names.
How can values be passed
bet. precompiler exits & Oracle call interface?
By using the statement EXECIAFGET & EXECIAFPUT.
How can a square be drawn
in the layout editor of the report writer?
By using the rectangle tool while pressing the (Constraint) key.
How can a text file be
attached to a report while creating in the report writer?
By using the link file property in the layout boiler plate property sheet.
How can I pass a message
to the user from reports?
By using SRW.MESSAGE function.
Does one need to drop/
truncate objects before importing? (For DBA)
Before one import rows into already populated tables, one needs to truncate or
drop these tables to get rid of the old data. If not, the new data will be
appended to the existing tables. One must always DROP existing Sequences before
re-importing. If the sequences are not dropped, they will generate numbers
inconsistent with the rest of the database. Note: It is also advisable to drop
indexes before importing to speed up the import process. Indexes can easily be
recreated after the data was successfully imported.
How can a button be used
in a report to give a drill down facility?
By setting the action associated with button to Execute pl/sql option and using
the SRW.Run_report function.
Can one import/export
between different versions of Oracle? (For DBA)
Different versions of the import utility is upwards compatible. This means that
one can take an export file created from an old export version, and import it
using a later version of the import utility. This is quite an effective way of
upgrading a database from one release of Oracle to the next.
Oracle also ships some previous catexpX.sql scripts that can be executed as
user SYS enabling older imp/exp versions to work (for backwards compatibility).
For example, one can run $ORACLE_HOME/rdbms/admin/catexp7.sql on an Oracle 8
database to allow the Oracle 7.3 exp/imp utilities to run against an Oracle 8
database.
What are different types
of images?
Boiler plate imagesImage Items
Can one export to
multiple files?/ Can one beat the Unix 2 Gig limit? (For DBA)
From Oracle8i, the export utility supports multiple output files. This feature
enables large exports to be divided into files whose sizes will not exceed any
operating system limits (FILESIZE= parameter). When importing from multi-file
export you must provide the same filenames in the same sequence in the FILE=
parameter. Look at this example:
exp SCOTT/TIGER FILE=D:\F1.dmp,E:\F2.dmp FILESIZE=10m LOG=scott.log
Use the following technique if you use an Oracle version prior to 8i:
Create a compressed export on the fly. Depending on the type of data, you
probably can export up to 10 gigabytes to a single file. This example uses
gzip. It offers the best compression I know of, but you can also substitute it
with zip, compress or whatever.
# create a named pipe
mknod exp.pipe p
# read the pipe - output to zip file in the background
gzip <> scott.exp.gz &
# feed the pipe
exp userid=scott/tiger file=exp.pipe ...
What is bind reference
and how can it be created?
Bind reference are used to replace the single value in sql, pl/sql statements a
bind reference can be created using a (:) before a column or a parameter name.
How can one improve
Import/ Export performance? (For DBA)
EXPORT:
-
Set the
BUFFER parameter to a high value (e.g. 2M)
-
Set the
RECORDLENGTH parameter to a high value (e.g. 64K)
-
Stop
unnecessary applications to free-up resources for your job.
-
If you
run multiple export sessions, ensure they write to different physical disks.
-
DO NOT
export to an NFS mounted filesystem. It will take forever.
IMPORT:
-
Create
an index file so that you can create indexes AFTER you have imported data. Do
this by setting INDEXFILE to a filename and then import. No data will be
imported but a file containing index definitions will be created. You must edit
this file afterwards and supply the passwords for the schemas on all CONNECT
statements.
-
Place
the file to be imported on a separate physical disk from the oracle data files
-
Increase
DB_CACHE_SIZE (DB_BLOCK_BUFFERS prior to 9i) considerably in the init$SID.ora
file
-
Set the
LOG_BUFFER to a big value and restart oracle.
-
Stop
redo log archiving if it is running (ALTER DATABASE NOARCHIVELOG;)
-
Create
a BIG tablespace with a BIG rollback segment inside. Set all other rollback
segments offline (except the SYSTEM rollback segment of course). The rollback
segment must be as big as your biggest table (I think?)
-
Use
COMMIT=N in the import parameter file if you can afford it
-
Use
ANALYZE=N in the import parameter file to avoid time consuming ANALYZE
statements
-
Remember
to run the index file previously created
Give the sequence of
execution of the various report triggers?
Before form, After form , Before report, Between page, After report.
What are the common
Import/ Export problems? (For DBA)
ORA-00001: Unique constraint (...) violated - You are importing duplicate rows.
Use IGNORE=NO to skip tables that already exist (imp will give an error if the
object is re-created).
ORA-01555: Snapshot too old - Ask your users to STOP working while you are
exporting or use parameter CONSISTENT=NO
ORA-01562: Failed to extend rollback segment - Create bigger rollback segments
or set parameter COMMIT=Y while importing
IMP-00015: Statement failed ... object already exists... - Use the IGNORE=Y
import parameter to ignore these errors, but be careful as you might end up
with duplicate rows.
Why is it preferable to
create a fewer no. of queries in the data model?
Because for each query, report has to open a separate cursor and has to rebind,
execute and fetch data.
Where is the external
query executed at the client or the server?
At the server.
Where is a procedure
return in an external pl/sql library executed at the client or at the server?
At the client.
What is coordination
Event?
Any event that makes a different record in the master block the current record
is a coordination causing event.
What is the difference
between OLE Server & Ole Container?
An Ole server application creates ole Objects that are embedded or linked in
ole Containers ex. Ole servers are ms_word & ms_excel. OLE containers provide
a place to store, display and manipulate objects that are created by ole server
applications. Ex. oracle forms is an example of an ole Container.
What is an object group?
An object group is a
container for a group of objects; you define an object group when you want to
package related objects, so that you copy or reference them in other modules.
What is an LOV?
An LOV is a scrollable popup window that provides the operator with either a
single or multi column selection list.
At what point of report
execution is the before Report trigger fired?
After the query is executed but before the report is executed and the records
are displayed.
What are the built -ins
used for modifying a groups structure?
ADD-GROUP_COLUMN (function)
ADD_GROUP_ROW (procedure)
DELETE_GROUP_ROW (procedure)
What is user exit used
for?
A way in which to pass control (and possibly arguments) form Oracle report to
another Oracle products of 3 GL and then return control (and) back to Oracle
reports.
What is the User-Named
Editor?
A user named editor has the same text editing functionality as the default
editor, but, because it is a named object, you can specify editor attributes
such as windows display size, position, and title.
My database was
terminated while in BACKUP MODE, do I need to recover? (For DBA)
If a database was terminated while one of its tablespaces was in BACKUP MODE
(ALTER TABLESPACE xyz BEGIN BACKUP ;), it will tell you that media recovery is
required when you try to restart the database. The DBA is then required to
recover the database and apply all archived logs to the database. However, from
Oracle7.2, you can simply take the individual datafiles out of backup mode and
restart the database.
ALTER DATABASE DATAFILE '/path/filename' END BACKUP;
One can select from V$BACKUP to see which datafiles are in backup mode. This
normally saves a significant amount of database down time
From Oracle9i onwards, the following command can be used to take all of the
datafiles out of hot backup mode:
ALTER DATABASE END BACKUP;
The above commands need to be issued when the database is mounted.
What is a Static Record
Group?
A static record group is not associated with a query, rather, you define its
structure and row values at design time, and they remain fixed at runtime.
What is a record group?
A record group is an internal Oracle Forms that structure that has a column/row
framework similar to a database table. However, unlike database tables, record
groups are separate objects that belong to the form module which they are
defined.
My database is down and I
cannot restore. What now? (For DBA)
Recovery without any backup is normally not supported, however, Oracle
Consulting can sometimes extract data from an offline database using a utility
called DUL (Disk UnLoad). This utility reads data in the data files and unloads
it into SQL*Loader or export dump files. DUL does not care about rollback
segments, corrupted blocks, etc, and can thus not guarantee that the data is
not logically corrupt. It is intended as an absolute last resort and will most
likely cost your company a lot of money!!!
I've lost my REDOLOG
files, how can I get my DB back? (For DBA)
The following INIT.ORA parameter may be required if your current redo logs are
corrupted or blown away. Caution is advised when enabling this parameter as you
might end-up losing your entire database. Please contact Oracle Support before
using it. _allow_resetlogs_corruption = true
What is a property
clause?
A property clause is a named object that contains a list of properties and
their settings. Once you create a property clause you can base other object on
it. An object based on a property can inherit the setting of any property in
the clause that makes sense for that object.
What is a physical page? &
what is a logical page?
A physical page is a size of a page. That is output by the printer. The logical
page is the size of one page of the actual report as seen in the Previewer.
I've lost some Rollback
Segments, how can I get my DB back? (For DBA)
Re-start your database with the following INIT.ORA parameter if one of your
rollback segments is corrupted. You can then drop the corrupted rollback
segments and create it from scratch.
Caution is advised when enabling this parameter, as uncommitted transactions
will be marked as committed. One can very well end up with lost or inconsistent
data!!! Please contact Oracle Support before using it.
_Corrupted_rollback_segments = (rbs01, rbs01, rbs03, rbs04)
What are the differences
between EBU and RMAN? (For DBA)
Enterprise Backup Utility (EBU) is a functionally rich, high performance
interface for backing up Oracle7 databases. It is sometimes referred to as OEBU
for Oracle Enterprise Backup Utility. The Oracle Recovery Manager (RMAN)
utility that ships with Oracle8 and above is similar to Oracle7's EBU utility.
However, there is no direct upgrade path from EBU to RMAN.
How does one create a
RMAN recovery catalog? (For DBA)
Start by creating a database schema (usually called rman). Assign an
appropriate tablespace to it and grant it the recovery_catalog_owner role. Look
at this example:
sqlplus sys
SQL> create user rman identified by rman;
SQL> alter user rman default
tablespace tools temporary tablespace temp;
SQL> alter user rman quota unlimited
on tools;
SQL> grant connect, resource,
recovery_catalog_owner to rman;
SQL> exit;
Next, log in to rman and create the catalog schema. Prior to Oracle 8i this was
done by running the catrman.sql script. rman catalog rman/rman
RMAN> create catalog tablespace tools;
RMAN> exit;
You can now continue by registering your databases in the catalog. Look at this
example:
roman catalog roman/roman target backdba/backdba
RMAN> register database;
How can a group in a
cross products be visually distinguished from a group that does not form a cross
product?
A group that forms part of a cross product will have a thicker border.
What is the frame &
repeating frame?
A frame is a holder for a group of fields. A repeating frame is used to display
a set of records when the no. of records that are to displayed is not known
before.
What is a combo box?
A combo box style list item combines the features found in list and text item.
Unlike the pop list or the text list style list items, the combo box style list
item will both display fixed values and accept one operator entered value.
What are three panes that
appear in the run time pl/sql interpreter?
1. Source pane.
2. Interpreter pane.
3. Navigator pane.
What are the two panes
that Appear in the design time pl/sql interpreter?
1. Source pane.
2. Interpreter pane
What are the two ways by
which data can be generated for a parameters list of values?
1. Using static values.
2. Writing select statement.
What are the various
methods of performing a calculation in a report?
1. Perform the calculation in the SQL statements itself.
2. Use a calculated / summary column in the data model.
What are the default
extensions of the files created by menu module?
.mmb,
.mmx
What are the default
extensions of the files created by forms modules?
.fmb - form module binary
.fmx - form module executable
To display the page no.
for each page on a report what would be the source & logical page no. or &
of physical page no.?
& physical page no.
It is possible to use raw
devices as data files and what is the advantages over file. System files?
Yes. The advantages over
file system files. I/O will be improved because Oracle is bye-passing the kernel
which writing into disk. Disk Corruption will be very less.
What are disadvantages of
having raw devices?
We should depend on export/import utility for backup/recovery (fully reliable).
The tar command cannot be used for physical file backup, instead we can use dd
command which is less flexible and has limited recoveries.
What is the significance
of having storage clause?
We can plan the storage for a table as how much initial extents are required,
how much can be extended next, how much % should leave free for managing row
updations etc.
What is the use of
INCTYPE option in EXP command?
Type export should be performed COMPLETE, CUMULATIVE, and INCREMENTAL. List the
sequence of events when a large transaction that exceeds beyond its optimal
value when an entry wraps and causes the rollback segment to expand into a notion
completes will be written.
What is the use of FILE
option in IMP command?
The name of the file from which import should be performed.
What is a Shared SQL
pool?
The data dictionary cache is stored in an area in SGA called the Shared SQL
Pool. This will allow sharing of parsed SQL statements among concurrent users.
What is hot backup and
how it can be taken?
Taking backup of archive log files when database is open. For this the
ARCHIVELOG mode should be enabled. The following files need to be backed up.
All data files. All Archive log, redo log files. All control files.
