1.How would you go about generating an EXPLAIN
plan?
Answer:
Create
a plan table with utlxplan.sql.
Use
the explain plan set statement_id = 'tst1' into plan_table for a SQL statement
Look
at the explain plan with utlxplp.sql or utlxpls.sql
2.Explain steps involved in Migration from Oracle
9.0.1 to 9.2.0.6 [out dated :-)]
Answer:
1.
Shutdown 9.0.1 database
2. Apply software patch tonew/old ORACLE_HOME
3. Change ORACLE_HOME to point to new 9.2.0.6 binaries
4. STARTUP MIGRATE
5. @ORACLE_HOME/rdbms/admin/catpatch.sql
6. @ORACLE_HOME/rdbms/admin/utlrp.sql
7. Change init.ora parameter COMPATIBLE =
9.2.0.6
8. Shutdown and startup normal
3.Name five top 9I init.ora parameters affecting
performance
Answer:
1.
CURSOR_SHARING
2. DB_CACHE_SIZE
3. PGA_AGGREGATE_TARGET
4. WORKAREA_SIZE_POLICY
5. DB_16K_CACHE_SIZE, DB_8K_CACHE_SIZE, DB_2K_CACHE_SIZE
4.How do you recover database when you lost all of
your control files?
Answer:
In
case of loss of loss of all control files, you can still recover database as
long as you have all
archivelog files. You can issue following command to recover the database.
RECOVER DATABASE USING BACKUP CONTROLFILES UNTIL CANCEL;
Apply all archivelog files
ALTER DATABASE OPEN RESETLOGS;
SHUTDOWN IMMEDIATE;
Backup database (COLD)
STARTUP;
5.Explain different protection mode in DATAGURD
Answer:
MAXIMUM
PROTECTION
MAXIMUM AVAILIBILITY
MAXIMUM PERFORMANCE
6.Which dynamic performance view DBA can query to
see who deleted data from a
particular table sometime back?
Answer:
V$LOGMNR_CONTENTS
7.What is the quickest way to clone a database
give your backup is done via RMAN?
Answer:
Using
RMAN command DUPLICATE DATABASE
8.What
is the pre-req for RAC implementation ?
Answer:
a)Server
IP configuration
b)INstallation
steps on cluster and Oracle home
c)Creation
of database
9.What
is OCR and voting disk ?
Oracle
Cluster registry (oCR )
OCR
manages Oracle Clusterware and Oracle RAC database configuration information
OLR
resides on every node in the cluster and manages Oracle Clusterware
configuration information for each particular node
Voting
disks manage information about node membership. Each voting disk must be
accessible by all nodes in the cluster for nodes to be members of the cluster
10.Name 5 init.ora parameters that needs to set in
Primary database for DataGuard
configuration
Answer:
LOG_ARCHIVE_DEST_2
LOG_ARCHIVE_DEST_2_STATE
FAL_CLIENT
FAL_SERVER
STANDBY_ARCHIVE_DEST
STANDBY_FILE_MANAGEMENT
11.What is the use of FORCE LOGGING option?
Answer:
By
setting FORCE LOGGING to TRUE, all transactions will generate REDO. This is
used for Data Guard,
so no
data will be missed (i.e. transactions that were run with NOLOGGING option) in
Standby database.
12.Is it possible to configure primary server and
stand by server on different OS?
Answer:
Answer
for this questions is NO. Standby database must be on same version of database
and same
version
of Operating system.
13.Is it possible to use raw devices as data files
and what is the advantages over
filesystem files ?
Answer:
Yes.
The
advantages over file system files:
I/O
will be improved because Oracle will bypass the OS. Disk Corruption will be very
less.
14.What are disadvantages of having raw devices?
Answer:
We
have to depend on export/import utility for backup/recovery
The
tar command cannot be used for physical file backup, instead we have to use dd
command which is
less
flexible and has limited recoveries.
15.A DBA had to remove some Archivelogs to free up
space in filesystem. Now when
the
RMAN job starts to backup Archivelogs, it complains about missing Archivelogs
that were deleted by
DBA.
To resolve the issue and continue backing up remainder of Archivelogs, which
RMAN command
can
be used so it won't complain about missing Archivelogs.
Answer:
Crosscheck
command
16.List
command for voting disk
Answer:
$CRSCTL
CSS QUERY VOTEDISK
17.Patching
RAC environments .Types of patching Rolling patching .How do you apply patching
to RAC cluster.
Answer:
Shutting
down the instance in local instance using opatch auto by rolling patching
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