-
Can a view based on another view
sivaraju.sateesh
- Apr 6th, 2009
Yes a view can be based on another view. For example data dictionary views can be used to create another view in order to improve better access.
soccer_champ
- Jun 18th, 2005
Yes, a view can be based on another view.
-
What is a synonym
sivaraju.sateesh
- Apr 6th, 2009
Synonym is a alias name for an Oracle object. It can be simplified names to access the objects. Example of Synonym and how it is useful Employee is a table is HR Schema A user wants to access the...
waseemvnb
- Nov 12th, 2007
It is just like Aliasing .. ie giving some name in order to specicifically distinguish it....In other words to simplify the names of tables , column names etc it is used.. Suppose i have a column name...
-
What is a private synonym
Dan
- Jul 9th, 2005
To create a private synonym in your own schema, you must have CREATE SYNONYM system privilege. To create a private synonym in another user's schema, you must have CREATE ANY SYNONYM system ...
-
What is a public synonym
sivaraju.sateesh
- Apr 7th, 2009
Public synonym is a synonym which may not resodes in the owner schema.but it works as a same. to create public synonym we need special privileges
soccer_champ
- Jun 18th, 2005
A public synonym is owned by the special user group named PUBLIC and every user in a database can access it. In case of doubt, contact me : bobby_1020@hotmail.com
-
Limit and Default size of Tablespace
Can we create as many tablespace as we require. What is the limit? What is the default size of tablespace? (System and User tablespace). Mention name of some tablespace.
-
Oracle Datafiles limit
How do you control No. of Datafiles one can have in an Oracle Database.
olilogu
- May 11th, 2009
At creation time you can set up the maximun numer of datafiles.CREATE DATABASE .....MAXDATAFILES 500If you want to check it:select * from V$CONTROLFILE_RECORD_SECTION where type ='DATAFILE';If you want to increase it, you have to recreate control file.
-
Oracle memory segments
How do you see how many memory segments are acquired by Oracle Instance.
olilogu
- May 11th, 2009
Check on x$bh it show you what objects are in the buffer.Try this query;SELECT /*+ ordered use_hash(o) use_hash(bh) */ bp.NAME BUFFER_POOL, ...
-
Recover corrupted database
If the entire disk is corrupted how will you recover the database and what are the steps to recover the database?
m4k4v3l1
- Jul 1st, 2009
Things Useful For Complete Recovery :1- Last Valid Backup2- Dump Files3- Archive Logs- If You Have a Valid Backup on Another Disk Rather Than The Damaged One , You Can Recover The Database till The Ti...
kalpeshbanokar
- Jul 24th, 2008
Succesful backup is possible iff there is "Archive Mode" is on.that is database is in Archive Mode.and if it's offthen there are only 99.9% chancesthroughGroup1 or Group2 of Online Redo log files.
-
What is a database instance and Explain
imran44
- Jul 10th, 2009
SGA+Background Process = InstanceAs soon as user process starts and server process takes control from user process, instance created with help of background processes and most important background pro...
cmanne
- Jan 4th, 2006
An Oracle instance is a combination of background processes and memory structures (SGA)
-
What is a redo log
imran44
- Jul 10th, 2009
At the time of database creation 2 redo log files are created, these redo log files act in circular fashion, when log switch occur, redo log file will dump its contents in archived log destination, an...
nagabhushan reddy
- Feb 8th, 2006
Redo log file contains data which changes made to the database.it is used for recovery purpose.
-
Why in 10G, when you use real time apply feature in conjunction with Maximum Protection, you can achive zero data loss, but not zero database downtime??
santosh Panigrahi
- Jul 12th, 2009
The 2 basic feature of Oracle 10g makes database Maximum protection and Zero downtime (1) Undo Retention Guarantee.(2) Stand by server compatibility.
senthilora
- Sep 24th, 2007
Maximum Protection mode - guarantees Zero data loss. But it can not guarantee Zero down time.Any transaction happening in Primary Database has to be propagated and commited in Standby Datab...
-
How to find which tablespace belongs to which datafile ?
ravichandiran
- Nov 16th, 2007
run this query in the sql promptsql> select tablespace_name,file_name from dba_data_files;
-
How do you find wheather the instance was started with pfile or spfile
Thhere are 3 different ways :-1) SELECT name, value FROM v$parameter WHERE name = 'spfile'; //This query will return NULL if you are using PFILE2) SHOW PARAMETER spfile // This query will returns NULL in the value column if you are using pfile and not spfile3) SELECT COUNT(*) FROM v$spparameter WHERE value IS NOT NULL; // if the count is non-zero then the instance is using a spfile, and if the count...
-
How to Estimate the size of Tablespace???
cmanne
- Sep 2nd, 2009
During the design phase of database, The tablesapce size is estimated by calculating the size of typical row of various tables that are going to reside in that tablespace multiplied by the number of e...
cmanne
- Sep 2nd, 2009
Select tablespace_name, sum(bytes)/1024/1024fromdba_data_filesgroup by tablespace_nameorder by tablespace_name;
-
DML operations on standby database
Can you perform DML operations when the standby database is in read only in Standby Database?
cmanne
- Sep 2nd, 2009
In a nutshell, One can do SELECTS only on a Physical/Logical Standby database. The basic principle behind Oracle Standby database is to provide protection against media failures. So no DMLs are allowe...
aravindhreturns
- Jul 7th, 2009
I agree with omelkoz, But I need to add a small point here. Specifying STANDBY is to to prevent all users other than SYS from making DML and DDL changes to any table or sequence being maintained through SQL apply operations. Not everybody can execute statements on a standby. :)
-
Corrupted Rollback Segment
How will you rectify if one of the rollback segments gets corrupted
-
How to find how many database reside in Oracle server in query?
cmanne
- Sep 2nd, 2009
1. Check the oratab file to get the list of databases on a server.Caveat: If the database is created manually, then the oratab won't updated automatically which should be done manually as oratab i...
Krishna Miryala
- Apr 15th, 2007
$ ps -eaf|grep pmon
-
Naming exported files
When exporting using filesize parameter, if three files is generated. How the Oracle name this three files?
jp1985verma
- Oct 22nd, 2009
When Export reaches the value you have specified for the maximum FILESIZE, Export stops writing to the current file, opens another export file with the next name specified by the FILE parameter, and c...
-
Dump Destination
What is dump destination? What are bdump, cdump and udump? Explain in detail.
anurag2202
- Oct 30th, 2009
The dump destination is: Oracle_home/admin/<SID>The UDUMP specifies user dump directory where all the user related information is stored in the form of trace file.The BDUMP specifies background ...
aravindhreturns
- Jul 6th, 2009
UDUMP is specifying the user dump directory where all user error logs (trace files) will be placed.BDUMP is specifying the background dump directory where all database error logs (trace files) will be...
-
Oracle Compress Parameter
My database size is 100GB. I am using compress parameter. Will my database size reduce, remain same, Increase. What will Happen.
krishna miryala
- Nov 5th, 2009
When "Y",export will mark the table to be loaded as one extent for the import utility. This option will use only if you want to do import. export size will not change if we use compress=y.
Oracle DBA Interview Questions
Ans