kunal1017

 Profile Answers by kunal1017 Questions by kunal1017

• Jan 10th, 2008

HiBase tables are made when the database is created and these tables are stored in data dictionary. these base tables contains the information related to the database.? these tables are own by sys.th...

Answer Question  Select Best Answer

What is the difference between Cloning and Standby databases?

rajendra_thanekar

 Profile Answers by rajendra_thanekar Questions by rajendra_thanekar

• Jan 2nd, 2008

Cloning is nothing but the copy of your database which can be open in read write mode. The standby database is also a copy of your database which is in standby mode and which is made in sink with prod...

Answer Question  Select Best Answer

Hi, I've recently commissioned a hosted system from a developer who has recommended using J2EE and Oracle. Their J2EE system is quite slick and works very well in preproduction. It uses annotations to generate the Oracle tables on the fly during deployment. On examination of the table structures that it's generated though, it's defaulted all of the VARCHAR2 definitions to 255 characters. On asking...

kailasTile

 Profile Answers by kailasTile Questions by kailasTile

• Dec 18th, 2007

Changing VARCHAR2(255) to precise required width is good table design. Though it will not improve performance as such.

Answer Question  Select Best Answer

kailasTile

 Profile Answers by kailasTile Questions by kailasTile

• Dec 17th, 2007

It depends on your requirement, if you want no of users around 300 then you can still achieve that by keeping PGA parameters low. If you are looking for number of users 1000 or even more, you need to go for shared server mode. 

Answer Question  Select Best Answer

How to assign an index tablespace for a database permanently, so that whatever indexes we are creating in the database, should automatically goes to that tablespace i.e. we neednot supply the tablespace name during index creation.

kailasTile

 Profile Answers by kailasTile Questions by kailasTile

• Dec 17th, 2007

There is no such provision in oracle to have default index tablespace. Workaround is- you can have a job which will scan for indexes in other tablespaces and rebuild into desired one.

Answer Question  Select Best Answer

pradeesh04

 Profile Answers by pradeesh04 Questions by pradeesh04

• Dec 7th, 2007

Oracle Net Services use a centralized directory server as one of the primary methods for storage of  connect identifiers. Clients configured directory usage can use the connect identifiers in the...

singhsarabjit

 Profile Answers by singhsarabjit Questions by singhsarabjit

• Dec 6th, 2007

oid

Answer Question  Select Best Answer

dinesh1909

 Profile Answers by dinesh1909 Questions by dinesh1909

• Nov 19th, 2007

Consider 8K block size. The total bytes 8 x 1024 = 8196 bytesEach block requires approximately 117 bytes for the header. Please note that the header size varies depending upon the block size. The tota...

C.Ramesh

• Nov 16th, 2007

PCT USERD -  The Percentage of Minimum space user for insertion of New Row data. The value determines when the block gets into the FREELISTS structurePCTFREE - The Percentage of Space reserved for future updation of existing dataC.Ramesh

Answer Question  Select Best Answer

 Two  processes wating to update the rows of a table which are locked by the other process then deadlock arises. In  a  database  environment  this will often happen because of not issuing proper  row  lock  commands. Poor design of front-end application may cause this situation and the performance of server will reduce drastically. These locks...

msabuu

 Profile Answers by msabuu Questions by msabuu

• Nov 6th, 2007

Oracle automatically detect deadlock , but not occar

Answer Question  Select Best Answer

Latches are low level serialization mechanisms used to protect shared data structures in the SGA. The implementation of latches is operating system dependent, particularly in regard to whether a process will wait for a latch and for how long.A latch is a type of a lock that can be very quickly acquired and freed. Latches are typically used to prevent more than one process from executing the same piece...

manoj seemar

• Nov 2nd, 2007

Latches are simple, low-level serialization mechanisms to protect shared data structures in the system global area (SGA). For example, latches protect the list of users currently accessing the databas...

Answer Question  Select Best Answer

Enqueues are another type of locking mechanism used in Oracle. An enqueue is a more sophisticated mechanism which permits several concurrent processes to have varying degree of sharing of "known" resources. Any object which can be concurrently used, can be protected with enqueues. A good example is of locks on tables. We allow varying levels of sharing on tables e.g. two processes can lock a table...

manoj seemar

• Nov 2nd, 2007

An enqueue is a sophisticated locking mechanism that permits several concurrent processes to share known resources to varying degrees. Any object that can be used concurrently can be protected with en...

Answer Question  Select Best Answer

The primary functional difference between logical and physical standby database setups is that logical standby permits you to add additional objects (tables, indexes, etc) to the database, while physical standby is always an exact structural duplicate of the master database. The downside, though, is that logical standby is based on newer technologies (logical standby is new in Oracle 9.2) and tends...

Ashu Shukla

• Oct 29th, 2007

A physical or logical standby database is a database replica created from a backup of a primary database. A physical standby database is physically identical to the primary database on a block-fo...

santhosh

• Jun 26th, 2006

Physical Standby - acheived by copying the archivle log filesLogical Standby - makes the dml statements using archivelogs generated and applies to the secondary database

Answer Question  Select Best Answer

Ajwat Hasan

• Oct 10th, 2007

Often the word "lock" is synonymous to enqueue. In this document, "enqueue" will be used for the locking mechanism that you can find in V$LOCK. "locking" will be used whe...

Answer Question  Select Best Answer

Whenever commit,checkpoint or redolog buffer is 1/3rd full

Jayesh Patel

• Oct 9th, 2007

LGWR writes:1) COMMIT/ ROLLBACK2) 1 MB of large transaction3) Before DBWR writes4) 1/3 of REDO LOG is full5) time out occurs6) Check Point encounters

SALIH

• Dec 15th, 2005

1.COMMIT or ROLLABCK2.time out occurs (3 secs)3 1/3 of log is full4. 1 mb of redo5. Checkpoint occurs

Answer Question  Select Best Answer

 Group  of  tables  physically  stored  together  because  they share common columns and are often used together is called Cluster.

parthokonar1

 Profile Answers by parthokonar1 Questions by parthokonar1

• Sep 28th, 2007

Yes that is true, For creating cluster we first create the cluster via index/hash, then we all the tables in the cluster.

Answer Question  Select Best Answer

Mohammed Abdul Afroze

• Sep 28th, 2007

An Extent is a set of contignous data blocks obtain in a single allocation and used to store specific type of information.

Yoh

• Jul 30th, 2006

Extends are a collection of data blocks

Answer Question  Select Best Answer

senthilora

• Sep 24th, 2007

And.. I think, the question is about Data Migration - something related to migrating data between different databases.I have done using different tools like Data Junction, Informatica, even PL/SQL and SQL Loader.

Jacob Asirwadam SK, Biguvu

• May 21st, 2007

RAC stands for Real Application Cluster. In previous versions, it is known as PARALLEL SERVER. RAC is a mechanism that allows multiple instances (on different hosts/nodes) to access the same database....

Answer Question  Select Best Answer

senthilora

• Sep 24th, 2007

There are many ways to do that.? Following is the one of the ways I would prefer as I do it usually.You can achieve this by having a small Unix Scripting / Windows Shell Scripting?/ any other script...

Answer Question  Select Best Answer

senthilora

 Profile Answers by senthilora Questions by senthilora

• Sep 24th, 2007

1. set SHARED_SERVERS=(more than 1) in init.ora2. make changes in tnsnames.ora file to get the connection with DISPATHERS rather than dedicated servers

SALIH

• Dec 15th, 2005

Use DBCA toolYou will get the option to select shared server mode.

Answer Question  Select Best Answer

senthilora

 Profile Answers by senthilora Questions by senthilora

• Sep 24th, 2007

And.. It does not store any data value in it unlike normal index do.Queries will not get benefitted. This can be used only for analysis.

Varun

• Sep 11th, 2005

1. These are permanent and continue to exist unless we drop them.2. Their creation will not affect existing and new sessions. Only sessions marked for Virtual Index usage will become aware of their ex...

Answer Question  Select Best Answer

senthilora

 Profile Answers by senthilora Questions by senthilora

• Sep 24th, 2007

Another suggestion could be: Find the Master Table(s) of the given table and export / import them all.

balakrishna

• May 28th, 2006

If u want to import the table just say constraints=n the movement table got imported then u create constriant on that tables.

Answer Question  Select Best Answer