Hi Mary , 5th May 2001 16:05 hrs chennai

What i would suggest you is always do a thorough Investigation(Tuning) the RBS with the avilable means in oracle.

I.Using v$ views

II.Using Oracle OEM.Tuning packs.

III.Running UTLBSTAT and UTLESTAT

===Mehod I====
The main area you have to see is the RBS header contention where all the problems lies.

A simple formula to work on is .

>SELECT SUM(WAITS)*100/SUM(GETS) "RATIO",SUM(WAITS) "WAITS",SUM(GETS) "GETS" FROM V$ROLLSTAT;

If the ratio of the sum of WAITS to Sum of GETS should be less than 5%.

If not then try to create more RBS.

====Method II===

The number of waits for any class should be less than 1% of the total number of requests.

>SELECT CLASS,COUNT FROM V$WAITSTAT WHERE CLASS LIKE '%undo%';

>SELECT SUM(VALUE) FROM V$SYSSTAT WHERE NAME='consistent gets';

Take the statistics and compare the values.As i mentioned above if the % is above 1% try to create more RBS.

===Method III====

Always during IMPORT set COMMIT=Y.Size the set of rows with BUFFER_SIZE

During Export set CONSISTENT=N

SQL LOADER set the COMMIT intervals with ROWS keyword.

Cheers

Padmam

==============

The rest as said by HALO.

Cheers

Padmam