RE: Concurrent transaction per rollback segment.

Jaffar

>Can anyone tell me, that one rollback segment can handle how many
>concurrent transactions? I know that oracle keeps the transaction
>table in the header block of segment's.

Each entry (slot) of the transaction table manages a single transaction. Therefore the \ number of entries is the maximum number of transactions. This is a value in the 20-200 \ range (about 50% of the block is used for the transaction table and each slot is about 40 \ bytes, see V$TYPES for more info...).

But, be careful, for good performance you should, usually, never have so much concurrent \ transactions in a single undo segment.  

>I have taken the system dump of this block, but, couldn't understand
>where to see for concurrent transaction value in the dump file.
>Can anyone have any idea how to find out the value?

Active transactions have state=10 in the transaction table.

If you want to know the number of active transactions at a given time you can query \ V$TRANSACTION (group by XIDUSN) as well.

HTH
Chris

--
http://www.freelists.org/webpage/oracle-l