Is "SET TRANSACTION USE ROLLBACK SEGMENT" only a hint
I have two users, one makes some inserts in a table.
The other makes a select which visits many rows.
I have a big rollback-segment.
To ensure, both users use this rollback-segment I created a logon-trigger:
CREATE OR REPLACE TRIGGER a_logon AFTER LOGON
WHEN ( USER IN ( 'SCOTT', 'BOB' ) )
SET TRANSACTION USE ROLLBACK SEGMENT rbs_big;
But I still get "snapshot to old" messages from the select, which contains the name off an other rollback-segment in the message.
The trigger really fires, i tested it by adding an insert-statement to a log-table.
What`s wrong ?
The set transaction use rollback segment lasts only until you commit or rollback first time and all other transactions in that session will not be forced to that rbs anymore. Other possible solution could be that other users are accessing same tables / updating them so those sessions can't keep the read consistent image available anymore for your sessions.View 2 Replies