Rollback Segment and how to use the statement "Set transaction use rollback segment ???"

Hi guys,

        I am trying to use sql statement "set transaction use rollback segment bigroll" to set that Oracle will set the "bigroll" (a much bigger rollback segment in size) to do the analyze on some tables. However, I got this error message:

analyze table episodes estimate statistics sample 50 percent *
ERROR at line 1:
ORA-01555: snapshot too old: rollback segment number 21 with name "R20" too small

while the sql statements used are liike this:

set transaction use rollback segment bigroll; analyze table episodes estimate statistics sample 50 percent;

but "bigroll" is not R20. How did that happen? Can someone explain to me how rollback segments work?

please either post your reply here or send email to me using mleung_at_earthlink.net or mleung_at_intelus.com

thanks in advance

Michael Leung

WindyCloud
7k_at_gamestats.com

Realms of the Kingdoms, http://7k.gamestats.com Received on Sat Aug 28 1999 - 07:46:59 CDT