Hi

orcale, have undo tablespace which provide old image user and avoid lock's for the readers ?

DB2 stores transactions committed and uncommitted data in log files, nothing like old image, until db2 9.7 which has currently committed option which also stores the old image in logs which allow the user to read this.

Please correct me.

regds
Paul

Hi,

i don't know the exact details, but you are right.
DB2 keeps the old versions in the Transaction-Logs.

SQL-Server uses tempdb for it's snapshot-isolation.