Re: Comparison of DB2 and Oracle?
From: Serge Rielau <srielau_at_ca.ibm.com>
Date: Thu, 21 Oct 2004 09:25:44 -0400
Message-ID: <2tprmrF23getiU1_at_uni-berlin.de>
Date: Thu, 21 Oct 2004 09:25:44 -0400
Message-ID: <2tprmrF23getiU1_at_uni-berlin.de>
OK, here is the deal:
Does that answer the comment?
Cheers
When you execute a dynamic statement which depends on table T.
DB2 will hold a usage lock on T until the end of the transaction.
So noone will be able to alter T (in a non-trivial way) until this
transaction is over.
An alternate design would be to release the lock after usage.
However in the interest of keeping the cache fast the capturing of locks
needs to be minimized. Schema evolution is considered a much rarer (more
rare??) event than cache-hits
Serge
Received on Thu Oct 21 2004 - 15:25:44 CEST