Re: Telling When Statistics Present
Date: 1995/10/24
Message-ID: <parkerr.41.0009EAAB_at_logica.com>#1/1
In article <46gp7g$3tn_at_lastactionhero.rs.itd.umich.edu> Dave McLaughlin <davemc_at_umich.edu> writes:
>We are running RDBMS 7.1.4 on AIX and Server Manager 2.0.4 on Windows.
>We just upgraded the server from 7.0, and I made what appears to be a
>startling discovery. We have specified optimization_mode "choose" in
>init.ora, and we believed that we were using the rule-based optimizer
>most of the time. However, over half of our tables have statisitics
>present according to Server Manager (the "optimizer" tab in the "schema"
>file). We have no idea how this could be. Could Server Manager be
>wrong? Are there any likely ways of generating object statistics other
>than explicit use of the ANALYZE command? Are we really using the
>cost-based optimizer with these tables?
>TIA
>Dave McLaughlin
>University of Michigan
You can tell when you are using the cost based optimizer - the whole system
slows to a crawl !! :-(
I made the mistake of doing an ANALYZE TABLE on some tables on one of my live
systems. The phone rang hot with complaints until I realised what was
happening and deleted the stats. Leason learned the hard way.
Robin.