Re: Usage of the dbms_stats.gather_database_stats() procedure

>
>  Steve,
>
 I've just become aware of an instance that has 130 schemas with a total of
> 15,000 tables, 12,700 of which have no optimizer statistics. Even though
> things run relatively well without the stats we are sometimes bitten by poor
> performance without warning and have to compute stats as a fix
>
I'm confused. So you have no statistics or just some?
   My concern is that this could easily become a people problem. If most
queries are running fine, then when you apply statistics some queries will
run worse. Maybe much worse. Then whose head will they be looking for? Been
there.
    Here is the way I would approach it.
 1. Associate schemas with groups of users and see if you can roll out
statistics gradually.
 2. Configure a test database, and generate statistics.
 3. Meet with representatives of each group of users, and explain what you
intend to do. Ask that they test their critcal queries.
 4. Announce a schedule of implementation for each group.
With luck you might survive.

Dennis Williams

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