Re: cursor_sharing setting
Date: Mon, 10 Feb 2020 13:16:30 -0600
Message-ID: <CAPTPB11Rtj2pxn_GbFj=j6xPz8ibXGJv7R0GVKyx=uY+nFzoug_at_mail.gmail.com>
Thanks everyone.
Andrew:
"Bind varaibles for a partition key should inhibit from partion stats being
used on parsing." I think the optimizer may not know to use indexes or not,
etc. which applies even to an OLTP system. I remember reading about those
things in Christian's TOP book. (Thank you Christian if you are reading
this thread, a great book).
what does that parameter do? I couldnt get any good results searching. Does
it let the optimizer peek at bind variable values once a while?
On Mon, Feb 10, 2020 at 11:24 AM Andrew Kerber <andrew.kerber_at_gmail.com>
wrote:
> What is the _optim_peek_user_binds setting?
NAME VALUE DEFLT
--------------------------------------------- ------------------------
------------------------
_optim_peek_user_binds TRUE TRUE
>
> In any case, if the warehouse has been running for some time without
> serious problem, you probably dont want to change that setting without
> understanding why it was set the way it was to begin with. Of course, the
> answer is likely to be that it was set that way 10 years ago in oracle 9i
> and never changed it, but it is still not something to change without
> testing.
>
> On Mon, Feb 10, 2020 at 11:13 AM Mladen Gogala <gogala.mladen_at_gmail.com>
> wrote:
>
>> I would not set it anywhere. CS = FORCE is a source of many optimizer
>> bugs and is only recommended in case of an emergency, where one needs to
>> break the glass first.
>>
>> Regards
>>
>>
>> On 2/10/20 7:54 AM, l.flatz_at_bluewin.ch wrote:
>> > Hi,
>> >
>> > I would not set cs=forced in a DWH. These a logrunning queries and the
>> > plans should be as good as possible.
>> > Parse time will normally be a lesser concern.
>> > Just to give an example: Bind varaibles for a partition key should
>> > inhibit from partion stats being used on parsing.
>> >
>> > Regards
>> >
>> --
>> http://www.freelists.org/webpage/oracle-l
>>
>>
>>
>
> --
> Andrew W. Kerber
>
> 'If at first you dont succeed, dont take up skydiving.'
>
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Feb 10 2020 - 20:16:30 CET