Re: PGA_AGGREGATE_TARGET, AUTO PGA TARGET and WORKAREA_SIZE_POLICY
Date: Mon, 9 Oct 2017 15:06:44 -0400
Message-ID: <94dea893-f120-c96e-c8c3-1f7ed048b94c_at_gmail.com>
Hi Ram,
SYS processes are exempt from almost any limitations. You should never,
ever log into database as SYS, especially if the database is 12c.
Previous releases could have not been backed up without logging in as
SYS, but 12c has a special role called "SYSBACKUP" which allows the
database to backed up without logging in as SYS. Logging in as SYS means
that you are doing database maintenance. Period. In such context, it
doesn't matter how much PGA is burned by the user SYS.
As for the untunable memory, the expression refers to the segments over
which the administrator has no control, like code, stack and bss.
Overall memory parameters are controlled by the OS. For Linux, the page
I usually recommend is the following:
PS:
On 10/09/2017 02:30 PM, Ram Raman wrote:
Untunable memory is also defined by an undocumented parameter
_ora_alzheimer_max_size.
> Thanks, I did not realize that SYS' processes are exempted from that
> limit. So, it is still possible for the usage to exceed PAL, even in 12c.
>
> Can someone explain what is "most untunable memory" ?
>
>
> On Fri, Oct 6, 2017 at 5:57 PM, Mladen Gogala <gogala.mladen_at_gmail.com
> <mailto:gogala.mladen_at_gmail.com>> wrote:
>
> Hi Ravi,
>
> I know that this is unexpected, but Oracle actually puts the
> documentation on the Internet for free. The first thing I would
> try is this:
>
> https://docs.oracle.com/database/121/REFRN/GUID-E364D0E5-19F2-4081-B55E-131DF09CFDB3.htm#REFRN10328
> <https://docs.oracle.com/database/121/REFRN/GUID-E364D0E5-19F2-4081-B55E-131DF09CFDB3.htm#REFRN10328>
>
> This document has a section with the title "What happens when
> PGA_AGGREGATE_LIMIT is exceeded". I will not ruin you the pleasure
> of reading the documentation by telling you the ending.
>
> Regards
>
>
> On 10/06/2017 06:05 PM, Ravi Teja Bellamkonda wrote:
>> It would be really helpful if someone can throw some light on
>> this. I understand that workarea_size_policy parameter set to
>> auto is related to this. But wanted to confirm that PGA used
>> actually crosses the PGA_AGGREGATE_LIMIT. Is there any
>> documentation which states that PGA_AGGREGATE_LIMIT is a soft limit.
>>
>> It would be very helpful, if someone can clarify.
>>
>> --
>> Thanks & Regards,
>> Ravi Teja
>
> --
> Mladen Gogala
> Oracle DBA
> Tel:(347) 321-1217 <tel:%28347%29%20321-1217>
>
>
>
>
> --
>
--
Mladen Gogala
Oracle DBA
Tel: (347) 321-1217
--
http://www.freelists.org/webpage/oracle-l
Received on Mon Oct 09 2017 - 21:06:44 CEST