Re: sizing sort_area_size
This is the true way only until more advanced mechanisms for digging into a problem become available. (They might already be here, without our knowing ;) Tanel. - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Friday, September 19, 2003 8:29 PM > I'll amend The True Way (TM) based on your suggestions. > > -- > Mladen Gogala > Oracle DBA > > > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of Tanel Poder > > Sent: Friday, September 19, 2003 1:10 PM > > To: Multiple recipients of list ORACLE-L > > Subject: Re: sizing sort_area_size > > > > > > > That gives you only the current use of sort segments. The > > same applies > > > to reasoning based on v$sort_usage and V$TEMP_SPACE_HEADER. > > The only > > > True Way(TM) of tuning sorts is by using v$sysstat and v$sesstat > > > values, > > > > I think tuning sorts based on "in-memory sort" vs "not-in > > memory sort" calculations might be ok in simple OLTP > > envivronments, but in modern DW and OLAP world they give too > > simplistic overiew of what's happening in database. I'd > > definitely add events 10032 and 10033 trace for tuning big > > sorts (v$tempstat and even 10046 trace with waits can be > > somewhat useful as well). > > > > Tanel. > > > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > -- > > Author: Tanel Poder > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > > San Diego, California-- Mailing list and web hosting services > > - > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') > > and in the message BODY, include a line containing: UNSUB > > ORACLE-L (or the name of mailing list you want to be removed > > from). You may also send the HELP command for other > > information (like subscribing). > > > > > > > Note: > This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Wang Trading LLC and any of its subsidiaries each reserve the right to monitor all e-mail communications through its networks. > Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorized to state them to be the views of any such entity. > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Mladen Gogala > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: sizing sort_area_size
I'll amend The True Way (TM) based on your suggestions. -- Mladen Gogala Oracle DBA > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Tanel Poder > Sent: Friday, September 19, 2003 1:10 PM > To: Multiple recipients of list ORACLE-L > Subject: Re: sizing sort_area_size > > > > That gives you only the current use of sort segments. The > same applies > > to reasoning based on v$sort_usage and V$TEMP_SPACE_HEADER. > The only > > True Way(TM) of tuning sorts is by using v$sysstat and v$sesstat > > values, > > I think tuning sorts based on "in-memory sort" vs "not-in > memory sort" calculations might be ok in simple OLTP > envivronments, but in modern DW and OLAP world they give too > simplistic overiew of what's happening in database. I'd > definitely add events 10032 and 10033 trace for tuning big > sorts (v$tempstat and even 10046 trace with waits can be > somewhat useful as well). > > Tanel. > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Tanel Poder > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') > and in the message BODY, include a line containing: UNSUB > ORACLE-L (or the name of mailing list you want to be removed > from). You may also send the HELP command for other > information (like subscribing). > Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Wang Trading LLC and any of its subsidiaries each reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorized to state them to be the views of any such entity. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Mladen Gogala INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: sizing sort_area_size
Tanel, you are a genuine treasure and a very nice addition to this list.
--
Mladen Gogala
Oracle DBA
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Tanel Poder
> Sent: Friday, September 19, 2003 12:55 PM
> To: Multiple recipients of list ORACLE-L
> Subject: Re: sizing sort_area_size
>
>
> Hi!
>
> Just few additions about 9i's nice features for tuning sorts,
> hash joins & other work area operations:
>
> SQL> select n.name,s.value
> 2 from v$statname n,v$sesstat s
> 3 where n.statistic#=s.statistic#
> 4 and n.name like '%workarea executions%'
> 5 and s.sid in (
> 6 select sid from v$session
> 7 where audsid=sys_context('USERENV','SESSIONID')
> 8 );
>
> NAME
> VALUE
> --
> -- --
> workarea executions - optimal
> 136
> workarea executions - multipass
> 0
> workarea executions - onepass
> 1
>
> Optimal means in-memory work area operations (sorts, hash
> joins, bitmap merges, etc.), onepass & multipass mean on disk
> operations. In OLAP and reporting environments, on-disk
> sorting or hasing is often unavoidable, but you should try to
> keep your sorts away from multipass executions, this will
> heavily hit your TEMP TS IO (sort runs can't be merged in
> sort area in one run, several runs needed) also CPU (some
> data comparisions have to be done semi-redundantly). The
> larger your sort_area_size, the smaller is the chance you'll
> need multipass sorting. (v$sql_workarea_histograms table can
> be useful for finding optimal tradeoff between PGA memory
> usage and temp ts IO on system level. On session level,
> v$sql_ workarea and v$sql_workare_active contain very
> interesting statistics).
>
> Tanel.
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, September 19, 2003 5:24 PM
>
>
> > The following query will give you an idea how to tune sort
> area size:
> > 1 select n.name,s.value
> > 2 from v$statname n,v$sesstat s
> > 3 where n.statistic#=s.statistic#
> > 4and n.name like '%sort%'
> > 5and s.sid in (select sid from v$session
> > 6* where
> audsid=sys_context('USERENV','SESSIONID'))
> > SQL> /
> >
> > NAME
> VALUE
> >
> > -
> -
> > sorts (memory)
> 26
> > sorts (disk)
> 0
> > sorts (rows)
> 87
> >
> > SQL>
> >
> > --
> > Mladen Gogala
> > Oracle DBA
> >
> >
> >
> > > -Original Message-
> > > From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf
> > > Of [EMAIL PROTECTED]
> > > Sent: Thursday, September 18, 2003 3:10 PM
> > > To: Multiple recipients of list ORACLE-L
> > > Subject: sizing sort_area_size
> > >
> > >
> > > I have been doing some alter sessions to improve performance of
> > > gigabyte sized 'minus' operations. How do I tell if this
> is helping
> > > other than completion time?
> > >
> > > I believe that if LIOs to PIOs ratio improves with the SAME query
> > > then sort_area_size has helped right?(notice Im not trying to
> > > improve my cache/hit ratio).
> > >
> > > I get this from v$sess_io.
> > >
> > > how do I tell how much temp tablespace my session uses? I
> cant find
> > > a statistic for it? I see that I used up all my PGA since
> PGA size
> > > and PGA max size are equal in v$sesstat.
> > >
> > > anything else I can look at?
> > >
> > > --
> > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > --
> > > Author: <[EMAIL PROTECTED]
> > > INET: [EMAIL PROTECTED]
> > >
> > > Fat City Network Services-- 858-538-5051
> http://www.fatcity.com
> > > San Diego, California-- Mailing list and web
> hosting services
> > >
>
> > > -
> > > To REMOVE yourself from this mailing list, send an E-Mail message
> > > to: [EMAIL PROTECTED] (not
Re: sizing sort_area_size
> That gives you only the current use of sort segments. The same applies > to reasoning based on v$sort_usage and V$TEMP_SPACE_HEADER. The only > True Way(TM) of tuning sorts is by using v$sysstat and v$sesstat values, I think tuning sorts based on "in-memory sort" vs "not-in memory sort" calculations might be ok in simple OLTP envivronments, but in modern DW and OLAP world they give too simplistic overiew of what's happening in database. I'd definitely add events 10032 and 10033 trace for tuning big sorts (v$tempstat and even 10046 trace with waits can be somewhat useful as well). Tanel. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: sizing sort_area_size
Hi!
Just few additions about 9i's nice features for tuning sorts, hash joins &
other work area operations:
SQL> select n.name,s.value
2 from v$statname n,v$sesstat s
3 where n.statistic#=s.statistic#
4 and n.name like '%workarea executions%'
5 and s.sid in (
6 select sid from v$session
7 where audsid=sys_context('USERENV','SESSIONID')
8 );
NAME VALUE
--
workarea executions - optimal 136
workarea executions - multipass 0
workarea executions - onepass 1
Optimal means in-memory work area operations (sorts, hash joins, bitmap
merges, etc.), onepass & multipass mean on disk operations. In OLAP and
reporting environments, on-disk sorting or hasing is often unavoidable, but
you should try to keep your sorts away from multipass executions, this will
heavily hit your TEMP TS IO (sort runs can't be merged in sort area in one
run, several runs needed) also CPU (some data comparisions have to be done
semi-redundantly). The larger your sort_area_size, the smaller is the chance
you'll need multipass sorting. (v$sql_workarea_histograms table can be
useful for finding optimal tradeoff between PGA memory usage and temp ts IO
on system level. On session level, v$sql_ workarea and v$sql_workare_active
contain very interesting statistics).
Tanel.
- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, September 19, 2003 5:24 PM
> The following query will give you an idea how to tune sort area size:
> 1 select n.name,s.value
> 2 from v$statname n,v$sesstat s
> 3 where n.statistic#=s.statistic#
> 4and n.name like '%sort%'
> 5and s.sid in (select sid from v$session
> 6* where audsid=sys_context('USERENV','SESSIONID'))
> SQL> /
>
> NAME
VALUE
> -
-
> sorts (memory)
26
> sorts (disk)
0
> sorts (rows)
87
>
> SQL>
>
> --
> Mladen Gogala
> Oracle DBA
>
>
>
> > -Original Message-
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> > Behalf Of [EMAIL PROTECTED]
> > Sent: Thursday, September 18, 2003 3:10 PM
> > To: Multiple recipients of list ORACLE-L
> > Subject: sizing sort_area_size
> >
> >
> > I have been doing some alter sessions to improve performance
> > of gigabyte sized 'minus' operations. How do I tell if this
> > is helping other than completion time?
> >
> > I believe that if LIOs to PIOs ratio improves with the SAME
> > query then sort_area_size has helped right?(notice Im not
> > trying to improve my cache/hit ratio).
> >
> > I get this from v$sess_io.
> >
> > how do I tell how much temp tablespace my session uses? I
> > cant find a statistic for it? I see that I used up all my PGA
> > since PGA size and PGA max size are equal in v$sesstat.
> >
> > anything else I can look at?
> >
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: <[EMAIL PROTECTED]
> > INET: [EMAIL PROTECTED]
> >
> > Fat City Network Services-- 858-538-5051 http://www.fatcity.com
> > San Diego, California-- Mailing list and web hosting services
> > -
> > To REMOVE yourself from this mailing list, send an E-Mail message
> > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru')
> > and in the message BODY, include a line containing: UNSUB
> > ORACLE-L (or the name of mailing list you want to be removed
> > from). You may also send the HELP command for other
> > information (like subscribing).
> >
>
>
>
>
> Note:
> This message is for the named person's use only. It may contain
confidential, proprietary or legally privileged information. No
confidentiality or privilege is waived or lost by any mistransmission. If
you receive this message in error, please immediately delete it and all
copies of it from your system, destroy any hard copies of it and notify the
sender. You must not, directly or indirectly, use, disclose, distribute,
print, or copy any part of this message if you are not the intended
recipient. Wang Trading LLC and any of its subsidiaries each reserve the
right to monitor all e-mail communications through its networks.
> Any views expressed in this message are those of the individual sender,
except where the message states otherwise and the sender is authorized to
state them to be the views of any such entity.
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: Mladen Gogala
> INET: [EMAIL PROTECTED]
>
> Fat City Network Services-- 858-538-5051 http://www.fatcity.com
> San Diego, California-- Mailing list and web hosting services
> -
RE: sizing sort_area_size
That gives you only the current use of sort segments. The same applies to reasoning based on v$sort_usage and V$TEMP_SPACE_HEADER. The only True Way(TM) of tuning sorts is by using v$sysstat and v$sesstat values, That gives you an overview of the sort statistics since the instance (or the session) was started. If you need a lot of memory quickly, you just set SORT_AREA_SIZE to some reasonable value for a short period of time, then lower it again and hope for the best. -- Mladen Gogala Oracle DBA > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Hitchman, Peter > Sent: Friday, September 19, 2003 11:05 AM > To: Multiple recipients of list ORACLE-L > Subject: RE: sizing sort_area_size > > > Hi, > Looking at v$sort_segment also can gve you a good idea of how > much space you are using in your temporary tablespace, across > the current uptime of the instance, assuming that it is a > true temporary tablespace. > > Regards > > Pete > > -Original Message- > Sent: 18 September 2003 23:35 > To: Multiple recipients of list ORACLE-L > > > > I have been doing some alter sessions to improve performance of > > gigabyte > sized 'minus' operations. How do I tell if this is helping > other than completion time? > > > > I believe that if LIOs to PIOs ratio improves with the SAME > query then > sort_area_size has helped right?(notice Im not trying to > improve my cache/hit ratio). > > If you see less direct IO waits on your temporary tablespace, > then increasing s_a_s has helped. > > > > > I get this from v$sess_io. > > > > how do I tell how much temp tablespace my session uses? I > cant find a > statistic for it? I see that I used up all my PGA since PGA > size and PGA max size are equal in v$sesstat. > > select * from v$sort_usage where sid = ; > > > anything else I can look at? > > Activity on temp tablespace from v$tempstat.. but it's only > good enough for comparing with baselines.. > > Tanel. > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Tanel Poder > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') > and in the message BODY, include a line containing: UNSUB > ORACLE-L (or the name of mailing list you want to be removed > from). You may also send the HELP command for other > information (like subscribing). > > __ > > The information contained in this email is confidential and > intended only for the use of the individual or entity named > above. If the reader of this message is not the intended > recipient, you are hereby notified that any dissemination, > distribution, or copying of this communication is strictly > prohibited. Thomson Scientific will accept no responsibility > or liability in respect to this email other than to the addressee. > If you have received this communication in error, please > notify us immediately via email: [EMAIL PROTECTED] > __ > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Hitchman, Peter > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') > and in the message BODY, include a line containing: UNSUB > ORACLE-L (or the name of mailing list you want to be removed > from). You may also send the HELP command for other > information (like subscribing). > Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Wang Trading LLC and any o
RE: sizing sort_area_size
Hi, Looking at v$sort_segment also can gve you a good idea of how much space you are using in your temporary tablespace, across the current uptime of the instance, assuming that it is a true temporary tablespace. Regards Pete -Original Message- Sent: 18 September 2003 23:35 To: Multiple recipients of list ORACLE-L > I have been doing some alter sessions to improve performance of gigabyte sized 'minus' operations. How do I tell if this is helping other than completion time? > > I believe that if LIOs to PIOs ratio improves with the SAME query then sort_area_size has helped right?(notice Im not trying to improve my cache/hit ratio). If you see less direct IO waits on your temporary tablespace, then increasing s_a_s has helped. > > I get this from v$sess_io. > > how do I tell how much temp tablespace my session uses? I cant find a statistic for it? I see that I used up all my PGA since PGA size and PGA max size are equal in v$sesstat. select * from v$sort_usage where sid = ; > anything else I can look at? Activity on temp tablespace from v$tempstat.. but it's only good enough for comparing with baselines.. Tanel. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). __ The information contained in this email is confidential and intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. Thomson Scientific will accept no responsibility or liability in respect to this email other than to the addressee. If you have received this communication in error, please notify us immediately via email: [EMAIL PROTECTED] __ -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hitchman, Peter INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: sizing sort_area_size
The following query will give you an idea how to tune sort area size:
1 select n.name,s.value
2 from v$statname n,v$sesstat s
3 where n.statistic#=s.statistic#
4and n.name like '%sort%'
5and s.sid in (select sid from v$session
6* where audsid=sys_context('USERENV','SESSIONID'))
SQL> /
NAME VALUE
--
sorts (memory) 26
sorts (disk) 0
sorts (rows) 87
SQL>
--
Mladen Gogala
Oracle DBA
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of [EMAIL PROTECTED]
> Sent: Thursday, September 18, 2003 3:10 PM
> To: Multiple recipients of list ORACLE-L
> Subject: sizing sort_area_size
>
>
> I have been doing some alter sessions to improve performance
> of gigabyte sized 'minus' operations. How do I tell if this
> is helping other than completion time?
>
> I believe that if LIOs to PIOs ratio improves with the SAME
> query then sort_area_size has helped right?(notice Im not
> trying to improve my cache/hit ratio).
>
> I get this from v$sess_io.
>
> how do I tell how much temp tablespace my session uses? I
> cant find a statistic for it? I see that I used up all my PGA
> since PGA size and PGA max size are equal in v$sesstat.
>
> anything else I can look at?
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: <[EMAIL PROTECTED]
> INET: [EMAIL PROTECTED]
>
> Fat City Network Services-- 858-538-5051 http://www.fatcity.com
> San Diego, California-- Mailing list and web hosting services
> -
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru')
> and in the message BODY, include a line containing: UNSUB
> ORACLE-L (or the name of mailing list you want to be removed
> from). You may also send the HELP command for other
> information (like subscribing).
>
Note:
This message is for the named person's use only. It may contain confidential,
proprietary or legally privileged information. No confidentiality or privilege is
waived or lost by any mistransmission. If you receive this message in error, please
immediately delete it and all copies of it from your system, destroy any hard copies
of it and notify the sender. You must not, directly or indirectly, use, disclose,
distribute, print, or copy any part of this message if you are not the intended
recipient. Wang Trading LLC and any of its subsidiaries each reserve the right to
monitor all e-mail communications through its networks.
Any views expressed in this message are those of the individual sender, except where
the message states otherwise and the sender is authorized to state them to be the
views of any such entity.
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Mladen Gogala
INET: [EMAIL PROTECTED]
Fat City Network Services-- 858-538-5051 http://www.fatcity.com
San Diego, California-- Mailing list and web hosting services
-
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from). You may
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Re: sizing sort_area_size
can anyone recommend a good article managing sort_Area_size and understanding temp tablespace waits? - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Thursday, September 18, 2003 6:34 PM > > I have been doing some alter sessions to improve performance of gigabyte > sized 'minus' operations. How do I tell if this is helping other than > completion time? > > > > I believe that if LIOs to PIOs ratio improves with the SAME query then > sort_area_size has helped right?(notice Im not trying to improve my > cache/hit ratio). > > If you see less direct IO waits on your temporary tablespace, then > increasing s_a_s has helped. > > > > > I get this from v$sess_io. > > > > how do I tell how much temp tablespace my session uses? I cant find a > statistic for it? I see that I used up all my PGA since PGA size and PGA max > size are equal in v$sesstat. > > select * from v$sort_usage where sid = ; > > > anything else I can look at? > > Activity on temp tablespace from v$tempstat.. but it's only good enough for > comparing with baselines.. > > Tanel. > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Tanel Poder > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Ryan INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: sizing sort_area_size
> I have been doing some alter sessions to improve performance of gigabyte sized 'minus' operations. How do I tell if this is helping other than completion time? > > I believe that if LIOs to PIOs ratio improves with the SAME query then sort_area_size has helped right?(notice Im not trying to improve my cache/hit ratio). If you see less direct IO waits on your temporary tablespace, then increasing s_a_s has helped. > > I get this from v$sess_io. > > how do I tell how much temp tablespace my session uses? I cant find a statistic for it? I see that I used up all my PGA since PGA size and PGA max size are equal in v$sesstat. select * from v$sort_usage where sid = ; > anything else I can look at? Activity on temp tablespace from v$tempstat.. but it's only good enough for comparing with baselines.. Tanel. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
