Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 7218F64FD0F for ; Tue, 22 Jul 2008 10:40:26 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 23868-03 for ; Tue, 22 Jul 2008 10:39:53 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from blu0-omc1-s32.blu0.hotmail.com (blu0-omc1-s32.blu0.hotmail.com [65.55.116.43]) by postgresql.org (Postfix) with ESMTP id 4DCB865016A for ; Tue, 22 Jul 2008 10:39:59 -0300 (ADT) Received: from BLU144-W43 ([65.55.116.9]) by blu0-omc1-s32.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 22 Jul 2008 06:39:58 -0700 Message-ID: Content-Type: multipart/alternative; boundary="_5981ec56-bdc7-4d82-909d-ed77cc0d0e32_" X-Originating-IP: [204.132.58.73] From: dx k9 To: posgres support Subject: shared_buffers and shmmax Date: Tue, 22 Jul 2008 09:39:57 -0400 Importance: Normal MIME-Version: 1.0 X-OriginalArrivalTime: 22 Jul 2008 13:39:58.0015 (UTC) FILETIME=[6E9F54F0:01C8EC00] X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.001 tagged_above=0 required=5 tests=HTML_MESSAGE=0.001 X-Spam-Level: X-Archive-Number: 200807/185 X-Sequence-Number: 29795 --_5981ec56-bdc7-4d82-909d-ed77cc0d0e32_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi=2C I'm trying to understand what the documentation means by bytes per incremen= t=2C what is the increment supposed to be bytes=2C MB=2C or Kb. I have my = shared_buffers set to 577 MB(4 instances) and I'm multiplying by 8400 bytes= . I would think I would want to keep everything in bytes and not mulitply = bytes times MB=2C but this is what table 17-2 implies. If I convert 577 to= bytes and multiply=2C my calculator goes exponential on me. I'm going thro= ugh this table and adding up to see what my shmmax should be (it's 7.5 GB) = out of a total memory of 16 GB with 1000 max_connections right now. What s= hould I use as the "increment" value in regards to shared buffers=2C 577=2C= 590848 or 605028352 ?=20 =20 a) 577 MB (This seems too small) b) 590=2C848 Kb (this seems just right) c) 605=2C028=2C352 bytes (this seems too big=2C I hope it's not c) =20 Thanks=2C ~DjK =20 Table 17-2. Configuration parameters affecting PostgreSQL's shared memory u= sage Name Approximate multiplier (bytes per increment) as of 8.3 max_connections 1800 + 270 * max_locks_per_transaction autovacuum_max_workers 1800 + 270 * max_locks_per_transaction max_prepared_transactions 770 + 270 * max_locks_per_transaction shared_buffers 8400 (assuming 8 kB BLCKSZ) wal_buffers 8200 (assuming 8 kB XLOG_BLCKSZ) max_fsm_relations 70 max_fsm_pages 6 Fixed space requirements 770 kB _________________________________________________________________ Stay in touch when you're away with Windows Live Messenger. http://www.windowslive.com/messenger/overview.html?ocid=3DTXT_TAGLM_WL_mess= enger2_072008= --_5981ec56-bdc7-4d82-909d-ed77cc0d0e32_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi=2C
I'm trying to understand what the documentation means by bytes per incremen= t=2C what is the increment supposed to be bytes=2C MB=2C or Kb. =3B I h= ave my shared_buffers set to 577 MB(4 instances) =3Band I'm multiplying= by 8400 bytes. =3B I would think I would want to keep everything in by= tes and not mulitply bytes times MB=2C but this is what table 17-2 implies.= =3B If I convert 577 to bytes and multiply=2C my calculator goes expon= ential on me. I'm going through this table and adding up to see what my shm= max should be (it's 7.5 GB) out of a total memory of 16 GB with 1000 max_co= nnections right now. =3B What should I use as the "increment" value in = regards to shared buffers=2C 577=2C 590848 or 605028352 =3B?
=3B
a) 577 MB (This seems too small)
b) 590=2C848 Kb (this seems just right)
c) 605=2C028=2C352 bytes =3B (this seems too big=2C I hope it's not c)<= BR> =3B
Thanks=2C
~DjK
=3B
Table 17-2. Configuration parameters affecting PostgreSQL's shared memory usage

Name	Approximate multiplier (bytes per increment) as of 8.3
max_connecti= ons	1800 + 270 * max_locks_per_transaction
autov= acuum_max_workers	1800 + 270 * max_locks_per_transaction
max_= prepared_transactions	770 + 270 * max_locks_per_transaction
shared_buffers<= /FONT>	8400 (assuming 8 kB `BLCKSZ`)
wal_buffers<= /A>	8200 (assuming 8 kB `XLOG_BLCKSZ`)
max_fsm_rela= tions	70
max_fsm_pages	6
Fixed space requirements	770 kB

Stay in touch when you'= re away with Windows Live Messenger. IM anytime you're online. = --_5981ec56-bdc7-4d82-909d-ed77cc0d0e32_--