Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1Tj0me-0006dD-Vx for pgsql-performance@arkaria.postgresql.org; Thu, 13 Dec 2012 04:52:33 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1Tj0md-0008UE-Tw for pgsql-performance@arkaria.postgresql.org; Thu, 13 Dec 2012 04:52:31 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1Tj0md-0008U9-46 for pgsql-performance@postgresql.org; Thu, 13 Dec 2012 04:52:31 +0000 Received: from szxga02-in.huawei.com ([119.145.14.65]) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1Tj0mY-0005AX-F2 for pgsql-performance@postgresql.org; Thu, 13 Dec 2012 04:52:30 +0000 Received: from 172.24.2.119 (EHLO szxeml208-edg.china.huawei.com) ([172.24.2.119]) by szxrg02-dlp.huawei.com (MOS 4.3.4-GA FastPath queued) with ESMTP id AUC84188; Thu, 13 Dec 2012 12:52:18 +0800 (CST) Received: from SZXEML461-HUB.china.huawei.com (10.82.67.204) by szxeml208-edg.china.huawei.com (172.24.2.57) with Microsoft SMTP Server (TLS) id 14.1.323.3; Thu, 13 Dec 2012 12:52:16 +0800 Received: from blrprnc07ns (10.18.96.96) by szxeml461-hub.china.huawei.com (10.82.67.204) with Microsoft SMTP Server id 14.1.323.3; Thu, 13 Dec 2012 12:52:16 +0800 From: Hari Babu To: Subject: Memory issue for inheritance tables. Date: Thu, 13 Dec 2012 10:22:12 +0530 Message-ID: <004501cdd8ed$9e194f40$da4bedc0$@kommi@huawei.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0046_01CDD91B.B7D18B40" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Ac3Y7R2nkPCTqB7wSlGxi1ApRngr0AAADHwQ Content-Language: en-us X-Originating-IP: [10.18.96.96] X-CFilter-Loop: Reflected X-Pg-Spam-Score: 0.5 (/) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org ------=_NextPart_000_0046_01CDD91B.B7D18B40 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit One parent table, having 100 child tables. In this scenario we observed that delete and update are taking more memory for preparing a plan If the system under peak i am getting out of memory issue. i.e Select on parent table is using memory - 331456 in message context Delete on parent table is using memory - 3746432 in message context Delete on single child table is using memory - 8800 in message context Select on single child table is using memory - 9328 in message context For 250 child tables Select on parent table is using memory - 810864 in message context Delete on parent table is using memory - 21273088 in message context I had seen the plans for both delete & select on parent table almost same. why this much of memory increase in message context for delete and update operation. Regards, Hari babu. ------=_NextPart_000_0046_01CDD91B.B7D18B40 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

One parent = table, having 100 child tables.
In this = scenario we observed that delete and update are taking more memory for = preparing a plan

If the = system under peak i am getting out of memory issue.

i.e =
Select on = parent table is using memory - 331456 in message context =
Delete on = parent table is using memory - 3746432 in message context =

Delete on = single child table is using memory - 8800 in message context =
Select on = single child table is using memory - 9328 in message context =

For 250 = child tables
= Select on = parent table is using memory - = 810864 in = message context
= Delete on parent table is using memory - 21273088 = in message context

I had seen = the plans for both delete & select on parent table almost = same.
why this = much of memory increase in message context for delete and update = operation.

Regards,
Hari = babu.

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