Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1ZisGV-0001iB-He for pgsql-hackers@arkaria.postgresql.org; Sun, 04 Oct 2015 23:00:23 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84) (envelope-from ) id 1ZisGT-0005io-Va for pgsql-hackers@arkaria.postgresql.org; Sun, 04 Oct 2015 23:00:22 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84) (envelope-from ) id 1ZisFA-0004D0-OC for pgsql-hackers@postgresql.org; Sun, 04 Oct 2015 22:59:00 +0000 Received: from relay3-d.mail.gandi.net ([2001:4b98:c:538::195]) by magus.postgresql.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.84) (envelope-from ) id 1ZisF4-0000OW-IZ for pgsql-hackers@postgresql.org; Sun, 04 Oct 2015 22:59:00 +0000 Received: from mfilter22-d.gandi.net (mfilter22-d.gandi.net [217.70.178.150]) by relay3-d.mail.gandi.net (Postfix) with ESMTP id 86D95A80AD; Mon, 5 Oct 2015 00:58:52 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mfilter22-d.gandi.net Received: from relay3-d.mail.gandi.net ([IPv6:::ffff:217.70.183.195]) by mfilter22-d.gandi.net (mfilter22-d.gandi.net [::ffff:10.0.15.180]) (amavisd-new, port 10024) with ESMTP id 6GgS0tmfI8iH; Mon, 5 Oct 2015 00:58:51 +0200 (CEST) X-Originating-IP: 98.122.164.227 Received: from [192.168.10.146] (unknown [98.122.164.227]) (Authenticated sender: adsend@dunslane.net) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 9A95DA80AB; Mon, 5 Oct 2015 00:58:47 +0200 (CEST) Subject: Re: Less than ideal error reporting in pg_stat_statements To: Tom Lane , Peter Geoghegan References: <5601D354.5000703@BlueTreble.com> <5913.1443822154@sss.pgh.pa.us> <9935.1443828452@sss.pgh.pa.us> <32385.1443976035@sss.pgh.pa.us> <26165.1443988873@sss.pgh.pa.us> <30415.1443996994@sss.pgh.pa.us> Cc: Jim Nasby , Pg Hackers From: Andrew Dunstan Message-ID: <5611AF21.9090900@dunslane.net> Date: Sun, 4 Oct 2015 18:58:41 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <30415.1443996994@sss.pgh.pa.us> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -2.6 (--) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org On 10/04/2015 06:16 PM, Tom Lane wrote: > Peter Geoghegan writes: >> To be clear: I wasn't sure why you though I falsely count entries with >> dropped texts within entry_dealloc(). > In the existing^H^H^Hprevious code, dropped-text entries would essentially > act as length-zero summands in the average calculation, whereas I think > we agree that they ought to be ignored; otherwise they decrease the > computed mean and thereby increase the probability of (useless) GC cycles. > In the worst case where the hashtable is mostly dropped-text entries, > which would for instance be the prevailing situation shortly after a GC > failure, we'd be calculating ridiculously small mean values and that'd > prompt extra GC cycles no? > > Sorry, I'm a bit late to this party. Does what you have committed mean people are less likely to see "Out of Memory" coming from pg_stat_statements? If not, what can be done about them short of a restart? And what bad effects follow from an event generating them? The docs seem to be quite silent on these points. cheers andrew -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers