Hi Steve, Yes I see these messages in our log. Is there a solution to this? Thanks, Anne -----Original Message----- From: Steve Singer [mailto:st...@ssinger.info] Sent: Monday, April 22, 2013 1:26 PM To: Anne Rosset Cc: pgsql-hackers@postgresql.org Subject: Re: [HACKERS] Performance with the new security release?
On 13-04-22 04:15 PM, Anne Rosset wrote: > Hi Steve, > Thanks for your reply. > We are now running 9.0.13. Before it was 9.0.7. > How can I find out if we are running into this issue: "ie if > statistics are no longer being updated because analyze can't get the > exclusive lock for truncation"? This issue is discussed in the thread http://www.postgresql.org/message-id/CAMkU=1xYXOJp=jLAASPdSAqab-HwhA_tnRhy+JUe=4=b=v3...@mail.gmail.com If your seeing messages in your logs of the form: automatic vacuum of table XXX.YYY cannot (re)acquire exclusive lock for truncate scan" then you might be hitting this issue. > I will dig into our logs to see for the query times. > Thanks, > Anne > > -----Original Message----- > From: Steve Singer [mailto:st...@ssinger.info] > Sent: Monday, April 22, 2013 12:59 PM > To: Anne Rosset > Cc: pgsql-hackers@postgresql.org > Subject: Re: [HACKERS] Performance with the new security release? > > On 13-04-22 01:38 PM, Anne Rosset wrote: >> Hi, >> We are seeing some overall performance degradation in our application >> since we installed the security release. Other commits were also >> done at the same time in the application so we don't know yet if the >> degradation has any relationship with the security release. >> >> While we are digging into this, I would like to know if it is possible >> that the release has some impact on performance. After reading this >> "It was created as a side effect of a refactoring effort to make >> establishing new connections to a PostgreSQL server faster, and the >> associated code more maintainable.", I am thinking it is quite possible. >> >> Please let me know. Thanks, > Exactly which version of PostgreSQL are you running? (we released security > update releases for multiple PG versions). Also which version were you > running before? > > There were some changes to analyze/vacuum in the previous set of minor > releases that could cause performance issues in some cases (ie if statistics > are no longer being updated because analyze can't get the > exclusive lock for truncation). There might be other unintended > performance related changes. > > Are all queries taking longer or only some? Can you find any sort of pattern > that might help narrow the issue? > > Steve > >> Anne >> >> > > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
