Обсуждение: Vacuuming - how often?
I'm using 7.1 on redhat 7.1... I had a query result which startled me a bit... it was a simple join and the result was like a cartesian product like I hadn't bothered with a when clause. I ran vacuum from inside pgaccess and the results of the query changed to what I was expecting in the first place... What I'm wondering is what is the likely problem here? Does this mean that *regular* maintenance is required? the data in this database is pretty much append only.. with some updating, but next to zero deleting is done... any comments on this? thanks Scott.
Hello, An active database, should be vacummed nightly. It will keep things in tip top shape and help maintain the database overall. J On Tue, 13 Nov 2001, Scott Muir wrote: > I'm using 7.1 on redhat 7.1... > > I had a query result which startled me a bit... it was a simple join and > the result was like a cartesian product like I hadn't bothered with a when > clause. > > I ran vacuum from inside pgaccess and the results of the query changed to > what I was expecting in the first place... > > What I'm wondering is what is the likely problem here? Does this mean that > *regular* maintenance is required? the data in this database is pretty much > append only.. with some updating, but next to zero deleting is done... > > any comments on this? > > thanks > Scott. > > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org > -- -- by way of pgsql-general@commandprompt.com http://www.postgresql.info/ http://www.commandprompt.com/
At 06:32 PM 11/13/01 -0700, Scott Muir wrote: >I'm using 7.1 on redhat 7.1... > >I had a query result which startled me a bit... it was a simple join and >the result was like a cartesian product like I hadn't bothered with a when >clause. > >I ran vacuum from inside pgaccess and the results of the query changed to >what I was expecting in the first place... AFAIK in most typical cases results should not change because of a vacuum - performance may change, but the results shouldn't. If the results change then something is wrong - corrupted/buggy index perhaps. Cheerio, Link.