Re: [PERFORM] Very specialised query

2009-03-27 Thread Matthew Wakeling
On Thu, 26 Mar 2009, I wrote: release-16.0-preview-14-mar=# \d location Table public.location Column | Type | Modifiers -+-+--- end | integer | start | integer | objectid| integer | id | integer | not

Re: [PERFORM] Very specialised query

2009-03-27 Thread Tom Lane
Matthew Wakeling matt...@flymine.org writes: Is there an operator class for integer for gist indexes that I can use? See contrib/btree_gist. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your

Re: [PERFORM] Very specialised query

2009-03-27 Thread Віталій Тимчишин
Hello. You could try addingAND l2.start l1.start to the first query. This will drop symmetric half of intersections (the ones that will remain are l2 inside or to the left of l1), but you can redo results by id1,id2 union all id2, id1 and may allow to use start index for between, for my

Re: [PERFORM] I have a fusion IO drive available for testing

2009-03-27 Thread Jeff
On Mar 26, 2009, at 8:47 AM, Dave Cramer wrote: So far using dd I am seeing around 264MB/s on ext3, 335MB/s on ext2 write speed. So the question becomes what is the best filesystem for this drive? Anyone want me to run anything on it ? Dave I'd be more interested in the random io

Re: [PERFORM] I have a fusion IO drive available for testing

2009-03-27 Thread david
On Thu, 26 Mar 2009, Dave Cramer wrote: So far using dd I am seeing around 264MB/s on ext3, 335MB/s on ext2 write speed. So the question becomes what is the best filesystem for this drive? until the current mess with ext3 and fsync gets resolved, i would say it would probably be a bad

Re: [PERFORM] Very specialised query

2009-03-27 Thread Matthew Wakeling
On Fri, 27 Mar 2009, Віталій Тимчишин wrote: ...an index on (objectid, start) would help... Definitely. You could try  adding    AND l2.start l1.start to the first query.  This will drop symmetric half of intersections (the ones that will remain are l2 inside or to the left of l1), but you

Re: [PERFORM] I have a fusion IO drive available for testing

2009-03-27 Thread Jeff
On Mar 27, 2009, at 1:30 PM, da...@lang.hm wrote: for the WAL you definantly don't need the journal, for the data I'm not sure. I believe that postgres does appropriate fsync calls so is safe on a non-journaling filesystem. the fusionIO devices are small enough that a fsync on them does

Re: [PERFORM] Very specialised query

2009-03-27 Thread Tom Lane
Matthew Wakeling matt...@flymine.org writes: Notice the two different index conditions: (l1.end l2.start) AND (l1.start l2.start) - between (l1.end l2.start) AND (l1.start = l2.start) - open-ended Both have a cost of (cost=0.00..123.10 rows=4809 width=12) Postgres estimates

Re: [PERFORM] I have a fusion IO drive available for testing

2009-03-27 Thread David Rees
On Fri, Mar 27, 2009 at 10:30 AM, da...@lang.hm wrote: On Thu, 26 Mar 2009, Dave Cramer wrote: So far using dd I am seeing around 264MB/s on ext3, 335MB/s on ext2 write speed. So the question becomes what is the best filesystem for this drive? until the current mess with ext3 and fsync gets

Re: [PERFORM] Very specialised query

2009-03-27 Thread Marc Mamin
Hello, if your data are mostly static and you have a few mains objects, maybe you can have some gain while defining conditional indexes for those plus one for the rest and then slicing the query: create index o_1x on X (start,end,id) where object_id = 1 create index o_2x on X (start,end,id)