[Michael Fuhr - Mon at 07:54:29AM -0600] > The message subject is "timestamp indexing" but you don't mention > whether you have an index on the timestamp column. Do you?
Yes. Sorry for not beeing explicit on that. > Could you post an example query and its EXPLAIN ANALYZE output? If > the query uses a sequential scan then it might also be useful to see > the EXPLAIN ANALYZE output with enable_seqscan turned off. Since > caching can cause a query to be significantly faster after being run > several times, it might be a good idea to run EXPLAIN ANALYZE three > times and post the output of the last run -- that should put the > queries under comparison on a somewhat equal footing (i.e., we don't > want to be misled about how much faster one query is than another > simply because one query happened to use more cached data on a > particular run). The actual statement was with 6 or 7 joins and very lengthy. I reduced it to a simple single join query which still did a sequential scan rather than an index scan (as expected), and I believe I already did a follow-up mail including "explain analyze". All "explain analyze" in my previous mail was run until the resulting execution time had stabilized, relatively. I will try with "set enable_seqscan off" when I get back to the office. > How many records are in the tables you're querying? Also answered on in my follow-up. > Are you regularly > vacuuming and analyzing the database or the individual tables? Vacuum is run nightly, and I also did a manual "vacuum analyze table" on the table in question. > Are > any of the tables clustered? If so, on what indexes and how often > are you re-clustering them? Huh? :) > What version of PostgreSQL are you using? Also answered in my follow-up - "not yet pg8" :) ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]