On 10/4/06, Richard Huxton <dev@xxxxxxxxxxxx> wrote:
Issue "set enable_seqscan=false" and then run your explain analyse. If your query uses the index, what is the estimated cost? If the estimated cost is larger than a seq-scan that would indicate your configuration settings are badly out-of-range.
I did that and it still used seq-scan.
If the index isn't used, then we have problem #3. I think this is what you are actually seeing. Your locale is something other than "C" and PG doesn't know how to use like with indexes. Read up on operator classes or change your locale. http://www.postgresql.org/docs/8.1/static/indexes-opclass.html
Aha - that sounds like it - this is the output from locale LANG=en_US.UTF-8 LC_CTYPE="en_US.UTF-8" LC_NUMERIC="en_US.UTF-8" LC_TIME="en_US.UTF-8" LC_COLLATE="en_US.UTF-8" LC_MONETARY="en_US.UTF-8" LC_MESSAGES="en_US.UTF-8" LC_PAPER="en_US.UTF-8" LC_NAME="en_US.UTF-8" LC_ADDRESS="en_US.UTF-8" LC_TELEPHONE="en_US.UTF-8" LC_MEASUREMENT="en_US.UTF-8" LC_IDENTIFICATION="en_US.UTF-8" LC_ALL= I guess it cannot determine the collating sequence? I'm not too familiar with unix locale issues - does this output match your problem description? Can you explain how to change my locale to 'C'? (I'm quite happy for you to tell me to RTFM, as I know this is not a linux user mailing list :) -- Simon Godden
