Howard Rogers <hjr@xxxxxxxxxx> writes: > OK, Tom: I did actually account for the number of rows difference > before I posted, though I accept I didn't show you that. So here goes: > ... > Both queries return zero rows. One takes an awful lot longer than the > other. The only difference between them is that one searches for > 'ftx1' and the other searches for 'ftx0'. Well, this still doesn't tell us anything about what I think the critical point is, namely how many actual matches there are for ftx1 versus ftx0. Could we see counts for *just* those words without the other conditions? > So, I would still like to know if this performance difference when > encountering alpha-numeric "words" is dictionary-related, AFAIK there is no significant difference between treatment of pure alpha and mixed alphanumeric "words", at least not once you get past to_tsquery. I'm still expecting this is just a matter of how many index entries match. It's barely possible that you've got a dictionary configuration that makes the to_tsquery() function itself a lot slower in the alphanumeric case, but that should affect ftx1 and ftx0 equally. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
