On Sun, 19 May 2002, Andriy I Pilipenko wrote:
> Please enter a FULL description of your problem: > ------------------------------------------------ > > I've upgraded from 7.0.3 to 7.2.1 and noticed that queries like > > SELECT ... WHERE field LIKE 'something%' > > take too much time to execute now. Are you sure that you're running in C locale? If you're unsure, you can build pg_controldata in contrib and check. (From comments in recent sources: /* * We want test whether the database's LC_COLLATE setting is safe for * LIKE/regexp index optimization. * * The key requirement here is that given a prefix string, say "foo", * we must be able to generate another string "fop" that is greater * than all strings "foobar" starting with "foo". Unfortunately, a * non-C locale may have arbitrary collation rules in which "fop" > * "foo" is not sufficient to ensure "fop" > "foobar". Until we can * come up with a more bulletproof way of generating the upper-bound * string, the optimization is disabled in all non-C locales. * * (In theory, locales other than C may be LIKE-safe so this function * could be different from lc_collate_is_c(), but in a different * theory, non-C locales are completely unpredicable so it's unlikely * to happen.) */ ) ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
