On 4/3/07, Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
"Alex Deucher" <alexdeucher@xxxxxxxxx> writes:
> and here are the query plans referenced in my last email (apologies if
> you get these twice, they didn't seem to go through the first time,
> perhaps due to size?). I cut out the longer ones.
The first case looks a whole lot like 8.2 does not think it can use an
index for LIKE, which suggests strongly that you've used the wrong
locale in the 8.2 installation (ie, not C).
The second pair of plans may look a lot different but in principle they
ought to perform pretty similarly. I think the performance differential
may at root be that string comparison is way more expensive in the 8.2
installation, which again is possible if you went from C locale to some
other locale.
In short: check out "show lc_collate" in both installations.
OK, cool, the old one was C and the new one as not. So I dumped the
DB and re-inited the DB with the locale set to C, then reloaded the
dump, but I'm still getting the same behavior. Any ideas?
Thanks,
Alex
regards, tom lane
