Richard Huxton <dev@archonet.com> writes:
> Csaba Nagy wrote:
>> Based on the 3rd query of the OP, where the direct comparison results in
>> "true" for all the rows which matched the "like", I would exclude the
>> localisation issues variant... unless = is not equals in all cases ;-)
> Well spotted Csaba - that _would_ seem to point to the index.
No, localization issues should be real high on your list. In particular
I wonder whether this is the old bugaboo of using a database encoding
that's incompatible with the postmaster's locale setting. We've seen
that on some platforms strcoll() gets completely confused by this and
returns comparison results that are not even self-consistent.
Non-self-consistent comparison results can lead to an index that is
either actually or effectively corrupt (because index searches proceed
down the wrong tree path and thus fail to find items that should be
found). So the observation that only index searches fail is consistent
with this idea.
regards, tom lane
