Обсуждение: select like...not using index

Sometime between yesterday and today queries in the form of
"select * from t where t.f like 'k%'" have been broken so that they
never use the index (on win32, not sure about others).

On win32, at least, they have been broken for a while but this was due
to a known issue based on the locales.  AFAICT, the current cvs has
addressed this issue and (show lc_collate returns C) there seems to be
no reason why the queries aren't working properly.

Merlin

> Sometime between yesterday and today queries in the form of
> "select * from t where t.f like 'k%'" have been broken so that they
> never use the index (on win32, not sure about others).
>
> On win32, at least, they have been broken for a while but this was due
> to a known issue based on the locales.  AFAICT, the current cvs has
> addressed this issue and (show lc_collate returns C) there seems to be
> no reason why the queries aren't working properly.
>
> Merlin

Did you do an ANALYZE on the table?
Are there a lot of duplicate keys?
How big is the table?
What does the "explain" look like?

"Merlin Moncure" <merlin.moncure@rcsonline.com> writes:
> Sometime between yesterday and today queries in the form of
> "select * from t where t.f like 'k%'" have been broken so that they
> never use the index (on win32, not sure about others).

Not here ... and I've seen no commits that I'd have thought would affect
that.  Check for local configuration changes.

            regards, tom lane