Re: very slow left join

On Fri, 16 May 2008, Scott Marlowe wrote:

> Well, I'm guessing that you aren't in locale=C and that the text

Correct, I am not. And my understanding is that by moving to the C locale,
I would loose utf8 validation, so I don't want to go there. Though, it's
news to me that I would get any kind of select performance boost with
locale=C. Why would it help?

> functions in your query aren't indexed.  Try creating an index on them
> something like:
>
> create index abc_txtfield_func on mytable (substring(textfield,1,5));
>
> etc and see if that helps.

It does not. :(