Re: Have I b0rked something? Slow comparisons on "where x in (...)"

On Wed, May 02, 2007 at 05:59:49PM -0400, Tom Lane wrote:
> Stephen Harris <lists@spuddy.org> writes:

> >   "select stuff from table where index_key in (" .
> >       join(",",keys %hash) . ") AND non_index_row in ('xyz','abc','def')

> In what, a seq scan?

Yeah, if the number of comparisons exceeds 156 then it switched from
index scan to sequential scan.

> time, I can see where the time might get eaten up.  Where is the
> index_key column in the tuples, exactly?

First column.

--

rgds
Stephen