Gregory Stark <[EMAIL PROTECTED]> writes: > Grzegorz JaÅkiewicz <[EMAIL PROTECTED]> writes: >> So my question would be, why isn't postgresql using indexes for OVERLAPS, >> and why optimizer doesn't substitute it with something like: >> >> (c <= a AND d > a) OR ( c >= a AND c < b)
> How would you use an index for that? I believe you can index overlaps-like tests using GIST on an interval-like data type --- look at contrib/seg for an example. The reason we don't automatically translate OVERLAPS is that the spec's definition of OVERLAPS is too weird for that to work; in particular it demands a true result for some cases in which one of the four endpoints is NULL, which'd be pretty hard to do with an interval-style index. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers