Markus Wanner <[EMAIL PROTECTED]> writes: > Hi, > > I'm having a hard time using an index scan. So far, I've done quite well with > ScanKeyInit for equality searches. But now I need to scan an index from a > given > starting point. Something like: > > (x, y, z,...) > (const, const, const,...) > > For the equality operatior, I've used get_sort_group_operators() in > combination > with get_opcode() to pass that on as the sk_func of the scan key. I slowly > begin to doubt if that's correct at all.
It's right for your equality case which is effectively x=const, y=const, z=const. It's not for row comparisons case for which you need a funny "header" ScanKey. See the comments in access/skey.h, search for "row comparisons". I'm not sure if there's a function to create this for you or if you have to do it yourself. Search for other places where SK_ROW_HEADER appears. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's On-Demand Production Tuning -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
