On 2012-02-09 21:09, Robert Haas wrote:
That doesn't make sense to me. If you probe index A for rows where a = 1 and find that CTID (100,1) is such a row, and now want to return a column value b that is not present in that index, the fastest way to get the row is going to be to fetch block 100 from the heap and return the data out of the first tuple. To get the value out of some other index that does include column b would require scanning the entire index looking for that CTID, just so you could then grab the corresponding index tuple, which wouldn't make any sense at all.
You're right, in my head, everything it wired up against my primary keys, of-course that isn't the case for the DB. Sorry for the noise. -- Jesper -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
