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
