> > where productname is in the product table, and lotname in the lot
> > table. I would be interested in creating an index such as
>
> > CREATE INDEX ix_vw_lot ON vw_lot (lotname, productname);
>
> What purpose would this serve that indexes on the separate tables
> wouldn't serve?
>
> > The index would be enough to cover 90% of the queries against
> > lot the lot and inventory tables.
>
> This sounds to me like you are suffering from a common misconception.
> Postgres cannot answer queries from the contents of indexes alone.
Yes, thanks Tom. This is precisely what I was missing. I searched the
archives for the reason why this is so, but I found only one message
mentioning the MVCC mechanism. Can you point me in the right
direction? I would like to understand the issue.
IMHO, a change in this area could deliver great performance improvements.
-Tiago
