Re: VIEWS compared to Nodes as Windows into data

A copnstraint or a coincidence. But I would tend to forgive an optimizer that didn't keep track of the coincidences, since keeping track of them would imlpy a fairly large cost for fairly low gain.

BTW, in RDB Rdb the DB builder can specify placement in such a way that the material required for the join can be in a single database block. That means that the overhead of actually performing the join is CPU overhead, but not disk I/O overhead. Generally speaking, CPU overhead is so low as to not be worth considering in cost based optimization. Received on Mon May 03 2004 - 21:22:58 CEST