"Jim C. Nasby" <[EMAIL PROTECTED]> writes:
> On Sun, Oct 02, 2005 at 09:46:07PM -0400, Tom Lane wrote:
>> 1. A cross-table index would need to store a table OID as well as the
>> existing block/offset information in order to tell you what an entry is
>> pointing at.
> Wouldn't it make more sense to use a smaller pointer to a table of OIDs
> that that index covers?
Smaller than what? Don't tell me you want to restrict how many tables a
cross-table index can handle :-(
In any case, the gain from doing that would be exactly zero because of
alignment considerations: the size of an index tuple header really has
to be a multiple of MAXALIGN.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
