> update ta set ta.b =
> (select tb.b from tb where tb.a = ta.a)
>
> generates
>
> PLAN (TB NATURAL)
> PLAN (TA NATURAL)
>
> Of course without any indexes this could take
> some time, but why ?

I can understand that IB does not use an index for TA - it has to
process all records anyway so an index would only add to the work
required.

I dont know about TB. Perhaps you should ask on the IB_Support list.

(The other suggestion is to setup inside a stored procedure and see if
it all seems to work as expected - and faster - in that situation.)


Geoff Worboys
Telesis Computing