Re: One sequence or many sequences?
Date: Thu, 26 Jun 2008 10:53:43 -0400
Mark D Powell wrote:
> The practice of using a separate sequence for every table is wasteful
> and unnecessary. It is must more efficient to share a single sequence
> among a collection of low insert rate tables. This practice will
> reduce the number of times Oracle has to flush a sequence from the
> sequence cash to make room for another sequence
Couple of thoughts on this:
* If I have 100 sequences with cache 20 I run out of cache every 20 NEXTVALs somewhere on average. If I have one sequence with cache 20 I run out of cache every 20 NEXTVALs just the same. The difference is in the memory requirement. And of course I can play with the CACHE size. * One sequence means bigger numbers. Bigger numbers mean more space (more digits).
Perhaps that is negligible for a wide row, perhaps not.
I think it boils down to mostly taste...
-- Serge Rielau DB2 Solutions Development IBM Toronto LabReceived on Thu Jun 26 2008 - 09:53:43 CDT