Re: In an RDBMS, what does "Data" mean?
Date: Sat, 19 Jun 2004 09:06:24 -0400
Message-ID: <M-6dnRspMqlopEndRVn-hQ_at_comcast.com>
"Tony" <andrewst_at_onetel.net.uk> wrote in message
news:c0e3f26e.0406190351.dcb2cdc_at_posting.google.com...
> "Anthony W. Youngman" <wol_at_thewolery.demon.co.uk> wrote in message
news:<L4l1l0HM7y0AFwZd_at_thewolery.demon.co.uk>...
> > Was it Knuth that said "premature optimisation is the worst evil"?
>
> I don't know, but YOU are the one who wants to optimise prematurely,
> i.e. while designing the database. The relationalists prefer to
> optimise at the last possible moment, i.e. when we know what the query
> is.
Not only when we know the query, but also when we know, approximately, the data volumes.
Given that access strategy costs are non linear, this is an important input to optimization. Received on Sat Jun 19 2004 - 15:06:24 CEST