Re: Can blob be compared?

ctcgag_at_hotmail.com wrote:
>
> Simon Hall <Simon.Hall_at_logicacmg.com> wrote:
> >
> > Just a thought - when you create (or change) the blob create a checksum.
> > Then when you want to compare blobs, compare the length and the checksum
> > instead. Only if both match do you then need to compare the blobs byte
> > for byte.
>
> Would it be possible to do this in a single query? I.E, does the where
> logic of a query apply short-circuiting logic, and if so is the order
> of evaluation controllable (or even predictable)?
>

Not directly as the order of evaluation is up to the optimiser (although there may be hints that stop this, anyone?). It should be possible to write a function to hard wire the logic and use that in the where clause though.

Simon Received on Tue Apr 08 2003 - 04:51:07 CDT