Tom Lane wrote:
Is the value you are fetching from the geography table large enough to be toasted? I'm thinking you might be looking at the cost of repeated de-toastings.
Yeah, it's a fairly large geometry field so it will definitely be getting toasted. So is it a case of with the mcatest function in place, we're effectively caching the de-TOASTED value?
BTW, that mcatest function is buggy --- it's not copying the last 4 bytes of the source value. I don't know enough about PostGIS data types to know what effect that would have.
It would probably lose that last point in the coordinate sequence, but nothing major. I've removed the -VARHDRSZ part just to check and it doesn't make any difference.
Many thanks, Mark. -- Mark Cave-Ayland Sirius Corporation - The Open Source Experts http://www.siriusit.co.uk T: +44 870 608 0063 -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
