On 2013-06-14 15:49:31 +0100, Dean Rasheed wrote: > On 14 June 2013 15:19, Stephen Frost <sfr...@snowman.net> wrote: > > * Andrew Dunstan (and...@dunslane.net) wrote: > >> I'd rather go the other way, processing the records without having > >> to process them otherwise at all. Turning things into text must slow > >> things down, surely. > > > > That's certainly an interesting idea also.. > > > > md5_agg(record) ? > > Yes, I like it.
It's more complex than just memcmp()ing HeapTupleData though. At least if the Datum contains varlena columns there's so many different representations (short, long, compressed, external, external compressed) of the same data that a md5 without normalizing that wouldn't be very interesting. So you would at least need a normalizing version of toast_flatten_tuple() that also deals with short/long varlenas. But even after that, you would still need to deal with Datums that can have different representation (like short numerics, old style hstore, ...). It might be more realistic to use the binary output functions, but I am not sure whether all of those are sufficiently reproduceable. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
