On 28 December 2012 11:27, Amit Kapila <amit.kap...@huawei.com> wrote:
>> * TOAST is not handled at all. No comments about it, nothing. Does >> that mean it hasn't been considered? Or did we decide not to care in >> this release? > >> Presumably that means we are comparing toast pointers >> byte by byte to see if they are the same? > > Yes, currently this patch is doing byte by byte comparison for toast > pointers. I shall add comment. > In future, we can evaluate if further optimizations can be done. Just a comment to say that the comparison takes place after TOASTed columns have been removed. TOAST is already optimised for whole value UPDATE anyway, so that is the right place to produce the delta. It does make me think that we can further optimise TOAST by updating only the parts of a toasted datum that have changed. That will be useful for JSON and XML applications that change only a portion of large documents. -- Simon Riggs 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
