While fixing the recent unpleasantness over parallel polymorphic aggregates, I discovered that count_agg_clauses_walker's consideration of an aggregate argument's typmod in estimating transition space consumption has been broken since commit 34d26872e (which changed Aggref.args from a simple expression list to a list of TargetEntry). It had been looking at "exprTypmod((Node *) linitial(aggref->args))", and nobody taught it that there was now a TargetEntry in the way that it needed to look through to get a correct answer.
Ordinarily I'd just summarily back-patch a fix, but that commit shipped in 9.0, which means it's been broken a long time. I'm worried that back-patching a change might be more likely to destabilize plan choices than to do anything anybody's happy about. Thoughts? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers