2010/1/28 Tom Lane <t...@sss.pgh.pa.us>: > Pavel Stehule <pavel.steh...@gmail.com> writes: >> in 99.99% the second argument will be a constant. Can we use this >> information and optimize function for this case? > >> The detoast on every row can take some percent from a performance. > > What detoast? There won't be one for a constant, nor even for a > variable in any sane situation --- who's going to be using > multi-kilobyte delimiter values? And if they do, aren't they likely > to run out of memory for the result long before the repeated detoasts > become an interesting problem? You're arguing about a case that > seems quite irrelevant to the real world. >
I asking with get_fn_expr_arg_stable() we are able to fix second parameter without some performance issues. Regards Pavel > 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
