(2011/12/13 18:57), Albe Laurenz wrote: > Maybe I'm missing something, but if pushdown worked as follows: > > - Push down only system functions and operators on system types. > - Only push down what is guaranteed to work.
Oh, I didn't care whether system data types. Indeed user defined types would not be safe to push down. > then the only things we would miss out on are encoding- or > collation-sensitive string operations. > > Is that loss so big that it warrants a lot of effort? It depends on the definition of "collation-sensitive". If we define it as "all operations which might handle any collation-sensitive element", all functions/operators which take any of character data types (text, varchar, bpchar, sql_identifier, etc.) are unable to be pushed down. Regards, -- Shigeru Hanada -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers