Kevin Grittner wrote: > Note that the 150 disk writes were for the CREATE and the DROP. Does > that mean that we'd actually shave 84 of 150 writes?
Hmm, you'd shave more than 42 but not 84, because index entries are not deleted until a later vacuum. (I'd say about 56 -- 42 plus the 14 heap deletions). > Also, if you're looking to account for all the writes, it's worth > noting that my test declared a one-column primary key (on an integer > column) in the CREATE TEMPORARY TABLE statement. That probably makes up for the extra few writes that I didn't see in my quick test. > In suggesting this enhancement, my hope is that each session could > check for a referenced table as a temporary in RAM before going to the > system tables, in a manner vaguely similar to how space reserved by > the temp_buffers GUC is used for temp table data. I, of course, am > suggesting this from a position of blissful ignorance of the actual > complexity of making such a change. Right -- I don't expect we can make use of such an idea readily. Not creating unnecessary pg_attribute entries for system columns is probably a lot easier to do. The idea of uncatalogued temp tables has been suggested and rejected several times in the past. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers