So while poking at a recent example from Marc Cousin (hundreds of tables
each with 1000 attributes) I observed that a simple ANALYZE would bloat
the backend process to the tune of several hundred megabytes. I think
there is a leak in CacheMemoryContext, but haven't tracked it down yet.
But I also noticed that tens of megabytes were disappearing into "Attopt
cache", and after reading the code to see what the heck that was, I am
wondering what the justification for having it is at all. In the
presumably normal case where the attribute hasn't got options, all it's
saving us is a syscache access, which is probably not noticeably more
expensive than the hash lookup. In the case where there is an option,
it's saving us an attribute_reloptions() call, but it's not apparent
to me that that's so expensive as to justify putting a cache in front
of it, especially not if we're going to do a palloc cycle anyway.
Did anybody do any performance measurements to demonstrate that this
code has a reason to live? Because if I don't see some, I'm going
to rip it out.
regards, tom lane