Re: Assert Levels

Greg Smith <gsmith@gregsmith.com> writes:
> The next time I'm doing some performance testing I'll try to quantify how 
> much damage the expensive ones do by playing with pg_config_manual.h. 
> Normally I'm testing with 1GB+ of shared_buffers which makes the current 
> assert scheme unusable.

There is a commit-time scan of the buffers for the sole purpose of
asserting a few things about their state.  That's one of the things
we'd need to turn off for a "cheap asserts only" mode I think.

If you want to try to quantify what "cheap asserts" might do, you
should pull out the #ifdef USE_ASSERT_CHECKING code here:check_list_invariants in list.cthe loops in AtEOXact_Buffers
andAtEOXact_LocalBuffersthe loop in AtEOXact_CatCachethe test that makes AtEOXact_RelationCache scan the relcache
evenwhen !need_eoxact_work
 
in addition to the memory-related stuff.
        regards, tom lane