Re: Missed bet in toaster routines
Tom Lane wrote:
Wouldn't it be a win for heap_tuple_toast_attrs() to fall out quickly
if the tuple contains no varlena attributes? I'm thinking of adding
a test like/* Nothing to do if tuple contains no varlena fields */
if ((newtup && !HeapTupleAllFixed(newtup)) ||
(oldtup && !HeapTupleAllFixed(oldtup)))
/* do existing processing */This is a pretty cheap test (just checking a header flag) and saves lots
of useless scanning when it succeeds.
Why sure it would. That code is quite frequently called.
Jan
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Jan Wieck <JanWieck@Yahoo.com> writes:
Tom Lane wrote:
Wouldn't it be a win for heap_tuple_toast_attrs() to fall out quickly
if the tuple contains no varlena attributes?
Why sure it would. That code is quite frequently called.
I take it back --- the short-circuit test already exists, but it's at
the call sites rather than in tuptoaster.c.
However, it looks like we can tighten the tests a bit. For instance
heap_delete invokes the toaster if HeapTupleHasExtended, whereas it
seems to me it'd be sufficient to check HasExternal --- we don't care
about deleting compressed-in-line stuff, do we?
regards, tom lane