On 2014-06-29 19:52:23 -0400, Tom Lane wrote:
> Andres Freund <andres@2ndquadrant.com> writes:
> > Why aren't we delaying allocations in e.g. AtStart_Inval(),
> > AfterTriggerBeginXact() to when the data structures are acutally used?
>
> Aren't we? Neither of those would be doing much work certainly.
They are perhaps not doing much in absolute terms, but it's a fair share
of the processing overhead for simple statements. AfterTriggerBeginXact()
is called unconditionally from StartTransaction() and does three
MemoryContextAlloc()s. AtStart_Inval() one.
I think they should just be initialized whenever the memory is used?
Doesn't look too complicated to me.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services