On Thu, Jan 16, 2020 at 10:27:01AM -0500, Tom Lane wrote:
>Andres Freund <andres@anarazel.de> writes:
>> ... I thought you were asking whether
>> any additional memory could just be avoided...
>
>Well, I was kind of wondering that, but if it's not practical then
>preallocating the space instead will do.
>
I don't think it's practical to rework the checks in a way that would
not require allocations. Maybe it's possible, but I think it's not worth
the extra complexity.
The attached fix should do the trick - it pre-allocates the space when
creating the context. There is a bit of complexity because we want to
allocate the space as part of the context header, but nothin too bad. We
might optimize it a bit by using a regular bitmap (instead of just an
array of bools), but I haven't done that.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
