Re: Reducing the chunk header sizes on all memory context types

Andres Freund <andres@anarazel.de> writes:
> I think it's fine, given that we can change this at any time, but it's
> probably worth to explicitly agree that this will for now restrict us to 8
> context methods?

Do we really need it to be that tight?  I know we only have 3 methods today,
but 8 doesn't seem that far away.  If there were six bits reserved for
this I'd be happier.

>> # We also add a restriction that block sizes for all 3 of the memory
>> # allocators cannot be 1GB or larger.  We would be unable to store the
>> # number of bytes that the block is offset from the chunk stored beyond this
>> #1GB boundary on any block that was larger than 1GB.

Losing MemoryContextAllocHuge would be very bad, so I assume this comment
is not telling the full truth.

            regards, tom lane