Re: Lowering the ever-growing heap->pd_lower - Mailing list pgsql-hackers

Hi,

On 2022-04-04 19:24:22 -0700, Peter Geoghegan wrote:
> We should definitely increase MaxHeapTuplesPerPage before too long,
> for a variety of reasons that I have talked about in the past. Its
> current value is 291 on all mainstream platforms, a value that's
> derived from accidental historic details -- which predate HOT.

I'm on-board with that - but I think we should rewrite a bunch of places that
use MaxHeapTuplesPerPage sized-arrays on the stack first. It's not great using
several KB of stack at the current the current value already (*), but if it grows
further...

Greetings,

Andres Freund


* lazy_scan_prune() has
    OffsetNumber deadoffsets[MaxHeapTuplesPerPage];
    xl_heap_freeze_tuple frozen[MaxHeapTuplesPerPage];
which already works out to 4074 bytes.