Hi Kirill,
> Changing this constant will result in an overwhelming increase of
> memory consumption for instances that work with a large number of
> connections (
> max_connections ~ 1e4) for zero benefit.
No, it's not that bad.
1) With this being allocated in the bss segment,
the RAM will only be actually be provided on _first use_ --
so processes that only ever work with small queries will see no
difference.
2) With temp_buffers' default of 8MB, work_mem using 4MB, etc.,
using an additional 256kB RAM to 2MB _when needed_ is a good deal
for about 7% performance improvements.