Re: proposal - patch: psql - sort_by_size

Hello Jeremy,

>> Comments, notes?
>
> One oddity about pg_relation_size and pg_table_size is that they can be
> easily blocked by user activity. In fact it happens to us often in
> reporting environments and we have instead written different versions of
> them that avoid the lock contention and still give "close enough" results.
>
> This blocking could result in quite unexpected behavior, that someone uses
> your proposed command and it never returns. Has that been considered as a
> reality at least to be documented?

ISTM that it does not change anything wrt the current behavior because of
the prudent lazy approach: the sorting is *only* performed when the size
is already available in one of the printed column.

Maybe the more general question could be "is there a caveat somewhere that
when doing \d.+ a user may have issues with locks because of the size
computations?".

--
Fabien.