Ilya Matveychikov <matvejchikov@gmail.com> writes:
> Seems that accounting of insertions with `n_tup_ins` not correct in
> case of insertion errors cause by constraints checking (duplicate key
> value violates unique constraint):
You already found one of the many code comments indicating that this is
the intended behavior:
> CODE REFERENCE (src/backend/postmaster/pgstat.c)
> /* count attempted actions regardless of commit/abort */
> So, is this behavior normal or probably needs to be fixed?
No, it's not a bug, and it's not going to be fixed. For many of the
intended applications of those counts (e.g, determining whether
autovacuum/autoanalyze is needed), this is the correct behavior
and ignoring actions of failed transactions would be incorrect.
The live/dead tuple counts do attempt to take transaction success
into account; perhaps looking at those would be more helpful for
your use-case?
regards, tom lane