No write stats in pg_statio system views

"Nikhil Sontakke" <nikhil.sontakke@enterprisedb.com> wrote:

What is the reason for not having heap_blks_write kind of stats in the
pg_statio system views? Is it because bgwriter does the writing (we do have
bg stats there) most of the times? Wouldn't the write stats help to get the
complete IO picture for the relation?

That's because we don't have relfilenode-based statistics.
We have only relation oid based statistics and the oid information
is not available on writing (including bgwriter).

If we can change statistics to be relfilenode-based,
heap_blks_write would be available. It might be worth trying,
but some works are needed.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center