Re: No write stats in pg_statio system views - Mailing list pgsql-hackers

From ITAGAKI Takahiro
Subject Re: No write stats in pg_statio system views
Date
Msg-id 20081107093707.9DD8.52131E4D@oss.ntt.co.jp
Whole thread Raw
In response to No write stats in pg_statio system views  ("Nikhil Sontakke" <nikhil.sontakke@enterprisedb.com>)
List pgsql-hackers
"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




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