Re: Semantics of PostgreSQL Server Log Stats

Camilo Porto wrote:
>
> Hello,
>
> I would like to better understand the semantics of the statistics shown in PostgreSQL Logs. For example, in the
report:
>
> DETAIL:  ! system usage stats:
>         !       0.000100 elapsed 0.000000 user 0.000000 system sec
>         !       [0.016997 user 0.006998 sys total]
>         !       0/0 [0/0] filesystem blocks in/out
>         !       0/2 [0/1301] page faults/reclaims, 0 [0] swaps
>         !       0 [0] signals rcvd, 0/0 [0/0] messages rcvd/sent
>         !       0/0 [6/20] voluntary/involuntary context switches

The above are from getrusage().  See the getrusage manual page.

>         ! buffer usage stats:
>         !       Shared blocks:          1 read,          0 written, buffer hit rate = 0.00%
>         !       Local  blocks:          0 read,          0 written, buffer hit rate = 0.00%
>         !       Direct blocks:          0 read,          0 written
>
> What each element of this report mean?

This outlines the shared/local buffer I/O and file system I/O performed.

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  Bruce Momjian  <bruce@momjian.us>          http://momjian.us
  EnterpriseDB                               http://www.enterprisedb.com

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