From: | Itagaki Takahiro <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp> |
---|---|
To: | Euler Taveira de Oliveira <euler(at)timbira(dot)com> |
Cc: | Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Buffer usage in EXPLAIN and pg_stat_statements (review) |
Date: | 2009-10-01 02:40:27 |
Message-ID: | 20091001112006.9C36.52131E4D@oss.ntt.co.jp |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Euler Taveira de Oliveira <euler(at)timbira(dot)com> wrote:
> > But there are some confusions in postgres; ReadBufferCount and
> > BufferHitCount are used for "get" and "hit", but "heap_blks_read"
> > and "heap_blks_hit" are used for "read" and "hit" in pg_statio_all_tables.
> I see. :(
I fixed the confusions of get, hit and read in your patch.
long num_hit = ReadBufferCount + ReadLocalBufferCount;
long num_read = num_hit - BufferHitCount - LocalBufferHitCount;
should be
long num_get = ReadBufferCount + ReadLocalBufferCount;
long num_hit = BufferHitCount + LocalBufferHitCount;
long num_read = num_get - num_hit;
ReadBufferCount means "number of buffer access" :(
Patch attached.
Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center
Attachment | Content-Type | Size |
---|---|---|
buffer_usage_20091001.patch | application/octet-stream | 22.6 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Mark Mielke | 2009-10-01 03:09:02 | Re: Use "samehost" by default in pg_hba.conf? |
Previous Message | Robert Haas | 2009-10-01 02:39:01 | Re: Use "samehost" by default in pg_hba.conf? |