From: Justin Pryzby <pryzby@telsasoft.com>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Cc: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Kirill Bychik <kirill.bychik@gmail.com>
Cc: Fujii Masao <masao.fujii@oss.nttdata.com>
Subject: Re: User Interface for WAL usage data
Date: Mon, 6 Apr 2020 11:34:20 -0500
Message-ID: <20200406163420.GE2228@telsasoft.com> (raw)
In-Reply-To: <CAOBaU_YdCWxG3fC5cvL-MeYykRkE_U+BdsnwStniBfqHGq5CuQ@mail.gmail.com>
References: <CAA4eK1+o1Vj4Rso09pKOaKhY8QWTA0gWwCL3TGCi1rCLBBf-QQ@mail.gmail.com>
<20200402054120.GC14618@telsasoft.com>
<20200402.145826.78549992113208057.horikyota.ntt@gmail.com>
<CAA4eK1J0CaomuePkTGG2OBEukeDmLFWQ4kP=+zvBcX324t=EUA@mail.gmail.com>
<CAOBaU_YdCWxG3fC5cvL-MeYykRkE_U+BdsnwStniBfqHGq5CuQ@mail.gmail.com>
On Thu, Apr 02, 2020 at 08:29:31AM +0200, Julien Rouhaud wrote:
> > > "full page records" seems to be showing the number of full page
> > > images, not the record having full page images.
> >
> > I am not sure what exactly is a difference but it is the records
> > having full page images. Julien correct me if I am wrong.
> Obviously previous complaints about the meaning and parsability of
> "full page writes" should be addressed here for consistency.
There's a couple places that say "full page image records" which I think is
language you were trying to avoid. It's the number of pages, not the number of
records, no ? I see explain and autovacuum say what I think is wanted, but
these say the wrong thing? Find attached slightly larger patch.
$ git grep 'image record'
contrib/pg_stat_statements/pg_stat_statements.c: int64 wal_num_fpw; /* # of WAL full page image records generated */
doc/src/sgml/ref/explain.sgml: number of records, number of full page image records and amount of WAL
--
Justin
Attachments:v1-0001-doc-WAL-usage.patch (text/x-diff, 2.8K) download
From 6819c8c61c7fe2294b132a72c3897dc5cb801c4f Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Mon, 6 Apr 2020 11:28:08 -0500
Subject: [PATCH v1] doc: WAL usage
See also:
6b466bf5f2bea0c89fab54eef696bcfc7ecdafd7
33e05f89c53e5a1533d624046bb6fb0da7bb7141
---
contrib/pg_stat_statements/pg_stat_statements.c | 2 +-
doc/src/sgml/pgstatstatements.sgml | 6 +++---
doc/src/sgml/ref/explain.sgml | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.cindex 04abdab904..3bcf34c669 100644--- a/contrib/pg_stat_statements/pg_stat_statements.c+++ b/contrib/pg_stat_statements/pg_stat_statements.c@@ -189,7 +189,7 @@ typedef struct Counters
double blk_write_time; /* time spent writing, in msec */
double usage; /* usage factor */
int64 wal_records; /* # of WAL records generated */
- int64 wal_num_fpw; /* # of WAL full page image records generated */+ int64 wal_num_fpw; /* # of WAL full page images generated */
uint64 wal_bytes; /* total amount of WAL bytes generated */
} Counters;
diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgmlindex 3d26108649..de28016a02 100644--- a/doc/src/sgml/pgstatstatements.sgml+++ b/doc/src/sgml/pgstatstatements.sgml@@ -269,7 +269,7 @@
<entry><type>numeric</type></entry>
<entry></entry>
<entry>
- Total amount of WAL bytes generated by the statement+ Total number of WAL bytes generated by the statement
</entry>
</row>
@@ -278,7 +278,7 @@
<entry><type>bigint</type></entry>
<entry></entry>
<entry>
- Total count of WAL records generated by the statement+ Total number of WAL records generated by the statement
</entry>
</row>
@@ -287,7 +287,7 @@
<entry><type>bigint</type></entry>
<entry></entry>
<entry>
- Total count of WAL full page writes generated by the statement+ Total number of WAL full page writes generated by the statement
</entry>
</row>
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgmlindex 024ede4a8d..4a9f94d7f8 100644--- a/doc/src/sgml/ref/explain.sgml+++ b/doc/src/sgml/ref/explain.sgml@@ -198,7 +198,7 @@ ROLLBACK;
<listitem>
<para>
Include information on WAL record generation. Specifically, include the
- number of records, number of full page image records and amount of WAL+ number of records, number of full page images and number of WAL
bytes generated. In text format, only non-zero values are printed. This
parameter may only be used when <literal>ANALYZE</literal> is also
enabled. It defaults to <literal>FALSE</literal>.
--
2.17.0
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To: pgsql-hackers@postgresql.org
Cc: pryzby@telsasoft.com, rjuju123@gmail.com, amit.kapila16@gmail.com, horikyota.ntt@gmail.com, pgsql-hackers@lists.postgresql.org, dilipbalaut@gmail.com, kirill.bychik@gmail.com, masao.fujii@oss.nttdata.com
Subject: Re: User Interface for WAL usage data
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