Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitb3abca6

Browse files
committed
pgstat: Update docs to match the shared memory stats reality.
This includes removing documentation for stats_temp_directory, addingdocumentation for stats_fetch_consistency, rephrasing references to the statscollector and documenting that starting a cleanly shut down standby will notremove stats anymore. The latter point might require further wordsmithing, itwasn't easy to adjust some of the existing content.Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>Author: Andres Freund <andres@anarazel.de>Reviewed-By: Thomas Munro <thomas.munro@gmail.com>Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>Reviewed-By: "David G. Johnston" <david.g.johnston@gmail.com>Reviewed-By: Lukas Fittl <lukas@fittl.com>Discussion:https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
1 parent76cbf7e commitb3abca6

File tree

9 files changed

+139
-119
lines changed

9 files changed

+139
-119
lines changed

‎doc/src/sgml/backup.sgml

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1036,8 +1036,6 @@ SELECT * FROM pg_backup_stop(wait_for_archive => true);
10361036
<filename>pg_snapshots/</filename>, <filename>pg_stat_tmp/</filename>,
10371037
and <filename>pg_subtrans/</filename> (but not the directories themselves) can be
10381038
omitted from the backup as they will be initialized on postmaster startup.
1039-
If <xref linkend="guc-stats-temp-directory"/> is set and is under the data
1040-
directory then the contents of that directory can also be omitted.
10411039
</para>
10421040

10431041
<para>

‎doc/src/sgml/catalogs.sgml

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -9593,9 +9593,9 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
95939593
<para>
95949594
<xref linkend="view-table"/> lists the system views described here.
95959595
More detailed documentation of each view follows below.
9596-
There are some additional views that provide access tothe results of
9597-
thestatistics collector; they are described in <xref
9598-
linkend="monitoring-stats-views-table"/>.
9596+
There are some additional views that provide access toaccumulated
9597+
statistics; they are described in
9598+
<xreflinkend="monitoring-stats-views-table"/>.
95999599
</para>
96009600

96019601
<para>

‎doc/src/sgml/config.sgml

Lines changed: 32 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -7885,15 +7885,15 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
78857885
<sect1 id="runtime-config-statistics">
78867886
<title>Run-time Statistics</title>
78877887

7888-
<sect2 id="runtime-config-statistics-collector">
7889-
<title>Query and Index Statistics Collector</title>
7888+
<sect2 id="runtime-config-cumulative-statistics">
7889+
<title>CumulativeQuery and Index Statistics</title>
78907890

78917891
<para>
7892-
These parameters control server-wide statisticscollection features.
7893-
Whenstatistics collection isenabled, the data that isproduced can be
7894-
accessed via the<structname>pg_stat</structname> and
7895-
<structname>pg_statio</structname>family of system views.
7896-
Refer to <xref linkend="monitoring"/> for moreinformation.
7892+
These parameters controltheserver-widecumulativestatisticssystem.
7893+
When enabled, the data that iscollected can be accessed via the
7894+
<structname>pg_stat</structname> and <structname>pg_statio</structname>
7895+
family of system views. Refer to <xref linkend="monitoring"/> for more
7896+
information.
78977897
</para>
78987898

78997899
<variablelist>
@@ -8031,22 +8031,37 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
80318031
</listitem>
80328032
</varlistentry>
80338033

8034-
<varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
8035-
<term><varname>stats_temp_directory</varname> (<type>string</type>)
8034+
<varlistentry id="guc-stats-fetch-consistency" xreflabel="stats_fetch_consistency">
8035+
<term><varname>stats_fetch_consistency</varname> (<type>enum</type>)
80368036
<indexterm>
8037-
<primary><varname>stats_temp_directory</varname> configuration parameter</primary>
8037+
<primary><varname>stats_fetch_consistency</varname> configuration parameter</primary>
80388038
</indexterm>
80398039
</term>
80408040
<listitem>
80418041
<para>
8042-
Sets the directory to store temporary statistics data in. This can be
8043-
a path relative to the data directory or an absolute path. The default
8044-
is <filename>pg_stat_tmp</filename>. Pointing this at a RAM-based
8045-
file system will decrease physical I/O requirements and can lead to
8046-
improved performance.
8047-
This parameter can only be set in the <filename>postgresql.conf</filename>
8048-
file or on the server command line.
8042+
Determines the behavior when cumulative statistics are accessed
8043+
multiple times within a transaction. When set to
8044+
<literal>none</literal>, each access re-fetches counters from shared
8045+
memory. When set to <literal>cache</literal>, the first access to
8046+
statistics for an object caches those statistics until the end of the
8047+
transaction unless <function>pg_stat_clear_snapshot()</function> is
8048+
called. When set to <literal>snapshot</literal>, the first statistics
8049+
access caches all statistics accessible in the current database, until
8050+
the end of the transaction unless
8051+
<function>pg_stat_clear_snapshot()</function> is called. The default
8052+
is <literal>cache</literal>.
80498053
</para>
8054+
<note>
8055+
<para>
8056+
<literal>none</literal> is most suitable for monitoring systems. If
8057+
values are only accessed once, it is the most
8058+
efficient. <literal>cache</literal> ensures repeat accesses yield the
8059+
same values, which is important for queries involving
8060+
e.g. self-joins. <literal>snapshot</literal> can be useful when
8061+
interactively inspecting statistics, but has higher overhead,
8062+
particularly if many database objects exist.
8063+
</para>
8064+
</note>
80508065
</listitem>
80518066
</varlistentry>
80528067

‎doc/src/sgml/func.sgml

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -28019,8 +28019,8 @@ SELECT collation for ('foo' COLLATE "de_DE");
2801928019
<para>
2802028020
Requests to log the memory contexts of the backend with the
2802128021
specified process ID. This function can send the request to
28022-
backends and auxiliary processes except logger and statistics
28023-
collector. These memory contextswill be logged at
28022+
backends and auxiliary processes except logger. These memory contexts
28023+
will be logged at
2802428024
<literal>LOG</literal> message level. They will appear in
2802528025
the server log based on the log configuration set
2802628026
(See <xref linkend="runtime-config-logging"/> for more information),

‎doc/src/sgml/glossary.sgml

Lines changed: 18 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -136,17 +136,16 @@
136136
The auxiliary processes consist of <!-- in alphabetical order -->
137137
<!-- NB: In the code, the autovac launcher doesn't use the auxiliary
138138
process scaffolding; however it does behave as one so we list it
139-
here anyway. In addition, loggerand stats collector aren't
140-
connected to shared memory somost code outside postmaster.c
141-
doesn't even consider them "procs" inthe first place.
139+
here anyway. In addition, loggerisn't connected to shared memory so
140+
most code outside postmaster.c doesn't even consider them "procs" in
141+
the first place.
142142
-->
143143
the <glossterm linkend="glossary-autovacuum">autovacuum launcher</glossterm>
144144
(but not the autovacuum workers),
145145
the <glossterm linkend="glossary-background-writer">background writer</glossterm>,
146146
the <glossterm linkend="glossary-checkpointer">checkpointer</glossterm>,
147147
the <glossterm linkend="glossary-logger">logger</glossterm>,
148148
the <glossterm linkend="glossary-startup-process">startup process</glossterm>,
149-
the <glossterm linkend="glossary-stats-collector">statistics collector</glossterm>,
150149
the <glossterm linkend="glossary-wal-archiver">WAL archiver</glossterm>,
151150
the <glossterm linkend="glossary-wal-receiver">WAL receiver</glossterm>
152151
(but not the <glossterm linkend="glossary-wal-sender">WAL senders</glossterm>),
@@ -434,6 +433,21 @@
434433
</glossdef>
435434
</glossentry>
436435

436+
<glossentry id="glossary-cumulative-statistics">
437+
<glossterm>Cumulative Statistics System</glossterm>
438+
<glossdef>
439+
<para>
440+
A system which, if enabled, accumulates statistical information
441+
about the <glossterm linkend="glossary-instance">instance</glossterm>'s
442+
activities.
443+
</para>
444+
<para>
445+
For more information, see
446+
<xref linkend="monitoring-stats"/>.
447+
</para>
448+
</glossdef>
449+
</glossentry>
450+
437451
<glossentry>
438452
<glossterm>Data area</glossterm>
439453
<glosssee otherterm="glossary-data-directory" />
@@ -1563,22 +1577,6 @@
15631577
</glossdef>
15641578
</glossentry>
15651579

1566-
<glossentry id="glossary-stats-collector">
1567-
<glossterm>Stats collector (process)</glossterm>
1568-
<glossdef>
1569-
<para>
1570-
An <glossterm linkend="glossary-auxiliary-proc">auxiliary process</glossterm>
1571-
which, if enabled, receives statistical information
1572-
about the <glossterm linkend="glossary-instance">instance</glossterm>'s
1573-
activities.
1574-
</para>
1575-
<para>
1576-
For more information, see
1577-
<xref linkend="monitoring-stats"/>.
1578-
</para>
1579-
</glossdef>
1580-
</glossentry>
1581-
15821580
<glossentry id="glossary-system-catalog">
15831581
<glossterm>System catalog</glossterm>
15841582
<glossdef>

‎doc/src/sgml/high-availability.sgml

Lines changed: 7 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -2227,12 +2227,13 @@ HINT: You can then restart the server after making the necessary configuration
22272227
</para>
22282228

22292229
<para>
2230-
The statistics collector is active during recovery. All scans, reads, blocks,
2231-
index usage, etc., will be recorded normally on the standby. Replayed
2232-
actions will not duplicate their effects on primary, so replaying an
2233-
insert will not increment the Inserts column of pg_stat_user_tables.
2234-
The stats file is deleted at the start of recovery, so stats from primary
2235-
and standby will differ; this is considered a feature, not a bug.
2230+
The cumulative statistics system is active during recovery. All scans,
2231+
reads, blocks, index usage, etc., will be recorded normally on the
2232+
standby. However, WAL replay will not increment relation and database
2233+
specific counters. I.e. replay will not increment pg_stat_all_tables
2234+
columns (like n_tup_ins), nor will reads or writes performed by the
2235+
startup process be tracked in the pg_statio views, nor will associated
2236+
pg_stat_database columns be incremented.
22362237
</para>
22372238

22382239
<para>

‎doc/src/sgml/maintenance.sgml

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -839,7 +839,7 @@ vacuum insert threshold = vacuum base insert threshold + vacuum insert scale fac
839839
it may be beneficial to lower the table's
840840
<xref linkend="reloption-autovacuum-freeze-min-age"/> as this may allow
841841
tuples to be frozen by earlier vacuums. The number of obsolete tuples and
842-
the number of inserted tuples are obtained from the statisticscollector;
842+
the number of inserted tuples are obtained from thecumulativestatisticssystem;
843843
it is a semi-accurate count updated by each <command>UPDATE</command>,
844844
<command>DELETE</command> and <command>INSERT</command> operation. (It is
845845
only semi-accurate because some information might be lost under heavy

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp