From: Tom Lane <tgl@sss.pgh.pa.us>
To: pgsql-docs@lists.postgresql.org
Subject: Re: Remaining PDF layout issues
Date: Tue, 12 May 2020 01:10:06 -0400
Message-ID: <26961.1589260206@sss.pgh.pa.us> (raw)
In-Reply-To: <10190.1589248770@sss.pgh.pa.us>
References: <6916.1589146280@sss.pgh.pa.us>
<10190.1589248770@sss.pgh.pa.us>
I wrote:
>> Table 27.4 is annoying: it could be made to work, just barely, with some
>> hacking of the column widths and a &zwsp; or two. But it's not stable
>> text so I have little faith in the longevity of such a solution,
>> especially if people keep on inventing long wait event names. I also
>> find it not very readable, even in a wide window. The first idea that
>> comes to mind is to split it into multiple tables, one per "Wait Event
>> Type", so that we don't need the lefthand column.
Here's an attempt at doing it that way. I think this might be a better
answer, although it's still subject to problems if anyone's logorrhea gets
any worse in naming wait conditions: "SerializablePredicateLockListLock"
is still going to force manually tweaking the column widths.
I sorted the names here, too.
regards, tom lane
Attachments:
[text/x-diff] fix-wait-event-table-2.patch (86.3K, ../26961.1589260206@sss.pgh.pa.us/2-fix-wait-event-table-2.patch)
download | inline diff:diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgmlindex 579ccd3..64fc0e0 100644--- a/doc/src/sgml/monitoring.sgml+++ b/doc/src/sgml/monitoring.sgml@@ -724,86 +724,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
<entry><structfield>wait_event_type</structfield></entry>
<entry><type>text</type></entry>
<entry>The type of event for which the backend is waiting, if any;
- otherwise NULL. Possible values are:- <itemizedlist>- <listitem>- <para>- <literal>LWLock</literal>: The backend is waiting for a lightweight lock.- Each such lock protects a particular data structure in shared memory.- <literal>wait_event</literal> will contain a name identifying the purpose- of the lightweight lock. (Some locks have specific names; others- are part of a group of locks each with a similar purpose.)- </para>- </listitem>- <listitem>- <para>- <literal>Lock</literal>: The backend is waiting for a heavyweight lock.- Heavyweight locks, also known as lock manager locks or simply locks,- primarily protect SQL-visible objects such as tables. However,- they are also used to ensure mutual exclusion for certain internal- operations such as relation extension. <literal>wait_event</literal> will- identify the type of lock awaited.- </para>- </listitem>- <listitem>- <para>- <literal>BufferPin</literal>: The server process is waiting to access to- a data buffer during a period when no other process can be- examining that buffer. Buffer pin waits can be protracted if- another process holds an open cursor which last read data from the- buffer in question.- </para>- </listitem>- <listitem>- <para>- <literal>Activity</literal>: The server process is idle. This is used by- system processes waiting for activity in their main processing loop.- <literal>wait_event</literal> will identify the specific wait point.- </para>- </listitem>- <listitem>- <para>- <literal>Extension</literal>: The server process is waiting for activity- in an extension module. This category is useful for modules to- track custom waiting points.- </para>- </listitem>- <listitem>- <para>- <literal>Client</literal>: The server process is waiting for some activity- on a socket from user applications, and that the server expects- something to happen that is independent from its internal processes.- <literal>wait_event</literal> will identify the specific wait point.- </para>- </listitem>- <listitem>- <para>- <literal>IPC</literal>: The server process is waiting for some activity- from another process in the server. <literal>wait_event</literal> will- identify the specific wait point.- </para>- </listitem>- <listitem>- <para>- <literal>Timeout</literal>: The server process is waiting for a timeout- to expire. <literal>wait_event</literal> will identify the specific wait- point.- </para>- </listitem>- <listitem>- <para>- <literal>IO</literal>: The server process is waiting for a IO to complete.- <literal>wait_event</literal> will identify the specific wait point.- </para>- </listitem>- </itemizedlist>+ otherwise NULL. See <xref linkend="wait-event-table"/>.
</entry>
</row>
<row>
<entry><structfield>wait_event</structfield></entry>
<entry><type>text</type></entry>
<entry>Wait event name if backend is currently waiting, otherwise NULL.
- See <xref linkend="wait-event-table"/> for details.+ See <xref linkend="wait-event-activity-table"/> through+ <xref linkend="wait-event-timeout-table"/>.
</entry>
</row>
<row>
@@ -890,931 +819,1186 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser
</tgroup>
</table>
- <para>- The <structname>pg_stat_activity</structname> view will have one row- per server process, showing information related to- the current activity of that process.- </para>+ <para>+ The <structname>pg_stat_activity</structname> view will have one row+ per server process, showing information related to+ the current activity of that process.+ </para>++ <note>+ <para>+ The <structfield>wait_event</structfield> and <structfield>state</structfield> columns are+ independent. If a backend is in the <literal>active</literal> state,+ it may or may not be <literal>waiting</literal> on some event. If the state+ is <literal>active</literal> and <structfield>wait_event</structfield> is non-null, it+ means that a query is being executed, but is being blocked somewhere+ in the system.+ </para>+ </note>++ <table id="wait-event-table">+ <title>Wait Event Types</title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry>Wait Event Type</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>Activity</literal></entry>+ <entry>The server process is idle. This is used by+ system processes waiting for activity in their main processing loop.+ <literal>wait_event</literal> will identify the specific wait point.+ See <xref linkend="wait-event-activity-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>BufferPin</literal></entry>+ <entry>The server process is waiting to access to+ a data buffer during a period when no other process can be+ examining that buffer. Buffer pin waits can be protracted if+ another process holds an open cursor which last read data from the+ buffer in question. See <xref linkend="wait-event-bufferpin-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>Client</literal></entry>+ <entry>The server process is waiting for some activity+ on a socket from user applications, and that the server expects+ something to happen that is independent from its internal processes.+ <literal>wait_event</literal> will identify the specific wait point.+ See <xref linkend="wait-event-client-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>Extension</literal></entry>+ <entry>The server process is waiting for activity+ in an extension module. This category is useful for modules to+ track custom waiting points.+ See <xref linkend="wait-event-extension-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>IO</literal></entry>+ <entry>The server process is waiting for a IO to complete.+ <literal>wait_event</literal> will identify the specific wait point.+ See <xref linkend="wait-event-io-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>IPC</literal></entry>+ <entry>The server process is waiting for some activity+ from another process in the server. <literal>wait_event</literal> will+ identify the specific wait point.+ See <xref linkend="wait-event-ipc-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>Lock</literal></entry>+ <entry>The backend is waiting for a heavyweight lock.+ Heavyweight locks, also known as lock manager locks or simply locks,+ primarily protect SQL-visible objects such as tables. However,+ they are also used to ensure mutual exclusion for certain internal+ operations such as relation extension. <literal>wait_event</literal>+ will identify the type of lock awaited.+ See <xref linkend="wait-event-lock-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>LWLock</literal></entry>+ <entry> The backend is waiting for a lightweight lock.+ Each such lock protects a particular data structure in shared memory.+ <literal>wait_event</literal> will contain a name identifying the purpose+ of the lightweight lock. (Some locks have specific names; others+ are part of a group of locks each with a similar purpose.)+ See <xref linkend="wait-event-lwlock-table"/>.+ </entry>+ </row>+ <row>+ <entry><literal>Timeout</literal></entry>+ <entry>The server process is waiting for a timeout+ to expire. <literal>wait_event</literal> will identify the specific wait+ point. See <xref linkend="wait-event-timeout-table"/>.+ </entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-activity-table">+ <title>Wait Events of Type <literal>Activity</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>Activity</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>ArchiverMain</literal></entry>+ <entry>Waiting in main loop of the archiver process.</entry>+ </row>+ <row>+ <entry><literal>AutoVacuumMain</literal></entry>+ <entry>Waiting in main loop of autovacuum launcher process.</entry>+ </row>+ <row>+ <entry><literal>BgWriterHibernate</literal></entry>+ <entry>Waiting in background writer process, hibernating.</entry>+ </row>+ <row>+ <entry><literal>BgWriterMain</literal></entry>+ <entry>Waiting in main loop of background writer process background+ worker.</entry>+ </row>+ <row>+ <entry><literal>CheckpointerMain</literal></entry>+ <entry>Waiting in main loop of checkpointer process.</entry>+ </row>+ <row>+ <entry><literal>LogicalApplyMain</literal></entry>+ <entry>Waiting in main loop of logical apply process.</entry>+ </row>+ <row>+ <entry><literal>LogicalLauncherMain</literal></entry>+ <entry>Waiting in main loop of logical launcher process.</entry>+ </row>+ <row>+ <entry><literal>PgStatMain</literal></entry>+ <entry>Waiting in main loop of the statistics collector process.</entry>+ </row>+ <row>+ <entry><literal>RecoveryWalStream</literal></entry>+ <entry>Waiting for WAL from a stream at recovery.</entry>+ </row>+ <row>+ <entry><literal>SysLoggerMain</literal></entry>+ <entry>Waiting in main loop of syslogger process.</entry>+ </row>+ <row>+ <entry><literal>WalReceiverMain</literal></entry>+ <entry>Waiting in main loop of WAL receiver process.</entry>+ </row>+ <row>+ <entry><literal>WalSenderMain</literal></entry>+ <entry>Waiting in main loop of WAL sender process.</entry>+ </row>+ <row>+ <entry><literal>WalWriterMain</literal></entry>+ <entry>Waiting in main loop of WAL writer process.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-bufferpin-table">+ <title>Wait Events of Type <literal>BufferPin</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>BufferPin</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>BufferPin</literal></entry>+ <entry>Waiting to acquire a pin on a buffer.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-client-table">+ <title>Wait Events of Type <literal>Client</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>Client</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>ClientRead</literal></entry>+ <entry>Waiting to read data from the client.</entry>+ </row>+ <row>+ <entry><literal>ClientWrite</literal></entry>+ <entry>Waiting to write data to the client.</entry>+ </row>+ <row>+ <entry><literal>GSSOpenServer</literal></entry>+ <entry>Waiting to read data from the client while establishing the GSSAPI+ session.</entry>+ </row>+ <row>+ <entry><literal>LibPQWalReceiverConnect</literal></entry>+ <entry>Waiting in WAL receiver to establish connection to remote+ server.</entry>+ </row>+ <row>+ <entry><literal>LibPQWalReceiverReceive</literal></entry>+ <entry>Waiting in WAL receiver to receive data from remote server.</entry>+ </row>+ <row>+ <entry><literal>SSLOpenServer</literal></entry>+ <entry>Waiting for SSL while attempting connection.</entry>+ </row>+ <row>+ <entry><literal>WalReceiverWaitStart</literal></entry>+ <entry>Waiting for startup process to send initial data for streaming+ replication.</entry>+ </row>+ <row>+ <entry><literal>WalSenderWaitForWAL</literal></entry>+ <entry>Waiting for WAL to be flushed in WAL sender process.</entry>+ </row>+ <row>+ <entry><literal>WalSenderWriteData</literal></entry>+ <entry>Waiting for any activity when processing replies from WAL+ receiver in WAL sender process.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-extension-table">+ <title>Wait Events of Type <literal>Extension</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>Extension</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>Extension</literal></entry>+ <entry>Waiting in an extension.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-io-table">+ <title>Wait Events of Type <literal>IO</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>IO</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>BufFileRead</literal></entry>+ <entry>Waiting for a read from a buffered file.</entry>+ </row>+ <row>+ <entry><literal>BufFileWrite</literal></entry>+ <entry>Waiting for a write to a buffered file.</entry>+ </row>+ <row>+ <entry><literal>ControlFileRead</literal></entry>+ <entry>Waiting for a read from the control file.</entry>+ </row>+ <row>+ <entry><literal>ControlFileSync</literal></entry>+ <entry>Waiting for the control file to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>ControlFileSyncUpdate</literal></entry>+ <entry>Waiting for an update to the control file to reach stable+ storage.</entry>+ </row>+ <row>+ <entry><literal>ControlFileWrite</literal></entry>+ <entry>Waiting for a write to the control file.</entry>+ </row>+ <row>+ <entry><literal>ControlFileWriteUpdate</literal></entry>+ <entry>Waiting for a write to update the control file.</entry>+ </row>+ <row>+ <entry><literal>CopyFileRead</literal></entry>+ <entry>Waiting for a read during a file copy operation.</entry>+ </row>+ <row>+ <entry><literal>CopyFileWrite</literal></entry>+ <entry>Waiting for a write during a file copy operation.</entry>+ </row>+ <row>+ <entry><literal>DSMFillZeroWrite</literal></entry>+ <entry>Waiting to write zero bytes to a dynamic shared memory backing+ file.</entry>+ </row>+ <row>+ <entry><literal>DataFileExtend</literal></entry>+ <entry>Waiting for a relation data file to be extended.</entry>+ </row>+ <row>+ <entry><literal>DataFileFlush</literal></entry>+ <entry>Waiting for a relation data file to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>DataFileImmediateSync</literal></entry>+ <entry>Waiting for an immediate synchronization of a relation data file to+ stable storage.</entry>+ </row>+ <row>+ <entry><literal>DataFilePrefetch</literal></entry>+ <entry>Waiting for an asynchronous prefetch from a relation data+ file.</entry>+ </row>+ <row>+ <entry><literal>DataFileRead</literal></entry>+ <entry>Waiting for a read from a relation data file.</entry>+ </row>+ <row>+ <entry><literal>DataFileSync</literal></entry>+ <entry>Waiting for changes to a relation data file to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>DataFileTruncate</literal></entry>+ <entry>Waiting for a relation data file to be truncated.</entry>+ </row>+ <row>+ <entry><literal>DataFileWrite</literal></entry>+ <entry>Waiting for a write to a relation data file.</entry>+ </row>+ <row>+ <entry><literal>LockFileAddToDataDirRead</literal></entry>+ <entry>Waiting for a read while adding a line to the data directory lock+ file.</entry>+ </row>+ <row>+ <entry><literal>LockFileAddToDataDirSync</literal></entry>+ <entry>Waiting for data to reach stable storage while adding a line to the+ data directory lock file.</entry>+ </row>+ <row>+ <entry><literal>LockFileAddToDataDirWrite</literal></entry>+ <entry>Waiting for a write while adding a line to the data directory+ lock file.</entry>+ </row>+ <row>+ <entry><literal>LockFileCreateRead</literal></entry>+ <entry>Waiting to read while creating the data directory lock+ file.</entry>+ </row>+ <row>+ <entry><literal>LockFileCreateSync</literal></entry>+ <entry>Waiting for data to reach stable storage while creating the data+ directory lock file.</entry>+ </row>+ <row>+ <entry><literal>LockFileCreateWrite</literal></entry>+ <entry>Waiting for a write while creating the data directory lock+ file.</entry>+ </row>+ <row>+ <entry><literal>LockFileReCheckDataDirRead</literal></entry>+ <entry>Waiting for a read during recheck of the data directory lock+ file.</entry>+ </row>+ <row>+ <entry><literal>LogicalRewriteCheckpointSync</literal></entry>+ <entry>Waiting for logical rewrite mappings to reach stable storage+ during a checkpoint.</entry>+ </row>+ <row>+ <entry><literal>LogicalRewriteMappingSync</literal></entry>+ <entry>Waiting for mapping data to reach stable storage during a logical+ rewrite.</entry>+ </row>+ <row>+ <entry><literal>LogicalRewriteMappingWrite</literal></entry>+ <entry>Waiting for a write of mapping data during a logical+ rewrite.</entry>+ </row>+ <row>+ <entry><literal>LogicalRewriteSync</literal></entry>+ <entry>Waiting for logical rewrite mappings to reach stable+ storage.</entry>+ </row>+ <row>+ <entry><literal>LogicalRewriteTruncate</literal></entry>+ <entry>Waiting for truncate of mapping data during a logical+ rewrite.</entry>+ </row>+ <row>+ <entry><literal>LogicalRewriteWrite</literal></entry>+ <entry>Waiting for a write of logical rewrite mappings.</entry>+ </row>+ <row>+ <entry><literal>ProcSignalBarrier</literal></entry>+ <entry>Waiting for a barrier event to be processed by all+ backends.</entry>+ </row>+ <row>+ <entry><literal>RelationMapRead</literal></entry>+ <entry>Waiting for a read of the relation map file.</entry>+ </row>+ <row>+ <entry><literal>RelationMapSync</literal></entry>+ <entry>Waiting for the relation map file to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>RelationMapWrite</literal></entry>+ <entry>Waiting for a write to the relation map file.</entry>+ </row>+ <row>+ <entry><literal>ReorderBufferRead</literal></entry>+ <entry>Waiting for a read during reorder buffer management.</entry>+ </row>+ <row>+ <entry><literal>ReorderBufferWrite</literal></entry>+ <entry>Waiting for a write during reorder buffer management.</entry>+ </row>+ <row>+ <entry><literal>ReorderLogicalMappingRead</literal></entry>+ <entry>Waiting for a read of a logical mapping during reorder buffer+ management.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotRead</literal></entry>+ <entry>Waiting for a read from a replication slot control file.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotRestoreSync</literal></entry>+ <entry>Waiting for a replication slot control file to reach stable storage+ while restoring it to memory.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotSync</literal></entry>+ <entry>Waiting for a replication slot control file to reach stable+ storage.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotWrite</literal></entry>+ <entry>Waiting for a write to a replication slot control file.</entry>+ </row>+ <row>+ <entry><literal>SLRUFlushSync</literal></entry>+ <entry>Waiting for SLRU data to reach stable storage during a checkpoint+ or database shutdown.</entry>+ </row>+ <row>+ <entry><literal>SLRURead</literal></entry>+ <entry>Waiting for a read of an SLRU page.</entry>+ </row>+ <row>+ <entry><literal>SLRUSync</literal></entry>+ <entry>Waiting for SLRU data to reach stable storage following a page+ write.</entry>+ </row>+ <row>+ <entry><literal>SLRUWrite</literal></entry>+ <entry>Waiting for a write of an SLRU page.</entry>+ </row>+ <row>+ <entry><literal>SnapbuildRead</literal></entry>+ <entry>Waiting for a read of a serialized historical catalog+ snapshot.</entry>+ </row>+ <row>+ <entry><literal>SnapbuildSync</literal></entry>+ <entry>Waiting for a serialized historical catalog snapshot to reach+ stable storage.</entry>+ </row>+ <row>+ <entry><literal>SnapbuildWrite</literal></entry>+ <entry>Waiting for a write of a serialized historical catalog+ snapshot.</entry>+ </row>+ <row>+ <entry><literal>TimelineHistoryFileSync</literal></entry>+ <entry>Waiting for a timeline history file received via streaming+ replication to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>TimelineHistoryFileWrite</literal></entry>+ <entry>Waiting for a write of a timeline history file received via+ streaming replication.</entry>+ </row>+ <row>+ <entry><literal>TimelineHistoryRead</literal></entry>+ <entry>Waiting for a read of a timeline history file.</entry>+ </row>+ <row>+ <entry><literal>TimelineHistorySync</literal></entry>+ <entry>Waiting for a newly created timeline history file to reach stable+ storage.</entry>+ </row>+ <row>+ <entry><literal>TimelineHistoryWrite</literal></entry>+ <entry>Waiting for a write of a newly created timeline history+ file.</entry>+ </row>+ <row>+ <entry><literal>TwophaseFileRead</literal></entry>+ <entry>Waiting for a read of a two phase state file.</entry>+ </row>+ <row>+ <entry><literal>TwophaseFileSync</literal></entry>+ <entry>Waiting for a two phase state file to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>TwophaseFileWrite</literal></entry>+ <entry>Waiting for a write of a two phase state file.</entry>+ </row>+ <row>+ <entry><literal>WALBootstrapSync</literal></entry>+ <entry>Waiting for WAL to reach stable storage during+ bootstrapping.</entry>+ </row>+ <row>+ <entry><literal>WALBootstrapWrite</literal></entry>+ <entry>Waiting for a write of a WAL page during bootstrapping.</entry>+ </row>+ <row>+ <entry><literal>WALCopyRead</literal></entry>+ <entry>Waiting for a read when creating a new WAL segment by copying an+ existing one.</entry>+ </row>+ <row>+ <entry><literal>WALCopySync</literal></entry>+ <entry>Waiting for a new WAL segment created by copying an existing one to+ reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>WALCopyWrite</literal></entry>+ <entry>Waiting for a write when creating a new WAL segment by copying an+ existing one.</entry>+ </row>+ <row>+ <entry><literal>WALInitSync</literal></entry>+ <entry>Waiting for a newly initialized WAL file to reach stable+ storage.</entry>+ </row>+ <row>+ <entry><literal>WALInitWrite</literal></entry>+ <entry>Waiting for a write while initializing a new WAL file.</entry>+ </row>+ <row>+ <entry><literal>WALRead</literal></entry>+ <entry>Waiting for a read from a WAL file.</entry>+ </row>+ <row>+ <entry><literal>WALSenderTimelineHistoryRead</literal></entry>+ <entry>Waiting for a read from a timeline history file during walsender+ timeline command.</entry>+ </row>+ <row>+ <entry><literal>WALSync</literal></entry>+ <entry>Waiting for a WAL file to reach stable storage.</entry>+ </row>+ <row>+ <entry><literal>WALSyncMethodAssign</literal></entry>+ <entry>Waiting for data to reach stable storage while assigning WAL sync+ method.</entry>+ </row>+ <row>+ <entry><literal>WALWrite</literal></entry>+ <entry>Waiting for a write to a WAL file.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-ipc-table">+ <title>Wait Events of Type <literal>IPC</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>IPC</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>BackupWaitWalArchive</literal></entry>+ <entry>Waiting for WAL files required for the backup to be successfully+ archived.</entry>+ </row>+ <row>+ <entry><literal>BgWorkerShutdown</literal></entry>+ <entry>Waiting for background worker to shut down.</entry>+ </row>+ <row>+ <entry><literal>BgWorkerStartup</literal></entry>+ <entry>Waiting for background worker to start up.</entry>+ </row>+ <row>+ <entry><literal>BtreePage</literal></entry>+ <entry>Waiting for the page number needed to continue a parallel B-tree+ scan to become available.</entry>+ </row>+ <row>+ <entry><literal>CheckpointDone</literal></entry>+ <entry>Waiting for a checkpoint to complete.</entry>+ </row>+ <row>+ <entry><literal>CheckpointStart</literal></entry>+ <entry>Waiting for a checkpoint to start.</entry>+ </row>+ <row>+ <entry><literal>ClogGroupUpdate</literal></entry>+ <entry>Waiting for group leader to update transaction status at+ transaction end.</entry>+ </row>+ <row>+ <entry><literal>ExecuteGather</literal></entry>+ <entry>Waiting for activity from child process while+ executing <literal>Gather</literal> node.</entry>+ </row>+ <row>+ <entry><literal>Hash/Batch/Allocating</literal></entry>+ <entry>Waiting for an elected Parallel Hash participant to allocate a hash+ table.</entry>+ </row>+ <row>+ <entry><literal>Hash/Batch/Electing</literal></entry>+ <entry>Electing a Parallel Hash participant to allocate a hash table.</entry>+ </row>+ <row>+ <entry><literal>Hash/Batch/Loading</literal></entry>+ <entry>Waiting for other Parallel Hash participants to finish loading a+ hash table.</entry>+ </row>+ <row>+ <entry><literal>Hash/Build/Allocating</literal></entry>+ <entry>Waiting for an elected Parallel Hash participant to allocate the+ initial hash table.</entry>+ </row>+ <row>+ <entry><literal>Hash/Build/Electing</literal></entry>+ <entry>Electing a Parallel Hash participant to allocate the initial hash table.</entry>+ </row>+ <row>+ <entry><literal>Hash/Build/HashingInner</literal></entry>+ <entry>Waiting for other Parallel Hash participants to finish hashing the+ inner relation.</entry>+ </row>+ <row>+ <entry><literal>Hash/Build/HashingOuter</literal></entry>+ <entry>Waiting for other Parallel Hash participants to finish partitioning+ the outer relation.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBatches/Allocating</literal></entry>+ <entry>Waiting for an elected Parallel Hash participant to allocate more+ batches.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBatches/Deciding</literal></entry>+ <entry>Electing a Parallel Hash participant to decide on future batch growth.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBatches/Electing</literal></entry>+ <entry>Electing a Parallel Hash participant to allocate more batches.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBatches/Finishing</literal></entry>+ <entry>Waiting for an elected Parallel Hash participant to decide on+ future batch growth.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBatches/Repartitioning</literal></entry>+ <entry>Waiting for other Parallel Hash participants to finishing+ repartitioning.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBuckets/Allocating</literal></entry>+ <entry>Waiting for an elected Parallel Hash participant to finish+ allocating more buckets.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBuckets/Electing</literal></entry>+ <entry>Electing a Parallel Hash participant to allocate more buckets.</entry>+ </row>+ <row>+ <entry><literal>Hash/GrowBuckets/Reinserting</literal></entry>+ <entry>Waiting for other Parallel Hash participants to finish inserting+ tuples into new buckets.</entry>+ </row>+ <row>+ <entry><literal>LogicalSyncData</literal></entry>+ <entry>Waiting for logical replication remote server to send data for+ initial table synchronization.</entry>+ </row>+ <row>+ <entry><literal>LogicalSyncStateChange</literal></entry>+ <entry>Waiting for logical replication remote server to change state.</entry>+ </row>+ <row>+ <entry><literal>MessageQueueInternal</literal></entry>+ <entry>Waiting for other process to be attached in shared message queue.</entry>+ </row>+ <row>+ <entry><literal>MessageQueuePutMessage</literal></entry>+ <entry>Waiting to write a protocol message to a shared message queue.</entry>+ </row>+ <row>+ <entry><literal>MessageQueueReceive</literal></entry>+ <entry>Waiting to receive bytes from a shared message queue.</entry>+ </row>+ <row>+ <entry><literal>MessageQueueSend</literal></entry>+ <entry>Waiting to send bytes to a shared message queue.</entry>+ </row>+ <row>+ <entry><literal>ParallelBitmapScan</literal></entry>+ <entry>Waiting for parallel bitmap scan to become initialized.</entry>+ </row>+ <row>+ <entry><literal>ParallelCreateIndexScan</literal></entry>+ <entry>Waiting for parallel <command>CREATE INDEX</command> workers to+ finish heap scan.</entry>+ </row>+ <row>+ <entry><literal>ParallelFinish</literal></entry>+ <entry>Waiting for parallel workers to finish computing.</entry>+ </row>+ <row>+ <entry><literal>ProcArrayGroupUpdate</literal></entry>+ <entry>Waiting for group leader to clear transaction id at transaction end.</entry>+ </row>+ <row>+ <entry><literal>Promote</literal></entry>+ <entry>Waiting for standby promotion.</entry>+ </row>+ <row>+ <entry><literal>RecoveryConflictSnapshot</literal></entry>+ <entry>Waiting for recovery conflict resolution on a vacuum cleanup.</entry>+ </row>+ <row>+ <entry><literal>RecoveryConflictTablespace</literal></entry>+ <entry>Waiting for recovery conflict resolution on dropping tablespace.</entry>+ </row>+ <row>+ <entry><literal>RecoveryPause</literal></entry>+ <entry>Waiting for recovery to be resumed.</entry>+ </row>+ <row>+ <entry><literal>ReplicationOriginDrop</literal></entry>+ <entry>Waiting for a replication origin to become inactive to be dropped.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotDrop</literal></entry>+ <entry>Waiting for a replication slot to become inactive to be dropped.</entry>+ </row>+ <row>+ <entry><literal>SafeSnapshot</literal></entry>+ <entry>Waiting for a snapshot for a <literal>READ ONLY DEFERRABLE</literal>+ transaction.</entry>+ </row>+ <row>+ <entry><literal>SyncRep</literal></entry>+ <entry>Waiting for confirmation from remote server during synchronous+ replication.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-lock-table">+ <title>Wait Events of Type <literal>Lock</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>Lock</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>- <note>- <para>- The <structfield>wait_event</structfield> and <structfield>state</structfield> columns are- independent. If a backend is in the <literal>active</literal> state,- it may or may not be <literal>waiting</literal> on some event. If the state- is <literal>active</literal> and <structfield>wait_event</structfield> is non-null, it- means that a query is being executed, but is being blocked somewhere- in the system.- </para>- </note>+ <tbody>+ <row>+ <entry><literal>advisory</literal></entry>+ <entry>Waiting to acquire an advisory user lock.</entry>+ </row>+ <row>+ <entry><literal>extend</literal></entry>+ <entry>Waiting to extend a relation.</entry>+ </row>+ <row>+ <entry><literal>object</literal></entry>+ <entry>Waiting to acquire a lock on a non-relation database object.</entry>+ </row>+ <row>+ <entry><literal>page</literal></entry>+ <entry>Waiting to acquire a lock on page of a relation.</entry>+ </row>+ <row>+ <entry><literal>relation</literal></entry>+ <entry>Waiting to acquire a lock on a relation.</entry>+ </row>+ <row>+ <entry><literal>speculative token</literal></entry>+ <entry>Waiting to acquire a speculative insertion lock.</entry>+ </row>+ <row>+ <entry><literal>transactionid</literal></entry>+ <entry>Waiting for a transaction to finish.</entry>+ </row>+ <row>+ <entry><literal>tuple</literal></entry>+ <entry>Waiting to acquire a lock on a tuple.</entry>+ </row>+ <row>+ <entry><literal>userlock</literal></entry>+ <entry>Waiting to acquire a user lock.</entry>+ </row>+ <row>+ <entry><literal>virtualxid</literal></entry>+ <entry>Waiting to acquire a virtual xid lock.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>- <table id="wait-event-table">- <title><structname>wait_event</structname> Description</title>-- <tgroup cols="3">- <thead>- <row>- <entry>Wait Event Type</entry>- <entry>Wait Event Name</entry>- <entry>Description</entry>- </row>- </thead>-- <tbody>- <row>- <entry morerows="64"><literal>LWLock</literal></entry>- <entry><literal>ShmemIndexLock</literal></entry>- <entry>Waiting to find or allocate space in shared memory.</entry>- </row>- <row>- <entry><literal>OidGenLock</literal></entry>- <entry>Waiting to allocate or assign an OID.</entry>- </row>- <row>- <entry><literal>XidGenLock</literal></entry>- <entry>Waiting to allocate or assign a transaction id.</entry>- </row>- <row>- <entry><literal>ProcArrayLock</literal></entry>- <entry>Waiting to get a snapshot or clearing a transaction id at- transaction end.</entry>- </row>- <row>- <entry><literal>SInvalReadLock</literal></entry>- <entry>Waiting to retrieve or remove messages from shared invalidation- queue.</entry>- </row>- <row>- <entry><literal>SInvalWriteLock</literal></entry>- <entry>Waiting to add a message in shared invalidation queue.</entry>- </row>- <row>- <entry><literal>WALBufMappingLock</literal></entry>- <entry>Waiting to replace a page in WAL buffers.</entry>- </row>- <row>- <entry><literal>WALWriteLock</literal></entry>- <entry>Waiting for WAL buffers to be written to disk.</entry>- </row>- <row>- <entry><literal>ControlFileLock</literal></entry>- <entry>Waiting to read or update the control file or creation of a- new WAL file.</entry>- </row>- <row>- <entry><literal>CheckpointLock</literal></entry>- <entry>Waiting to perform checkpoint.</entry>- </row>- <row>- <entry><literal>CLogControlLock</literal></entry>- <entry>Waiting to read or update transaction status.</entry>- </row>- <row>- <entry><literal>SubtransControlLock</literal></entry>- <entry>Waiting to read or update sub-transaction information.</entry>- </row>- <row>- <entry><literal>MultiXactGenLock</literal></entry>- <entry>Waiting to read or update shared multixact state.</entry>- </row>- <row>- <entry><literal>MultiXactOffsetControlLock</literal></entry>- <entry>Waiting to read or update multixact offset mappings.</entry>- </row>- <row>- <entry><literal>MultiXactMemberControlLock</literal></entry>- <entry>Waiting to read or update multixact member mappings.</entry>- </row>- <row>- <entry><literal>RelCacheInitLock</literal></entry>- <entry>Waiting to read or write relation cache initialization- file.</entry>- </row>- <row>- <entry><literal>CheckpointerCommLock</literal></entry>- <entry>Waiting to manage fsync requests.</entry>- </row>- <row>- <entry><literal>TwoPhaseStateLock</literal></entry>- <entry>Waiting to read or update the state of prepared transactions.</entry>- </row>- <row>- <entry><literal>TablespaceCreateLock</literal></entry>- <entry>Waiting to create or drop the tablespace.</entry>- </row>- <row>- <entry><literal>BtreeVacuumLock</literal></entry>- <entry>Waiting to read or update vacuum-related information for a- B-tree index.</entry>- </row>- <row>- <entry><literal>AddinShmemInitLock</literal></entry>- <entry>Waiting to manage space allocation in shared memory.</entry>- </row>- <row>- <entry><literal>AutovacuumLock</literal></entry>- <entry>Autovacuum worker or launcher waiting to update or- read the current state of autovacuum workers.</entry>- </row>- <row>- <entry><literal>AutovacuumScheduleLock</literal></entry>- <entry>Waiting to ensure that the table it has selected for a vacuum- still needs vacuuming.- </entry>- </row>- <row>- <entry><literal>SyncScanLock</literal></entry>- <entry>Waiting to get the start location of a scan on a table for- synchronized scans.</entry>- </row>- <row>- <entry><literal>RelationMappingLock</literal></entry>- <entry>Waiting to update the relation map file used to store catalog- to filenode mapping.- </entry>- </row>- <row>- <entry><literal>AsyncCtlLock</literal></entry>- <entry>Waiting to read or update shared notification state.</entry>- </row>- <row>- <entry><literal>AsyncQueueLock</literal></entry>- <entry>Waiting to read or update notification messages.</entry>- </row>- <row>- <entry><literal>SerializableXactHashLock</literal></entry>- <entry>Waiting to retrieve or store information about serializable- transactions.</entry>- </row>- <row>- <entry><literal>SerializableFinishedListLock</literal></entry>- <entry>Waiting to access the list of finished serializable- transactions.</entry>- </row>- <row>- <entry><literal>SerializablePredicateLockListLock</literal></entry>- <entry>Waiting to perform an operation on a list of locks held by- serializable transactions.</entry>- </row>- <row>- <entry><literal>OldSerXidLock</literal></entry>- <entry>Waiting to read or record conflicting serializable- transactions.</entry>- </row>- <row>- <entry><literal>SyncRepLock</literal></entry>- <entry>Waiting to read or update information about synchronous- replicas.</entry>- </row>- <row>- <entry><literal>BackgroundWorkerLock</literal></entry>- <entry>Waiting to read or update background worker state.</entry>- </row>- <row>- <entry><literal>DynamicSharedMemoryControlLock</literal></entry>- <entry>Waiting to read or update dynamic shared memory state.</entry>- </row>- <row>- <entry><literal>AutoFileLock</literal></entry>- <entry>Waiting to update the <filename>postgresql.auto.conf</filename> file.</entry>- </row>- <row>- <entry><literal>ReplicationSlotAllocationLock</literal></entry>- <entry>Waiting to allocate or free a replication slot.</entry>- </row>- <row>- <entry><literal>ReplicationSlotControlLock</literal></entry>- <entry>Waiting to read or update replication slot state.</entry>- </row>- <row>- <entry><literal>CommitTsControlLock</literal></entry>- <entry>Waiting to read or update transaction commit timestamps.</entry>- </row>- <row>- <entry><literal>CommitTsLock</literal></entry>- <entry>Waiting to read or update the last value set for the- transaction timestamp.</entry>- </row>- <row>- <entry><literal>ReplicationOriginLock</literal></entry>- <entry>Waiting to setup, drop or use replication origin.</entry>- </row>- <row>- <entry><literal>MultiXactTruncationLock</literal></entry>- <entry>Waiting to read or truncate multixact information.</entry>- </row>- <row>- <entry><literal>OldSnapshotTimeMapLock</literal></entry>- <entry>Waiting to read or update old snapshot control information.</entry>- </row>- <row>- <entry><literal>LogicalRepWorkerLock</literal></entry>- <entry>Waiting for action on logical replication worker to finish.</entry>- </row>- <row>- <entry><literal>CLogTruncationLock</literal></entry>- <entry>Waiting to execute <function>pg_xact_status</function> or update- the oldest transaction id available to it.</entry>- </row>- <row>- <entry><literal>clog</literal></entry>- <entry>Waiting for I/O on a clog (transaction status) buffer.</entry>- </row>- <row>- <entry><literal>commit_timestamp</literal></entry>- <entry>Waiting for I/O on commit timestamp buffer.</entry>- </row>- <row>- <entry><literal>subtrans</literal></entry>- <entry>Waiting for I/O a subtransaction buffer.</entry>- </row>- <row>- <entry><literal>multixact_offset</literal></entry>- <entry>Waiting for I/O on a multixact offset buffer.</entry>- </row>- <row>- <entry><literal>multixact_member</literal></entry>- <entry>Waiting for I/O on a multixact_member buffer.</entry>- </row>- <row>- <entry><literal>async</literal></entry>- <entry>Waiting for I/O on an async (notify) buffer.</entry>- </row>- <row>- <entry><literal>oldserxid</literal></entry>- <entry>Waiting for I/O on an oldserxid buffer.</entry>- </row>- <row>- <entry><literal>wal_insert</literal></entry>- <entry>Waiting to insert WAL into a memory buffer.</entry>- </row>- <row>- <entry><literal>buffer_content</literal></entry>- <entry>Waiting to read or write a data page in memory.</entry>- </row>- <row>- <entry><literal>buffer_io</literal></entry>- <entry>Waiting for I/O on a data page.</entry>- </row>- <row>- <entry><literal>replication_origin</literal></entry>- <entry>Waiting to read or update the replication progress.</entry>- </row>- <row>- <entry><literal>replication_slot_io</literal></entry>- <entry>Waiting for I/O on a replication slot.</entry>- </row>- <row>- <entry><literal>proc</literal></entry>- <entry>Waiting to read or update the fast-path lock information.</entry>- </row>- <row>- <entry><literal>buffer_mapping</literal></entry>- <entry>Waiting to associate a data block with a buffer in the buffer- pool.</entry>- </row>- <row>- <entry><literal>lock_manager</literal></entry>- <entry>Waiting to add or examine locks for backends, or waiting to- join or exit a locking group (used by parallel query).</entry>- </row>- <row>- <entry><literal>predicate_lock_manager</literal></entry>- <entry>Waiting to add or examine predicate lock information.</entry>- </row>- <row>- <entry><literal>serializable_xact</literal></entry>- <entry>Waiting to perform an operation on a serializable transaction- in a parallel query.</entry>- </row>- <row>- <entry><literal>parallel_query_dsa</literal></entry>- <entry>Waiting for parallel query dynamic shared memory allocation lock.</entry>- </row>- <row>- <entry><literal>tbm</literal></entry>- <entry>Waiting for TBM shared iterator lock.</entry>- </row>- <row>- <entry><literal>parallel_append</literal></entry>- <entry>Waiting to choose the next subplan during Parallel Append plan- execution.</entry>- </row>- <row>- <entry><literal>parallel_hash_join</literal></entry>- <entry>Waiting to allocate or exchange a chunk of memory or update- counters during Parallel Hash plan execution.</entry>- </row>- <row>- <entry morerows="9"><literal>Lock</literal></entry>- <entry><literal>relation</literal></entry>- <entry>Waiting to acquire a lock on a relation.</entry>- </row>- <row>- <entry><literal>extend</literal></entry>- <entry>Waiting to extend a relation.</entry>- </row>- <row>- <entry><literal>page</literal></entry>- <entry>Waiting to acquire a lock on page of a relation.</entry>- </row>- <row>- <entry><literal>tuple</literal></entry>- <entry>Waiting to acquire a lock on a tuple.</entry>- </row>- <row>- <entry><literal>transactionid</literal></entry>- <entry>Waiting for a transaction to finish.</entry>- </row>- <row>- <entry><literal>virtualxid</literal></entry>- <entry>Waiting to acquire a virtual xid lock.</entry>- </row>- <row>- <entry><literal>speculative token</literal></entry>- <entry>Waiting to acquire a speculative insertion lock.</entry>- </row>- <row>- <entry><literal>object</literal></entry>- <entry>Waiting to acquire a lock on a non-relation database object.</entry>- </row>- <row>- <entry><literal>userlock</literal></entry>- <entry>Waiting to acquire a user lock.</entry>- </row>- <row>- <entry><literal>advisory</literal></entry>- <entry>Waiting to acquire an advisory user lock.</entry>- </row>- <row>- <entry><literal>BufferPin</literal></entry>- <entry><literal>BufferPin</literal></entry>- <entry>Waiting to acquire a pin on a buffer.</entry>- </row>- <row>- <entry morerows="12"><literal>Activity</literal></entry>- <entry><literal>ArchiverMain</literal></entry>- <entry>Waiting in main loop of the archiver process.</entry>- </row>- <row>- <entry><literal>AutoVacuumMain</literal></entry>- <entry>Waiting in main loop of autovacuum launcher process.</entry>- </row>- <row>- <entry><literal>BgWriterHibernate</literal></entry>- <entry>Waiting in background writer process, hibernating.</entry>- </row>- <row>- <entry><literal>BgWriterMain</literal></entry>- <entry>Waiting in main loop of background writer process background worker.</entry>- </row>- <row>- <entry><literal>CheckpointerMain</literal></entry>- <entry>Waiting in main loop of checkpointer process.</entry>- </row>- <row>- <entry><literal>LogicalApplyMain</literal></entry>- <entry>Waiting in main loop of logical apply process.</entry>- </row>- <row>- <entry><literal>LogicalLauncherMain</literal></entry>- <entry>Waiting in main loop of logical launcher process.</entry>- </row>- <row>- <entry><literal>PgStatMain</literal></entry>- <entry>Waiting in main loop of the statistics collector process.</entry>- </row>- <row>- <entry><literal>RecoveryWalStream</literal></entry>- <entry>Waiting for WAL from a stream at recovery.</entry>- </row>- <row>- <entry><literal>SysLoggerMain</literal></entry>- <entry>Waiting in main loop of syslogger process.</entry>- </row>- <row>- <entry><literal>WalReceiverMain</literal></entry>- <entry>Waiting in main loop of WAL receiver process.</entry>- </row>- <row>- <entry><literal>WalSenderMain</literal></entry>- <entry>Waiting in main loop of WAL sender process.</entry>- </row>- <row>- <entry><literal>WalWriterMain</literal></entry>- <entry>Waiting in main loop of WAL writer process.</entry>- </row>- <row>- <entry morerows="8"><literal>Client</literal></entry>- <entry><literal>ClientRead</literal></entry>- <entry>Waiting to read data from the client.</entry>- </row>- <row>- <entry><literal>ClientWrite</literal></entry>- <entry>Waiting to write data to the client.</entry>- </row>- <row>- <entry><literal>GSSOpenServer</literal></entry>- <entry>Waiting to read data from the client while establishing the GSSAPI session.</entry>- </row>- <row>- <entry><literal>LibPQWalReceiverConnect</literal></entry>- <entry>Waiting in WAL receiver to establish connection to remote server.</entry>- </row>- <row>- <entry><literal>LibPQWalReceiverReceive</literal></entry>- <entry>Waiting in WAL receiver to receive data from remote server.</entry>- </row>- <row>- <entry><literal>SSLOpenServer</literal></entry>- <entry>Waiting for SSL while attempting connection.</entry>- </row>- <row>- <entry><literal>WalReceiverWaitStart</literal></entry>- <entry>Waiting for startup process to send initial data for streaming replication.</entry>- </row>- <row>- <entry><literal>WalSenderWaitForWAL</literal></entry>- <entry>Waiting for WAL to be flushed in WAL sender process.</entry>- </row>- <row>- <entry><literal>WalSenderWriteData</literal></entry>- <entry>Waiting for any activity when processing replies from WAL receiver in WAL sender process.</entry>- </row>- <row>- <entry><literal>Extension</literal></entry>- <entry><literal>Extension</literal></entry>- <entry>Waiting in an extension.</entry>- </row>- <row>- <entry morerows="40"><literal>IPC</literal></entry>- <entry><literal>BackupWaitWalArchive</literal></entry>- <entry>Waiting for WAL files required for the backup to be successfully archived.</entry>- </row>- <row>- <entry><literal>BgWorkerShutdown</literal></entry>- <entry>Waiting for background worker to shut down.</entry>- </row>- <row>- <entry><literal>BgWorkerStartup</literal></entry>- <entry>Waiting for background worker to start up.</entry>- </row>- <row>- <entry><literal>BtreePage</literal></entry>- <entry>Waiting for the page number needed to continue a parallel B-tree scan to become available.</entry>- </row>- <row>- <entry><literal>CheckpointDone</literal></entry>- <entry>Waiting for a checkpoint to complete.</entry>- </row>- <row>- <entry><literal>CheckpointStart</literal></entry>- <entry>Waiting for a checkpoint to start.</entry>- </row>- <row>- <entry><literal>ClogGroupUpdate</literal></entry>- <entry>Waiting for group leader to update transaction status at transaction end.</entry>- </row>- <row>- <entry><literal>ExecuteGather</literal></entry>- <entry>Waiting for activity from child process when executing <literal>Gather</literal> node.</entry>- </row>- <row>- <entry><literal>Hash/Batch/Allocating</literal></entry>- <entry>Waiting for an elected Parallel Hash participant to allocate a hash table.</entry>- </row>- <row>- <entry><literal>Hash/Batch/Electing</literal></entry>- <entry>Electing a Parallel Hash participant to allocate a hash table.</entry>- </row>- <row>- <entry><literal>Hash/Batch/Loading</literal></entry>- <entry>Waiting for other Parallel Hash participants to finish loading a hash table.</entry>- </row>- <row>- <entry><literal>Hash/Build/Allocating</literal></entry>- <entry>Waiting for an elected Parallel Hash participant to allocate the initial hash table.</entry>- </row>- <row>- <entry><literal>Hash/Build/Electing</literal></entry>- <entry>Electing a Parallel Hash participant to allocate the initial hash table.</entry>- </row>- <row>- <entry><literal>Hash/Build/HashingInner</literal></entry>- <entry>Waiting for other Parallel Hash participants to finish hashing the inner relation.</entry>- </row>- <row>- <entry><literal>Hash/Build/HashingOuter</literal></entry>- <entry>Waiting for other Parallel Hash participants to finish partitioning the outer relation.</entry>- </row>- <row>- <entry><literal>Hash/GrowBatches/Allocating</literal></entry>- <entry>Waiting for an elected Parallel Hash participant to allocate more batches.</entry>- </row>- <row>- <entry><literal>Hash/GrowBatches/Deciding</literal></entry>- <entry>Electing a Parallel Hash participant to decide on future batch growth.</entry>- </row>- <row>- <entry><literal>Hash/GrowBatches/Electing</literal></entry>- <entry>Electing a Parallel Hash participant to allocate more batches.</entry>- </row>- <row>- <entry><literal>Hash/GrowBatches/Finishing</literal></entry>- <entry>Waiting for an elected Parallel Hash participant to decide on future batch growth.</entry>- </row>- <row>- <entry><literal>Hash/GrowBatches/Repartitioning</literal></entry>- <entry>Waiting for other Parallel Hash participants to finishing repartitioning.</entry>- </row>- <row>- <entry><literal>Hash/GrowBuckets/Allocating</literal></entry>- <entry>Waiting for an elected Parallel Hash participant to finish allocating more buckets.</entry>- </row>- <row>- <entry><literal>Hash/GrowBuckets/Electing</literal></entry>- <entry>Electing a Parallel Hash participant to allocate more buckets.</entry>- </row>- <row>- <entry><literal>Hash/GrowBuckets/Reinserting</literal></entry>- <entry>Waiting for other Parallel Hash participants to finish inserting tuples into new buckets.</entry>- </row>- <row>- <entry><literal>LogicalSyncData</literal></entry>- <entry>Waiting for logical replication remote server to send data for initial table synchronization.</entry>- </row>- <row>- <entry><literal>LogicalSyncStateChange</literal></entry>- <entry>Waiting for logical replication remote server to change state.</entry>- </row>- <row>- <entry><literal>MessageQueueInternal</literal></entry>- <entry>Waiting for other process to be attached in shared message queue.</entry>- </row>- <row>- <entry><literal>MessageQueuePutMessage</literal></entry>- <entry>Waiting to write a protocol message to a shared message queue.</entry>- </row>- <row>- <entry><literal>MessageQueueReceive</literal></entry>- <entry>Waiting to receive bytes from a shared message queue.</entry>- </row>- <row>- <entry><literal>MessageQueueSend</literal></entry>- <entry>Waiting to send bytes to a shared message queue.</entry>- </row>- <row>- <entry><literal>ParallelBitmapScan</literal></entry>- <entry>Waiting for parallel bitmap scan to become initialized.</entry>- </row>- <row>- <entry><literal>ParallelCreateIndexScan</literal></entry>- <entry>Waiting for parallel <command>CREATE INDEX</command> workers to finish heap scan.</entry>- </row>- <row>- <entry><literal>ParallelFinish</literal></entry>- <entry>Waiting for parallel workers to finish computing.</entry>- </row>- <row>- <entry><literal>ProcArrayGroupUpdate</literal></entry>- <entry>Waiting for group leader to clear transaction id at transaction end.</entry>- </row>- <row>- <entry><literal>Promote</literal></entry>- <entry>Waiting for standby promotion.</entry>- </row>- <row>- <entry><literal>RecoveryConflictSnapshot</literal></entry>- <entry>Waiting for recovery conflict resolution on a vacuum cleanup.</entry>- </row>- <row>- <entry><literal>RecoveryConflictTablespace</literal></entry>- <entry>Waiting for recovery conflict resolution on dropping tablespace.</entry>- </row>- <row>- <entry><literal>RecoveryPause</literal></entry>- <entry>Waiting for recovery to be resumed.</entry>- </row>- <row>- <entry><literal>ReplicationOriginDrop</literal></entry>- <entry>Waiting for a replication origin to become inactive to be dropped.</entry>- </row>- <row>- <entry><literal>ReplicationSlotDrop</literal></entry>- <entry>Waiting for a replication slot to become inactive to be dropped.</entry>- </row>- <row>- <entry><literal>SafeSnapshot</literal></entry>- <entry>Waiting for a snapshot for a <literal>READ ONLY DEFERRABLE</literal> transaction.</entry>- </row>- <row>- <entry><literal>SyncRep</literal></entry>- <entry>Waiting for confirmation from remote server during synchronous replication.</entry>- </row>- <row>- <entry morerows="4"><literal>Timeout</literal></entry>- <entry><literal>BaseBackupThrottle</literal></entry>- <entry>Waiting during base backup when throttling activity.</entry>- </row>- <row>- <entry><literal>PgSleep</literal></entry>- <entry>Waiting in process that called <function>pg_sleep</function>.</entry>- </row>- <row>- <entry><literal>RecoveryApplyDelay</literal></entry>- <entry>Waiting to apply WAL at recovery because it is delayed.</entry>- </row>- <row>- <entry><literal>RecoveryRetrieveRetryInterval</literal></entry>- <entry>- Waiting when WAL data is not available from any kind of sources- (<filename>pg_wal</filename>, archive or stream) before trying- again to retrieve WAL data, at recovery.- </entry>- </row>- <row>- <entry><literal>VacuumDelay</literal></entry>- <entry>Waiting in a cost-based vacuum delay point.</entry>- </row>- <row>- <entry morerows="68"><literal>IO</literal></entry>- <entry><literal>BufFileRead</literal></entry>- <entry>Waiting for a read from a buffered file.</entry>- </row>- <row>- <entry><literal>BufFileWrite</literal></entry>- <entry>Waiting for a write to a buffered file.</entry>- </row>- <row>- <entry><literal>ControlFileRead</literal></entry>- <entry>Waiting for a read from the control file.</entry>- </row>- <row>- <entry><literal>ControlFileSync</literal></entry>- <entry>Waiting for the control file to reach stable storage.</entry>- </row>- <row>- <entry><literal>ControlFileSyncUpdate</literal></entry>- <entry>Waiting for an update to the control file to reach stable storage.</entry>- </row>- <row>- <entry><literal>ControlFileWrite</literal></entry>- <entry>Waiting for a write to the control file.</entry>- </row>- <row>- <entry><literal>ControlFileWriteUpdate</literal></entry>- <entry>Waiting for a write to update the control file.</entry>- </row>- <row>- <entry><literal>CopyFileRead</literal></entry>- <entry>Waiting for a read during a file copy operation.</entry>- </row>- <row>- <entry><literal>CopyFileWrite</literal></entry>- <entry>Waiting for a write during a file copy operation.</entry>- </row>- <row>- <entry><literal>DataFileExtend</literal></entry>- <entry>Waiting for a relation data file to be extended.</entry>- </row>- <row>- <entry><literal>DataFileFlush</literal></entry>- <entry>Waiting for a relation data file to reach stable storage.</entry>- </row>- <row>- <entry><literal>DataFileImmediateSync</literal></entry>- <entry>Waiting for an immediate synchronization of a relation data file to stable storage.</entry>- </row>- <row>- <entry><literal>DataFilePrefetch</literal></entry>- <entry>Waiting for an asynchronous prefetch from a relation data file.</entry>- </row>- <row>- <entry><literal>DataFileRead</literal></entry>- <entry>Waiting for a read from a relation data file.</entry>- </row>- <row>- <entry><literal>DataFileSync</literal></entry>- <entry>Waiting for changes to a relation data file to reach stable storage.</entry>- </row>- <row>- <entry><literal>DataFileTruncate</literal></entry>- <entry>Waiting for a relation data file to be truncated.</entry>- </row>- <row>- <entry><literal>DataFileWrite</literal></entry>- <entry>Waiting for a write to a relation data file.</entry>- </row>- <row>- <entry><literal>DSMFillZeroWrite</literal></entry>- <entry>Waiting to write zero bytes to a dynamic shared memory backing file.</entry>- </row>- <row>- <entry><literal>LockFileAddToDataDirRead</literal></entry>- <entry>Waiting for a read while adding a line to the data directory lock file.</entry>- </row>- <row>- <entry><literal>LockFileAddToDataDirSync</literal></entry>- <entry>Waiting for data to reach stable storage while adding a line to the data directory lock file.</entry>- </row>- <row>- <entry><literal>LockFileAddToDataDirWrite</literal></entry>- <entry>Waiting for a write while adding a line to the data directory lock file.</entry>- </row>- <row>- <entry><literal>LockFileCreateRead</literal></entry>- <entry>Waiting to read while creating the data directory lock file.</entry>- </row>- <row>- <entry><literal>LockFileCreateSync</literal></entry>- <entry>Waiting for data to reach stable storage while creating the data directory lock file.</entry>- </row>- <row>- <entry><literal>LockFileCreateWrite</literal></entry>- <entry>Waiting for a write while creating the data directory lock file.</entry>- </row>- <row>- <entry><literal>LockFileReCheckDataDirRead</literal></entry>- <entry>Waiting for a read during recheck of the data directory lock file.</entry>- </row>- <row>- <entry><literal>LogicalRewriteCheckpointSync</literal></entry>- <entry>Waiting for logical rewrite mappings to reach stable storage during a checkpoint.</entry>- </row>- <row>- <entry><literal>LogicalRewriteMappingSync</literal></entry>- <entry>Waiting for mapping data to reach stable storage during a logical rewrite.</entry>- </row>- <row>- <entry><literal>LogicalRewriteMappingWrite</literal></entry>- <entry>Waiting for a write of mapping data during a logical rewrite.</entry>- </row>- <row>- <entry><literal>LogicalRewriteSync</literal></entry>- <entry>Waiting for logical rewrite mappings to reach stable storage.</entry>- </row>- <row>- <entry><literal>LogicalRewriteTruncate</literal></entry>- <entry>Waiting for truncate of mapping data during a logical rewrite.</entry>- </row>- <row>- <entry><literal>LogicalRewriteWrite</literal></entry>- <entry>Waiting for a write of logical rewrite mappings.</entry>- </row>- <row>- <entry><literal>ProcSignalBarrier</literal></entry>- <entry>Waiting for a barrier event to be processed by all backends.</entry>- </row>- <row>- <entry><literal>RelationMapRead</literal></entry>- <entry>Waiting for a read of the relation map file.</entry>- </row>- <row>- <entry><literal>RelationMapSync</literal></entry>- <entry>Waiting for the relation map file to reach stable storage.</entry>- </row>- <row>- <entry><literal>RelationMapWrite</literal></entry>- <entry>Waiting for a write to the relation map file.</entry>- </row>- <row>- <entry><literal>ReorderBufferRead</literal></entry>- <entry>Waiting for a read during reorder buffer management.</entry>- </row>- <row>- <entry><literal>ReorderBufferWrite</literal></entry>- <entry>Waiting for a write during reorder buffer management.</entry>- </row>- <row>- <entry><literal>ReorderLogicalMappingRead</literal></entry>- <entry>Waiting for a read of a logical mapping during reorder buffer management.</entry>- </row>- <row>- <entry><literal>ReplicationSlotRead</literal></entry>- <entry>Waiting for a read from a replication slot control file.</entry>- </row>- <row>- <entry><literal>ReplicationSlotRestoreSync</literal></entry>- <entry>Waiting for a replication slot control file to reach stable storage while restoring it to memory.</entry>- </row>- <row>- <entry><literal>ReplicationSlotSync</literal></entry>- <entry>Waiting for a replication slot control file to reach stable storage.</entry>- </row>- <row>- <entry><literal>ReplicationSlotWrite</literal></entry>- <entry>Waiting for a write to a replication slot control file.</entry>- </row>- <row>- <entry><literal>SLRUFlushSync</literal></entry>- <entry>Waiting for SLRU data to reach stable storage during a checkpoint or database shutdown.</entry>- </row>- <row>- <entry><literal>SLRURead</literal></entry>- <entry>Waiting for a read of an SLRU page.</entry>- </row>- <row>- <entry><literal>SLRUSync</literal></entry>- <entry>Waiting for SLRU data to reach stable storage following a page write.</entry>- </row>- <row>- <entry><literal>SLRUWrite</literal></entry>- <entry>Waiting for a write of an SLRU page.</entry>- </row>- <row>- <entry><literal>SnapbuildRead</literal></entry>- <entry>Waiting for a read of a serialized historical catalog snapshot.</entry>- </row>- <row>- <entry><literal>SnapbuildSync</literal></entry>- <entry>Waiting for a serialized historical catalog snapshot to reach stable storage.</entry>- </row>- <row>- <entry><literal>SnapbuildWrite</literal></entry>- <entry>Waiting for a write of a serialized historical catalog snapshot.</entry>- </row>- <row>- <entry><literal>TimelineHistoryFileSync</literal></entry>- <entry>Waiting for a timeline history file received via streaming replication to reach stable storage.</entry>- </row>- <row>- <entry><literal>TimelineHistoryFileWrite</literal></entry>- <entry>Waiting for a write of a timeline history file received via streaming replication.</entry>- </row>- <row>- <entry><literal>TimelineHistoryRead</literal></entry>- <entry>Waiting for a read of a timeline history file.</entry>- </row>- <row>- <entry><literal>TimelineHistorySync</literal></entry>- <entry>Waiting for a newly created timeline history file to reach stable storage.</entry>- </row>- <row>- <entry><literal>TimelineHistoryWrite</literal></entry>- <entry>Waiting for a write of a newly created timeline history file.</entry>- </row>- <row>- <entry><literal>TwophaseFileRead</literal></entry>- <entry>Waiting for a read of a two phase state file.</entry>- </row>- <row>- <entry><literal>TwophaseFileSync</literal></entry>- <entry>Waiting for a two phase state file to reach stable storage.</entry>- </row>- <row>- <entry><literal>TwophaseFileWrite</literal></entry>- <entry>Waiting for a write of a two phase state file.</entry>- </row>- <row>- <entry><literal>WALBootstrapSync</literal></entry>- <entry>Waiting for WAL to reach stable storage during bootstrapping.</entry>- </row>- <row>- <entry><literal>WALBootstrapWrite</literal></entry>- <entry>Waiting for a write of a WAL page during bootstrapping.</entry>- </row>- <row>- <entry><literal>WALCopyRead</literal></entry>- <entry>Waiting for a read when creating a new WAL segment by copying an existing one.</entry>- </row>- <row>- <entry><literal>WALCopySync</literal></entry>- <entry>Waiting a new WAL segment created by copying an existing one to reach stable storage.</entry>- </row>- <row>- <entry><literal>WALCopyWrite</literal></entry>- <entry>Waiting for a write when creating a new WAL segment by copying an existing one.</entry>- </row>- <row>- <entry><literal>WALInitSync</literal></entry>- <entry>Waiting for a newly initialized WAL file to reach stable storage.</entry>- </row>- <row>- <entry><literal>WALInitWrite</literal></entry>- <entry>Waiting for a write while initializing a new WAL file.</entry>- </row>- <row>- <entry><literal>WALRead</literal></entry>- <entry>Waiting for a read from a WAL file.</entry>- </row>- <row>- <entry><literal>WALSenderTimelineHistoryRead</literal></entry>- <entry>Waiting for a read from a timeline history file during walsender timeline command.</entry>- </row>- <row>- <entry><literal>WALSync</literal></entry>- <entry>Waiting for a WAL file to reach stable storage.</entry>- </row>- <row>- <entry><literal>WALSyncMethodAssign</literal></entry>- <entry>Waiting for data to reach stable storage while assigning WAL sync method.</entry>- </row>- <row>- <entry><literal>WALWrite</literal></entry>- <entry>Waiting for a write to a WAL file.</entry>- </row>- </tbody>- </tgroup>- </table>+ <table id="wait-event-lwlock-table">+ <title>Wait Events of Type <literal>LWLock</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>LWLock</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>AddinShmemInitLock</literal></entry>+ <entry>Waiting to manage space allocation in shared memory.</entry>+ </row>+ <row>+ <entry><literal>AsyncCtlLock</literal></entry>+ <entry>Waiting to read or update shared notification state.</entry>+ </row>+ <row>+ <entry><literal>AsyncQueueLock</literal></entry>+ <entry>Waiting to read or update notification messages.</entry>+ </row>+ <row>+ <entry><literal>AutoFileLock</literal></entry>+ <entry>Waiting to update the <filename>postgresql.auto.conf</filename> file.</entry>+ </row>+ <row>+ <entry><literal>AutovacuumLock</literal></entry>+ <entry>Autovacuum worker or launcher waiting to update or+ read the current state of autovacuum workers.</entry>+ </row>+ <row>+ <entry><literal>AutovacuumScheduleLock</literal></entry>+ <entry>Waiting to ensure that the table selected for a vacuum+ still needs vacuuming.</entry>+ </row>+ <row>+ <entry><literal>BackgroundWorkerLock</literal></entry>+ <entry>Waiting to read or update background worker state.</entry>+ </row>+ <row>+ <entry><literal>BtreeVacuumLock</literal></entry>+ <entry>Waiting to read or update vacuum-related information for a+ B-tree index.</entry>+ </row>+ <row>+ <entry><literal>CLogControlLock</literal></entry>+ <entry>Waiting to read or update transaction status.</entry>+ </row>+ <row>+ <entry><literal>CLogTruncationLock</literal></entry>+ <entry>Waiting to execute <function>pg_xact_status</function> or update+ the oldest transaction id available to it.</entry>+ </row>+ <row>+ <entry><literal>CheckpointLock</literal></entry>+ <entry>Waiting to perform checkpoint.</entry>+ </row>+ <row>+ <entry><literal>CheckpointerCommLock</literal></entry>+ <entry>Waiting to manage fsync requests.</entry>+ </row>+ <row>+ <entry><literal>CommitTsControlLock</literal></entry>+ <entry>Waiting to read or update transaction commit timestamps.</entry>+ </row>+ <row>+ <entry><literal>CommitTsLock</literal></entry>+ <entry>Waiting to read or update the last value set for the+ transaction timestamp.</entry>+ </row>+ <row>+ <entry><literal>ControlFileLock</literal></entry>+ <entry>Waiting to read or update the control file or creation of a+ new WAL file.</entry>+ </row>+ <row>+ <entry><literal>DynamicSharedMemoryControlLock</literal></entry>+ <entry>Waiting to read or update dynamic shared memory state.</entry>+ </row>+ <row>+ <entry><literal>LogicalRepWorkerLock</literal></entry>+ <entry>Waiting for action on logical replication worker to finish.</entry>+ </row>+ <row>+ <entry><literal>MultiXactGenLock</literal></entry>+ <entry>Waiting to read or update shared multixact state.</entry>+ </row>+ <row>+ <entry><literal>MultiXactMemberControlLock</literal></entry>+ <entry>Waiting to read or update multixact member mappings.</entry>+ </row>+ <row>+ <entry><literal>MultiXactOffsetControlLock</literal></entry>+ <entry>Waiting to read or update multixact offset mappings.</entry>+ </row>+ <row>+ <entry><literal>MultiXactTruncationLock</literal></entry>+ <entry>Waiting to read or truncate multixact information.</entry>+ </row>+ <row>+ <entry><literal>OidGenLock</literal></entry>+ <entry>Waiting to allocate or assign an OID.</entry>+ </row>+ <row>+ <entry><literal>OldSerXidLock</literal></entry>+ <entry>Waiting to read or record conflicting serializable+ transactions.</entry>+ </row>+ <row>+ <entry><literal>OldSnapshotTimeMapLock</literal></entry>+ <entry>Waiting to read or update old snapshot control information.</entry>+ </row>+ <row>+ <entry><literal>ProcArrayLock</literal></entry>+ <entry>Waiting to get a snapshot or clearing a transaction id at+ transaction end.</entry>+ </row>+ <row>+ <entry><literal>RelCacheInitLock</literal></entry>+ <entry>Waiting to read or write relation cache initialization file.</entry>+ </row>+ <row>+ <entry><literal>RelationMappingLock</literal></entry>+ <entry>Waiting to update the relation map file used to store catalog+ to filenode mapping.</entry>+ </row>+ <row>+ <entry><literal>ReplicationOriginLock</literal></entry>+ <entry>Waiting to setup, drop or use replication origin.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotAllocationLock</literal></entry>+ <entry>Waiting to allocate or free a replication slot.</entry>+ </row>+ <row>+ <entry><literal>ReplicationSlotControlLock</literal></entry>+ <entry>Waiting to read or update replication slot state.</entry>+ </row>+ <row>+ <entry><literal>SInvalReadLock</literal></entry>+ <entry>Waiting to retrieve or remove messages from shared invalidation+ queue.</entry>+ </row>+ <row>+ <entry><literal>SInvalWriteLock</literal></entry>+ <entry>Waiting to add a message in shared invalidation queue.</entry>+ </row>+ <row>+ <entry><literal>SerializableFinishedListLock</literal></entry>+ <entry>Waiting to access the list of finished serializable+ transactions.</entry>+ </row>+ <row>+ <entry><literal>SerializablePredicateLockListLock</literal></entry>+ <entry>Waiting to perform an operation on a list of locks held by+ serializable transactions.</entry>+ </row>+ <row>+ <entry><literal>SerializableXactHashLock</literal></entry>+ <entry>Waiting to retrieve or store information about serializable+ transactions.</entry>+ </row>+ <row>+ <entry><literal>ShmemIndexLock</literal></entry>+ <entry>Waiting to find or allocate space in shared memory.</entry>+ </row>+ <row>+ <entry><literal>SubtransControlLock</literal></entry>+ <entry>Waiting to read or update sub-transaction information.</entry>+ </row>+ <row>+ <entry><literal>SyncRepLock</literal></entry>+ <entry>Waiting to read or update information about synchronous+ replicas.</entry>+ </row>+ <row>+ <entry><literal>SyncScanLock</literal></entry>+ <entry>Waiting to get the start location of a scan on a table for+ synchronized scans.</entry>+ </row>+ <row>+ <entry><literal>TablespaceCreateLock</literal></entry>+ <entry>Waiting to create or drop the tablespace.</entry>+ </row>+ <row>+ <entry><literal>TwoPhaseStateLock</literal></entry>+ <entry>Waiting to read or update the state of prepared transactions.</entry>+ </row>+ <row>+ <entry><literal>WALBufMappingLock</literal></entry>+ <entry>Waiting to replace a page in WAL buffers.</entry>+ </row>+ <row>+ <entry><literal>WALWriteLock</literal></entry>+ <entry>Waiting for WAL buffers to be written to disk.</entry>+ </row>+ <row>+ <entry><literal>XidGenLock</literal></entry>+ <entry>Waiting to allocate or assign a transaction id.</entry>+ </row>+ <row>+ <entry><literal>async</literal></entry>+ <entry>Waiting for I/O on an async (notify) buffer.</entry>+ </row>+ <row>+ <entry><literal>buffer_content</literal></entry>+ <entry>Waiting to read or write a data page in memory.</entry>+ </row>+ <row>+ <entry><literal>buffer_io</literal></entry>+ <entry>Waiting for I/O on a data page.</entry>+ </row>+ <row>+ <entry><literal>buffer_mapping</literal></entry>+ <entry>Waiting to associate a data block with a buffer in the buffer+ pool.</entry>+ </row>+ <row>+ <entry><literal>clog</literal></entry>+ <entry>Waiting for I/O on a clog (transaction status) buffer.</entry>+ </row>+ <row>+ <entry><literal>commit_timestamp</literal></entry>+ <entry>Waiting for I/O on commit timestamp buffer.</entry>+ </row>+ <row>+ <entry><literal>lock_manager</literal></entry>+ <entry>Waiting to add or examine locks for backends, or waiting to+ join or exit a locking group (used by parallel query).</entry>+ </row>+ <row>+ <entry><literal>multixact_member</literal></entry>+ <entry>Waiting for I/O on a multixact_member buffer.</entry>+ </row>+ <row>+ <entry><literal>multixact_offset</literal></entry>+ <entry>Waiting for I/O on a multixact offset buffer.</entry>+ </row>+ <row>+ <entry><literal>oldserxid</literal></entry>+ <entry>Waiting for I/O on an oldserxid buffer.</entry>+ </row>+ <row>+ <entry><literal>parallel_append</literal></entry>+ <entry>Waiting to choose the next subplan during Parallel Append plan+ execution.</entry>+ </row>+ <row>+ <entry><literal>parallel_hash_join</literal></entry>+ <entry>Waiting to allocate or exchange a chunk of memory or update+ counters during Parallel Hash plan execution.</entry>+ </row>+ <row>+ <entry><literal>parallel_query_dsa</literal></entry>+ <entry>Waiting for parallel query dynamic shared memory allocation lock.</entry>+ </row>+ <row>+ <entry><literal>predicate_lock_manager</literal></entry>+ <entry>Waiting to add or examine predicate lock information.</entry>+ </row>+ <row>+ <entry><literal>proc</literal></entry>+ <entry>Waiting to read or update the fast-path lock information.</entry>+ </row>+ <row>+ <entry><literal>replication_origin</literal></entry>+ <entry>Waiting to read or update the replication progress.</entry>+ </row>+ <row>+ <entry><literal>replication_slot_io</literal></entry>+ <entry>Waiting for I/O on a replication slot.</entry>+ </row>+ <row>+ <entry><literal>serializable_xact</literal></entry>+ <entry>Waiting to perform an operation on a serializable transaction+ in a parallel query.</entry>+ </row>+ <row>+ <entry><literal>subtrans</literal></entry>+ <entry>Waiting for I/O on a subtransaction buffer.</entry>+ </row>+ <row>+ <entry><literal>tbm</literal></entry>+ <entry>Waiting for TBM shared iterator lock.</entry>+ </row>+ <row>+ <entry><literal>wal_insert</literal></entry>+ <entry>Waiting to insert WAL into a memory buffer.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>++ <table id="wait-event-timeout-table">+ <title>Wait Events of Type <literal>Timeout</literal></title>+ <tgroup cols="2">+ <thead>+ <row>+ <entry><literal>Timeout</literal> Wait Event</entry>+ <entry>Description</entry>+ </row>+ </thead>++ <tbody>+ <row>+ <entry><literal>BaseBackupThrottle</literal></entry>+ <entry>Waiting during base backup when throttling activity.</entry>+ </row>+ <row>+ <entry><literal>PgSleep</literal></entry>+ <entry>Waiting in process that called <function>pg_sleep</function>.</entry>+ </row>+ <row>+ <entry><literal>RecoveryApplyDelay</literal></entry>+ <entry>Waiting to apply WAL at recovery because it is delayed.</entry>+ </row>+ <row>+ <entry><literal>RecoveryRetrieveRetryInterval</literal></entry>+ <entry>Waiting when WAL data is not available from any kind of sources+ (<filename>pg_wal</filename>, archive or stream) before trying+ again to retrieve WAL data, at recovery.</entry>+ </row>+ <row>+ <entry><literal>VacuumDelay</literal></entry>+ <entry>Waiting in a cost-based vacuum delay point.</entry>+ </row>+ </tbody>+ </tgroup>+ </table>
<note>
<para>
@@ -3728,7 +3912,8 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
</para>
<para>
Returns the wait event name if this backend is currently waiting,
- otherwise NULL. See <xref linkend="wait-event-table"/> for details.+ otherwise NULL. See <xref linkend="wait-event-activity-table"/> through+ <xref linkend="wait-event-timeout-table"/>.
</para></entry>
</row>
=
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-docs@postgresql.org
Cc: tgl@sss.pgh.pa.us, pgsql-docs@lists.postgresql.org
Subject: Re: Remaining PDF layout issues
In-Reply-To: <26961.1589260206@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox