STATISTICS VIEW · 统计视图

pg_stat_replication

The pg_stat_replication view will contain one row per WAL sender process, showing statistics about replication to that sender's connected standby server. Only directly connected standbys are listed; no information is available about downstream standby servers. The lag times reported in the pg_stat_replication view are measurements of the time taken for recent WAL to be written, flushed and replayed and for the sender to know about it. These times represent the commit delay that was (or would have been) introduced by each synchronous commit level, if the remote server was configured as a synchronous standby. For an asynchronous standby, the replay_lag column approximates the delay before recent transactions became visible to queries. If the standby server has entirely caught up with the sending server and there is no more WAL activity, the most recently measured lag times will continue to be displayed for a short time and then show NULL. Lag times work automatically for physical replication. Logical decoding plugins may optionally emit tracking messages; if they do not, the tracking mechanism will simply display NULL lag.

首次收录 PG 9.1最近收录 PG 19当前字段 20

9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19^β3

已与 PostgreSQL 18.6 实例逐字段核对 · 原始实测记录 ↗

字段结构 PostgreSQL 18

pg_stat_replication

字段 / COLUMN	类型 / TYPE	说明 / DESCRIPTION
`pid`	`integer`	Process ID of a WAL sender process
`usesysid`	`oid`	OID of the user logged into this WAL sender process
`usename`	`name`	Name of the user logged into this WAL sender process
`application_name`	`text`	Name of the application that is connected to this WAL sender
`client_addr`	`inet`	IP address of the client connected to this WAL sender. If this field is null, it indicates that the client is connected via a Unix socket on the server machine.
`client_hostname`	`text`	Host name of the connected client, as reported by a reverse DNS lookup of client_addr. This field will only be non-null for IP connections, and only when log_hostname is enabled.
`client_port`	`integer`	TCP port number that the client is using for communication with this WAL sender, or -1 if a Unix socket is used
`backend_start`	`timestamp with time zone`	Time when this process was started, i.e., when the client connected to this WAL sender
`backend_xmin`	`xid`	This standby's xmin horizon reported by hot_standby_feedback.
`state`	`text`	Current WAL sender state. Possible values are:
`sent_lsn`	`pg_lsn`	Last write-ahead log location sent on this connection
`write_lsn`	`pg_lsn`	Last write-ahead log location written to disk by this standby server
`flush_lsn`	`pg_lsn`	Last write-ahead log location flushed to disk by this standby server
`replay_lsn`	`pg_lsn`	Last write-ahead log location replayed into the database on this standby server
`write_lag`	`interval`	Time elapsed between flushing recent WAL locally and receiving notification that this standby server has written it (but not yet flushed it or applied it). This can be used to gauge the delay that synchronous_commit level remote_write incurred while committing if this server was configured as a synchronous standby.
`flush_lag`	`interval`	Time elapsed between flushing recent WAL locally and receiving notification that this standby server has written and flushed it (but not yet applied it). This can be used to gauge the delay that synchronous_commit level on incurred while committing if this server was configured as a synchronous standby.
`replay_lag`	`interval`	Time elapsed between flushing recent WAL locally and receiving notification that this standby server has written, flushed and applied it. This can be used to gauge the delay that synchronous_commit level remote_apply incurred while committing if this server was configured as a synchronous standby.
`sync_priority`	`integer`	Priority of this standby server for being chosen as the synchronous standby in a priority-based synchronous replication. This has no effect in a quorum-based synchronous replication.
`sync_state`	`text`	Synchronous state of this standby server. Possible values are:
`reply_time`	`timestamp with time zone`	Send time of last reply message received from standby server

标记“隐式列”的字段不包含在 SELECT * 中；部分早期统计视图由同版本源码补全，额外来源会显示在字段说明中。

字段演化矩阵

悬停查看字段类型

存在新增 / 类型或属性变化移除

字段 / COLUMN	9.0	9.1	9.2	9.3	9.4	9.5	9.6	10	11	12	13	14	15	16	17	18	19
`procpid`	–		−	–	–	–	–	–	–	–	–	–	–	–	–	–	–
`usesysid`	–
`usename`	–
`application_name`	–
`client_addr`	–
`client_hostname`	–
`client_port`	–
`backend_start`	–
`state`	–
`sent_location`	–							−	–	–	–	–	–	–	–	–	–
`write_location`	–							−	–	–	–	–	–	–	–	–	–
`flush_location`	–							−	–	–	–	–	–	–	–	–	–
`replay_location`	–							−	–	–	–	–	–	–	–	–	–
`sync_priority`	–
`sync_state`	–
`pid`	–	–
`backend_xmin`	–	–	–	–
`sent_lsn`	–	–	–	–	–	–	–
`write_lsn`	–	–	–	–	–	–	–
`flush_lsn`	–	–	–	–	–	–	–
`replay_lsn`	–	–	–	–	–	–	–
`write_lag`	–	–	–	–	–	–	–
`flush_lag`	–	–	–	–	–	–	–
`replay_lag`	–	–	–	–	–	–	–
`reply_time`	–	–	–	–	–	–	–	–	–

9.0 是收录基线；基线中已存在的字段不标记为新增。矩阵按字段名称对齐，重命名显示为旧字段移除与新字段新增。

演化时间线

相邻大版本的变化

PostgreSQL 19 ← 18

1 处字段说明更新

PostgreSQL 13 ← 12

2 处字段说明更新目录说明更新

PostgreSQL 12 ← 11

+ reply_time目录说明更新

PostgreSQL 10 ← 9.6

+ sent_lsn+ write_lsn+ flush_lsn+ replay_lsn+ write_lag+ flush_lag+ replay_lag− sent_location− write_location− flush_location− replay_location3 处字段说明更新目录说明更新

PostgreSQL 9.6 ← 9.5

目录说明更新

PostgreSQL 9.5 ← 9.4

目录说明更新

PostgreSQL 9.4 ← 9.3

+ backend_xmin~ flush_location: text → pg_lsn~ replay_location: text → pg_lsn~ sent_location: text → pg_lsn~ write_location: text → pg_lsn目录说明更新

PostgreSQL 9.2 ← 9.1

+ pid− procpid1 处字段说明更新目录说明更新

PostgreSQL 9.1 ← 9.0新增目录

+ procpid+ usesysid+ usename+ application_name+ client_addr+ client_hostname+ client_port+ backend_start+ state+ sent_location+ write_location+ flush_location+ replay_location+ sync_priority+ sync_state

比较任意两个版本

起始版本 / FROM目标版本 / TO包含描述更新

选择两个版本，查看字段的新增、移除与类型变化。交互比较需要 JavaScript；演化时间线可直接阅读。