PostgreSQL自带的命令行工具22- pg

PostgreSQL自带的命令行工具22- pg_controldata

基础信息
OS版本：Red Hat Enterprise Linux Server release 7.9 (Maipo)
DB版本：16.2
pg软件目录：/home/pg16/soft
pg数据目录：/home/pg16/data
端口：5777

pg_controldata 是 PostgreSQL 提供的一个实用工具，用于显示 PostgreSQL 数据库集群的控制信息。这个实用程序可以让你查看一些关键的系统信息，而不必启动数据库服务器。这些信息对于故障排除、监控和理解 PostgreSQL 数据库的内部运行机制非常有价值。

通过help查看帮助文档。

[pg16@test ~]$ pg_controldata --help
pg_controldata displays control information of a PostgreSQL database cluster.Usage:pg_controldata [OPTION] [DATADIR]Options:[-D, --pgdata=]DATADIR  data directory-V, --version          output version information, then exit-?, --help             show this help, then exitIf no data directory (DATADIR) is specified, the environment variable PGDATA
is used.Report bugs to <pgsql-bugs@lists.postgresql.org>.
PostgreSQL home page: <https://www.postgresql.org/>

使用 pg_controldata

要使用 pg_controldata，只需要在命令行中指定你的 PostgreSQL 数据目录。数据目录是在初始化数据库集群时 (initdb) 指定的目录，它包含了所有的数据库文件、事务日志以及其他重要的系统文件。

命令格式如下：

pg_controldata [选项] 数据目录

如果没有指定任何选项和数据目录，pg_controldata 将尝试使用环境变量 PGDATA。

示例

PostgreSQL 数据目录位于 /home/pg16/data/，运行以下命令：

[pg16@test ~]$ pg_controldata -D /home/pg16/data/
pg_control version number:            1300
Catalog version number:               202307071
Database system identifier:           7355755036767920482
Database cluster state:               in production
pg_control last modified:             Sun 12 May 2024 07:32:38 AM PDT
Latest checkpoint location:           0/6F000028
Latest checkpoint's REDO location:    0/6F000028
Latest checkpoint's REDO WAL file:    00000001000000000000006F
Latest checkpoint's TimeLineID:       1
Latest checkpoint's PrevTimeLineID:   1
Latest checkpoint's full_page_writes: on
Latest checkpoint's NextXID:          0:268784
Latest checkpoint's NextOID:          17008
Latest checkpoint's NextMultiXactId:  1
Latest checkpoint's NextMultiOffset:  0
Latest checkpoint's oldestXID:        722
Latest checkpoint's oldestXID's DB:   4
Latest checkpoint's oldestActiveXID:  0
Latest checkpoint's oldestMultiXid:   1
Latest checkpoint's oldestMulti's DB: 16535
Latest checkpoint's oldestCommitTsXid:0
Latest checkpoint's newestCommitTsXid:0
Time of latest checkpoint:            Sat 11 May 2024 07:31:17 AM PDT
Fake LSN counter for unlogged rels:   0/3E8
Minimum recovery ending location:     0/0
Min recovery ending loc's timeline:   0
Backup start location:                0/0
Backup end location:                  0/0
End-of-backup record required:        no
wal_level setting:                    replica
wal_log_hints setting:                off
max_connections setting:              100
max_worker_processes setting:         8
max_wal_senders setting:              10
max_prepared_xacts setting:           0
max_locks_per_xact setting:           64
track_commit_timestamp setting:       off
Maximum data alignment:               8
Database block size:                  8192
Blocks per segment of large relation: 131072
WAL block size:                       8192
Bytes per WAL segment:                16777216
Maximum length of identifiers:        64
Maximum columns in an index:          32
Maximum size of a TOAST chunk:        1996
Size of a large-object chunk:         2048
Date/time type storage:               64-bit integers
Float8 argument passing:              by value
Data page checksum version:           1
Mock authentication nonce:            cd0bbc02ebd6164eb7f1a9fce1c0b244c8139fa55343101e301b395c35fa9db0