如何显示数据库文件信息？

答：gs_controldata工具用来显示数据库数据目录下pg_control文件的信息。

--查看gs_controldata工具的版本信息。
[omm1@node41 ~]$ gs_controldata -V
gs_controldata (GaussDB Kernel 505.2.RC1 build 939a176f) compiled at 2024-04-30 20:05:50 last mr 17511 release

--查找pg_control文件所在的路径。
[root@node41 ~]# find / -name pg_control
/opt/software/db5052/gaussdb/data/slave31/global/pg_control
/opt/software/db5052/gaussdb/data/coordinator/global/pg_control
/opt/software/db5052/gaussdb/data/master1/global/pg_control
/opt/software/db5052/gaussdb/data/slave21/global/pg_control

--这里以master1目录为例，查看pg_control文件的信息，DATADIR路径需写到上面查询出的路径的data层的下一层目录。
[omm1@node41 ~]$ gs_controldata /opt/software/db5052/gaussdb/data/master1
pg_control version number:            923
Catalog version number:               201611171
Database system identifier:           18020659789221943256
Database cluster state:               in production
pg_control last modified:             Sat 11 May 2024 10:43:58 AM CST
Latest checkpoint location:           0/134044D8
Prior checkpoint location:            0/13403BB8
Latest checkpoint's REDO location:    0/13404458
Latest checkpoint's TimeLineID:       1
Latest checkpoint's full_page_writes: off
Latest checkpoint's NextXID:          70025
Latest checkpoint's NextOID:          24576
Latest checkpoint's NextMultiXactId:  2
Latest checkpoint's NextMultiOffset:  0
Latest checkpoint's oldestXID:        3
Latest checkpoint's oldestXID's DB:   2
Latest checkpoint's oldestActiveXID:  70025
Latest checkpoint's remove lsn:          0/1
Time of latest checkpoint:            Sat 11 May 2024 10:43:57 AM CST
Minimum recovery ending location:     0/0
Backup start location:                0/0
Backup end location:                  0/0
End-of-backup record required:        no
Current wal_level setting:            hot_standby
Current max_connections setting:      1084
Current max_prepared_xacts setting:   800
Current max_locks_per_xact setting:   256
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
Date/time type storage:               64-bit integers
Float4 argument passing:              by value
Float8 argument passing:              by value
Database system TimeLine:             1