Aug
25
pg_controldata
I found a nice PostgreSQL command the other day: pg_controldata. Takes one argument (the path to the data directory) and returns a whole bunch of useful information about the instance. This’ll be useful for determining how up to date a PostgreSQL warm standby database is. See the line below labeled “Time of latest checkpoint.” There’s other useful information in the output:
[root@localhost data]# pg_controldata /usr/local/pgsql/data
pg_control version number: 833
Catalog version number: 200711281
Database system identifier: 5187205705949378879
Database cluster state: in archive recovery
pg_control last modified: Mon 25 Aug 2008 02:12:08 PM EDT
Latest checkpoint location: 0/1A7CCD44
Prior checkpoint location: 0/167A4728
Latest checkpoint's REDO location: 0/190006A0
Latest checkpoint's TimeLineID: 1
Latest checkpoint's NextXID: 0/679574
Latest checkpoint's NextOID: 24581
Latest checkpoint's NextMultiXactId: 1
Latest checkpoint's NextMultiOffset: 0
Time of latest checkpoint: Mon 25 Aug 2008 02:01:38 PM EDT
Minimum recovery ending location: 0/C81D500
Maximum data alignment: 4
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: 2000
Date/time type storage: floating-point numbers
Maximum length of locale name: 128
LC_COLLATE: en_US.UTF-8
LC_CTYPE: en_US.UTF-8
Thanks to http://www.kennygorman.com/wordpress/?p=249 for the idea.
