postgresql 查看数据库集群创建时间

使用 pg_controldata 查看 Database system identifier

$ /usr/pgsql-10/bin/pg_controldata -D /var/lib/pgsql/10/data/
pg_control version number:            1002
Catalog version number:               201707211
Database system identifier:           6571787082216241690
Database cluster state:               in production
pg_control last modified:             Thu 05 Jul 2018 05:17:31 PM CST
Latest checkpoint location:           0/16D3DE0
Prior checkpoint location:            0/16D3D00
Latest checkpoint's REDO location:    0/16D3DA8
Latest checkpoint's REDO WAL file:    000000010000000000000001

执行下面sql

peiybdb=# select version();
                                                 version                                                 
---------------------------------------------------------------------------------------------------------
 PostgreSQL 10.4 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-28), 64-bit
(1 row)

peiybdb=# SELECT to_timestamp(((6571787082216241690>>32) &(2^32 -1)::bigint));
      to_timestamp      
------------------------
 2018-06-27 23:30:16+08
(1 row)