PostgreSQL唯一安装ID

Question

Where can I get Postgresql unique installation ID? like...

SELECT dbid from v$database; (in oracle)

I need it to identify my different database installation across different sites. Getting MAC id of server is a way but if there is a way to get it from postgresql it would be preferred.

Answer 1

if you have replication slot available, you can use IDENTIFY_SYSTEM :

MacBook-Air:~ vao$ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;"
Timing is on.
Pager usage is off.
      systemid       | timeline |  xlogpos   |  dbname
---------------------+----------+------------+----------
 6401169876745218982 |        1 | 1/7A470D80 | postgres
(1 row)