3.8. Backing up PostgreSQL database

If you plan to backup PostgreSQL database using pg_dump, pg_basebackup or any other tools, we strongly recommend to run the commands against PostgreSQL directly. As Pgpool-II is a proxy software, it gives an overhead for relaying message packets. Since obtaining a backup tends to produce lots of packets, performing backup through Pgpool-II will be slow compared with directly connecting PostgreSQL unless the database is very small.

Moreover, parallel pg_dump raises error if it is executed through Pgpool-II because the command handles snapshot id, which is a database depending object.

In most cases you want to choose primary server as the backup target. If you want backup standby server, you have to be very careful in choosing the right PostgreSQL server to obtain a backup because if the data is outdated, you are likely to have outdated database backup. You can use SHOW POOL NODES or pcp_node_info to know how the standby server catches up the primary server.