Why does PostgreSQL accept connections during recovery?

Question

Why does PostgreSQL accept connections during recovery?
I wanted to use ps_isready to determine if my database is done recovering from a backup and ready to accept connections. But it says the database is ready long before it is actually done recovering.
I now check if the recovery.signal file exists, but I wonder if there is a "better" way to determine if it is done recovering.

Answer 1

Two options come to my mind:

1. connect and check if PostgreSQL is no longer in recovery mode:

   psql -Atq -c 'SELECT pg_is_in_recovery()'
   

   • if the connection fails, PostgreSQL isn't up

   • if the result is t, PostgreSQL is recovering

   • if the result is f, PostgreSQL is done with recovery.

2. set hot_standby = off in postgresql.conf

   Then PostgreSQL won't allow connections in recovery mode.