I have never heard of pg_pause_recovery() or pg_resume_recovery(). However, you can use pg_xlog_replay_pause() and pg_xlog_replay_resume() to pause and resume recovery. As Sameer mentioned, they require the system to be in hot standby mode to use them.
Sorry, I used the functions names used in code (my bad). Thanks for pointing out it is
pg_xlog_replay_pause() and pg_xlog_replay_resume()
Best Regards,
Sameer Kumar | Database Consultant
ASHNIK PTE. LTD.
101 Cecil Street, #11-11 Tong Eng Building, Singapore 069533