PostgreSQL 11 Administration Cookbook

How to do it…

Normally, a standby will apply changes as soon as possible. When you set the recovery_min_apply_delay parameter in recovery.conf, the application of commit records will be delayed by the specified duration. Note that only commit records are delayed, so you may receive hot standby cancellations when using this feature. You can prevent that by setting hot_standby_feedback to on, but use this with caution, since it can cause significant bloat on a busy master if recovery_min_apply_delay is large.

If something bad happens, then hit the Pause button.

Hot standby allows you to pause and resume a replay of change:

1. To pause the replay, issue this query:

SELECT pg_wal_replay_pause();

Once paused, all queries will receive the same snapshot, ...