May 2018
Intermediate to advanced
576 pages
30h 25m
English
Changes made by a transaction on the master will not be visible until the commit is applied onto the standby. So, for example, we have a master and a standby with a replication delay of four seconds between them. A long-running transaction may write changes to the master for one hour. How long does it take before those changes are visible on the standby? With Hot Standby, the answer is four seconds after the commit on the master. This is because the changes made during the transaction on the master are streamed while the transaction is still in progress, and in most cases, they are already applied on the standby when the commit record arrives.
You may also wish to use the remote_apply mode; see the Delaying, pausing, and synchronizing ...