commit_delay is a configuration parameter for adding a time delay before a WAL flush is initiated.
commit_delay was added in PostgreSQL 7.1.
The default value for
If set to a non-zero value,
commit_delay makes it possible for a larger number of transactions to commit via a single WAL flush, improving system throughput. Howeve it t also increases latency by up to the specified value for each WAL flush.
commit_delay is only of practical use if mulitple transactions (at least the number specified by
5) become ready to commit within the interval specified.