On Thu, Oct 26, 2017 at 10:20 PM, Weiping Qu <qu@xxxxxxxxxxxxxxxxxxxx> wrote: > However, the plots showed different trend (currently I don't have plots on > my laptop) which shows that the more frequently are the CDC processes > reading from logical slots, the less overhead is incurred over PostgreSQL, > which leads to higher throughput. Have you accounted for disk caching? Your CDC may be getting log from the cache when going with little lag but being forced to read from disk (make the server do it ) when it falls behind. Francisco Olarte. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general