To use PostgreSQL replication it is necessary to change the wal_level from “minimal” to “hot_standby”. But, which impact does this change have on the amount of WAL actually written to disk? And which impacts does it have in performance? Many people have been asking this question in the past, so I thought I’d give it […]

When it comes to performance, people tend to forget some basic topics entirely. One of those topics is the impact of writing log files. No, in a typical OLTP workload the creation of log files is definitely not free (in terms of performance). Quite the opposite – having to write millions of lines into a […]

It has always been commonly known that settings max_connections to an insanely high value is not too good for performance. Generations of system administrators have followed this rule. Just out of curiosity I thought I’d give it a try to see, which impact setting max_connections in PostgreSQL  really has. Again we have used the same […]