log_line_prefix is a GUC parameter determining the format of the first part of each log line.
log_line_prefix was added in PostgreSQL 8.0.
Default
The default value for log_line_prefix is '%m [%p] ' (PostgreSQL 10 and later; prior to that it was an empty string).
Change history
- PostgreSQL 14
%Pparameter added to show the parallel group leader (commit b8fdee7d)
- PostgreSQL 13
%bparameter added to show the backend type (commit 70a7b477)
- PostgreSQL 10
- default changed from empty string to '
%m [%p]' (commit 7d3235ba)
- default changed from empty string to '
- PostgreSQL 9.6
%nparameter added to show the Unix epoch (commit f828654e)
- PostgreSQL 9.4
printf-style padding specifications permitted (commit 4334639f)
- PostgreSQL 9.0
%eparameter added to show the current SQL state (commit f39df967)
- PostgreSQL 8.0
- added (commit 2d3fe86b)
References
- PostgreSQL documentation: log_line_prefix