On 17 June 2015 at 15:36, Prakash Itnal <prakash074@gmail.com> wrote:
> Hi,
>
> Currently we observed that certain postgres child process, for eg.
> autovacuum worker, are not working as expected if there is a system time
> change. So I wanted to know if postgres already supports system time changes
> or not.
In general, small time slews will have no effect on operations. If
they do then that's likely a PostgreSQL bug.
A large time discontinuity, where time jumps backwards or forwards by
a large amount, could well cause issues. I would personally be
inclined to restart the database server in these cases, or kill the
autovaccum scheduler to force it to restart.
In what way are the autovacuum workers "not working as expected" after
a system time change? What was the system time change made? How was
the change made? On what operating system and version?
BTW, this seems to be posted on Stack Overflow too:
http://stackoverflow.com/questions/30839163/system-time-change-impact-to-postgresql-database-processes
-- Craig Ringer http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services