Re: RFC: built-in historical query time profiling

"Ed L." <pgsql(at)bluepolka(dot)net> writes:
> ... We can do
> this by writing programs to periodically parse log files for
> queries and durations, and then centralizing that information
> into a db for analysis, similar to pqa's effort.

That strikes me as exactly what you ought to be doing.

> Suppose there were some sort of system relations like these:

This is going to fall down on exactly the same objections that have been
made to putting the log messages themselves into tables. The worst one
is that a failed transaction would fail to make any entry whatsoever.
There are also performance, locking, and security issues to think about.
(Example: heaven help you if someone decides to VACUUM FULL the log
table --- that would block every other process due to exclusive lock.)

regards, tom lane