Re: RFC: built-in historical query time profiling

"Ed L." <pgsql@bluepolka.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