docs log_executor_stats

Hi,

is there any documentation about the output of "log_executor_stats=on" out
there?
it seems quite intuitiv on the first glance, but ....
if you are at the point reading this output, you are already quite deep in
the system and have problems. And I need to know what each of the numbers
really not probably mean.

i know what a context switch is or a page fault/reclaim, etc.
what i need to know is the context of the numbers:
- numbers without brackets
- number with brackets
- context for those numbers: are all of these numbers one-to-one related to
my function call? Or did those numbers (signals/page reclaims) come up
during the time of execution of that function?

what I don't know and never found so far is "Local blocks" and "Direct
blocks". So I'd be interested to know what's this, jst for completeness.

please help!!!!!

thanks,
Uwe

LOG: EXECUTOR STATISTICS
DETAIL: ! system usage stats:
! 34.228987 elapsed 7.561851 user 1.594757 system sec
! [7.719826 user 1.633751 sys total]
! 0/0 [0/0] filesystem blocks in/out
! 0/267488 [0/276350] page faults/reclaims, 0 [0] swaps
! 0 [0] signals rcvd, 0/0 [0/0] messages rcvd/sent
! 4058/115 [4084/115] voluntary/involuntary context switches
! buffer usage stats:
! Shared blocks: 5336 read, 0 written, buffer hit rate
= 99.65%
! Local blocks: 0 read, 0 written, buffer hit rate
= 0.00%
! Direct blocks: 0 read, 0 written
LOG: duration: 34229.811 ms statement: select * from testfunction(462041,
0::smallint);

Uwe Bartels <uwe(dot)bartels(at)gmail(dot)com> writes:
> i know what a context switch is or a page fault/reclaim, etc.
> what i need to know is the context of the numbers:
> - numbers without brackets
> - number with brackets

It looks like the numbers in brackets are the latest raw numbers from
getrusage(), whereas the numbers before the brackets are the delta
from a getrusage() call made at the start of execution.

> - context for those numbers: are all of these numbers one-to-one related to
> my function call? Or did those numbers (signals/page reclaims) come up
> during the time of execution of that function?

It's just the overall getrusage result for the backend process.

> what I don't know and never found so far is "Local blocks" and "Direct
> blocks". So I'd be interested to know what's this, jst for completeness.

Local blocks are (or were ... that code is gone as of 9.0) I/O for
temporary tables of the current backend. I think direct blocks was a
count of I/Os on temp files (sort data and so on).

regards, tom lane