Re: gettimeofday is at the end of its usefulness?

On Tue, May 13, 2014 at 06:58:11PM -0400, Tom Lane wrote:
> A recent question from Tim Kane prompted me to measure the overhead
> costs of EXPLAIN ANALYZE, which I'd not checked in awhile.  Things
> are far worse than I thought.  On my current server (by no means
> lavish hardware: Xeon E5-2609 @2.40GHz) a simple seqscan can run
> at something like 110 nsec per row:

I assume you ran pg_test_timing too:

	Testing timing overhead for 3 seconds.
	Per loop time including overhead: 41.70 nsec
	Histogram of timing durations:
	< usec   % of total      count
	     1     95.83035   68935459
	     2      4.16923    2999133
	     4      0.00037        268
	     8      0.00004         31
	    16      0.00000          1
	    32      0.00000          1

My overhead of 41.70 nsec matches yours.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +