Re: That EXPLAIN ANALYZE patch still needs work

Tom Lane wrote:

> If anyone else is still following this discussion, could you try the
> test case Simon gave a bit earlier (select count(*) from 100000-row
> table, check \timing with and without explain analyze)? If we could get
> a clearer picture of which platforms show the problem and which don't,
> maybe we could make some progress.

Tried on two machines. The first (Turion64 laptop) gives 44-45 ms for
the SELECT, and 50-51 ms for the EXPLAIN ANALYZE.

The second machine, desktop Celeron 533, gives 197-200 ms for the SELECT
and 788-790 for the EXPLAIN ANALYZE. I guess this is the reproduction
you were looking for.

All results are repeated multiple times, I'm reporting times other than
the first query (which is slower).

More specs on the Celeron machine follow:

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 6
model name : Celeron (Mendocino)
stepping : 5
cpu MHz : 534.616
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 mmx fxsr
bogomips : 1070.25

$ uname -a
Linux drizzt 2.6.16-1-686 #2 Sat Apr 15 20:45:20 UTC 2006 i686 GNU/Linux

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.