Re: [Modeling-users] Fetching raw rows

[Sebastien B. <sbi...@us...>]

Sebastien Bigaret <sbi...@us...> wrote:

> [std] 1st fetch : 7.20251297951
> [std] 2nd fetch : 1.03094005585
>=20
> [raw row] 1st fetch (ec empty):                0.618131995201
> [raw row] 2nd fetch (objects already loaded):  0.61448597908
> [raw row] 3rd fetch (objects already loaded):  2.24008309841
>=20
> [psycopg] 1st fetch: 0.038547039032
> [psycopg] 2nd fetch: 0.0789960622787

I guess I had no chance when running [std], i.e. standard
EditingContext.fetch() on 5000 objects. Here are corrected figures, average
for 5 executions:

Python2.1
---------
normal:    [std] 1st fetch : 6.74
           [std] 2nd fetch : 0.96
=20=20=20=20=20=20=20=20
python -O: [std] 1st fetch : 6.25
           [std] 2nd fetch : 0.91

Python2.2
---------
normal:    [std] 1st fetch : 5.80
           [std] 2nd fetch : 0.90
=20=20=20=20=20=20=20=20
python -O: [std] 1st fetch : 5.30
           [std] 2nd fetch : 0.83


By curiosity, I played ~20 minutes w/ psyco. After some tries, with the
following code on top on the script:

------------------------------------------------------------------------
from threading import _RLock
from Modeling.DatabaseContext import DatabaseContext
from Modeling.DatabaseChannel import DatabaseChannel
from Modeling.ClassDescription import classDescriptionForName
psyco.bind(DatabaseContext.initializeObject)
psyco.bind(DatabaseChannel.fetchObject)
psyco.bind(classDescriptionForName)
psyco.bind(_RLock.acquire)
psyco.bind(_RLock.release)
------------------------------------------------------------------------

I got the following figure:

Python2.1+psycho
----------------
normal:    [std] 1st fetch : 5.70
           [std] 2nd fetch : 0.81

python -O: [std] 1st fetch : 5.52
           [std] 2nd fetch : 0.79

Python2.2+psycho
----------------
normal:    [std] 1st fetch : 4.32
           [std] 2nd fetch : 0.72

python -O: [std] 1st fetch : 4.21
           [std] 2nd fetch : 0.68


  Note on psycho: this was just tuned for fetching, and for fetching
    with very simple objects, that's all. This would need further
    investigation, obviously. But since I tried it, I thought I could
    share, I find it amazing to be able to get a significant performance
    imrpovement just a few minutes after having installed it.

That's more meat for the forthcoming 'tuning performance' section in the
guide. As a general conclusion, py2.2 is faster than py2.1, and the '-O'
option is definitively worth the try.

  BTW: who is using the framework w/ python2.1 alone? And with py2.1 and
  (because of) zope?

-- S=E9bastien.