[PYTHON DB-SIG] Python vs Perl DB API

aaron watters aaron_watters@msn.com
Wed, 5 Feb 97 23:27:22 UT

Without the code it's hard to say, but I'd assume there may be some
room for improvement in your code, as I haven't seen it :).

One thing you should do right away is, if you are doing everything
at a global level, try just enclosing the whole thing in a function.
This can get a 2x speedup when lots of variable references are made
-- and it's even faster if you forget to execute the function!

There are lots of ways to format text poorly in Python.  At the risk
of chastisement ;) I'd suggest that some sections (Playing and Generating
HTML) which I wrote in Internet Programming with Python (book)
describe text formatting in detail - although blinding speed isn't always
the focus.  Maybe try formatting the data in larger chunks (using
s % tuple and string.joinfields etc) and writing directly to sys.stdout.
In my oracle grub days I used to load 100000 tuples 
(lst=curs.fetchmany(100000)) at once, l = map(fmter, lst)  mapping a
formatter function across them and slam them out to a file using
sys.stdout.write(string.joinfields(l, "\n")).  I thought this screamed.

In general I don't think Python 1.4 properly used is significantly slower than 
but in the special case of simple text formatting Perl probably is faster --
after all that's what it was designed to do originally.  - Aaron Watters

From:  owner-db-sig@python.org on behalf of Orjan Reinholdsen
Sent:  Wednesday, February 05, 1997 12:47 PM
To:  db-sig@python.org
Subject:  [PYTHON DB-SIG] Python vs Perl DB API


Lately, I'v left Perl behind and I'm now using Python (and 
'oracledb') to interface our Oracle DB. Generally this works great 
and I really adore the Python syntax compared to Perl, but now I'v 
run into some questions regarding speed:

I'v timed the execution of a Perl script and a Python script 
doing the same thing, with the result that the Perl script is 
roughly 3 times faster that the Python script. I should note that the 
DB operations in the scripts involves a select and the formating 
of roughly 2500 lines of text output (mainly using 'print'). 

So the question arise: Why is the Python script significantly slower 
than the Perl script? Is it because of the  "speed" of 'oracledb' 
and/or the Python DB API, or is it because Python is generically 
slower that Perl? Any suggestions for speed improvement??

Happy for ANY answer.

Orjan Reinholdsen
 Orjan Reinholdsen                                      Infopartners SA 
 Voice: +352 29 57 59 33 02                             Fax: +352 29 57 59 39 
 e-mail: orjan@ip.lu

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