[Zope] best postgreSQL adapter?

[Federico Di Gregorio]

> if you're going to be connect to postgres outside of zope i recommend not
> using PoPy. Its regularly crashes python for me when i try to do things any
> heavy db work from outside zope. heavy constituting using bind variables,
> stored procs, checking rowcount, description, etc. in accessing postgres
> external to zope i'd recommend using pygresql (the native non-standard
> interface not the dbi wrapper) or pgsql.

while it still does not support direct call of stored procedures using
callproc(), psycopg is pretty stable on bind variables and also offers
a very nice type-casting system to convers postgres results to custom
python types. 

> one thing to not about ZPygre is that it synchronizes all db access. if

this is bad, because you can't rollback...

> you're making lots of small queries this is not the adaptor for you. if
> you've got some large queries you're better off testing both and seeing which
> one gives you better throughput (probably PoPy, buts it not a sure thing).

i am very interested in drivers performance: has anybody set up a test
of some kind to test this stuff? we use a simple test with 3 threads
doing simultaneous INSERTs and SELECTs, creating lots of cursors and
psycopg seems pretty fast but i would better like some *real* test.
 
> >>any others?  psycopg mentions that it is designed for heavy multi threaded
> >>operations but popy seems more developed.
> 
> psycopg has interesting arch, but if you're using postgres its good to keep
> in mind that libpq (the c client interface to postgres) does not support
> multiple threads sharing a connection. psycopg does internal bookeeping in

that's why we came out with the "interesting arch" :) note that psycopg
does it better when you create lots of short-lived threads all using
the same connection and creating one or more cursor each.

> the module itself after a connect to keep around a pool of connections. when
> it matures it should be a very good postgres adaptor for zope.

ok, we wrote it in about 4 weeks, but let me say that psycopg is already
pretty stable. we know at least 1 company that switched its production site 
from another driver (i won't say what) to psycopg because they had
stability problems... i am glad to say that the problems are now resolved
(mmm... or, maybe, psycopg simply destroyed their entire production server,
i can't say... :)

jokes apart, a new product can't mature if nobody use it because it is
"still young", so try it out and send bug reports, thanx!

federico 

-- 
Federico Di Gregorio
MIXAD LIVE Chief of Research & Technology              fog@mixadlive.com
Debian GNU/Linux Developer & Italian Press Contact        fog@debian.org
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