[Zope-dev] [Q] Pickle support for C wrapper and ZEO

[Ames Andreas (MPA/DF)]

Hi all,

I'm reposting here because I had no luck on zope at zope.org.

I'm in the course of low-level wrapping the ODBC api.  Just in case
you wonder:  I know of mxODBC and pyodbc, they don't fit my needs as
well license-wise as technically (I want better metadata access,
thread-safety etc.).

I'll use my wrapper from within Zope.  There will be some python
wrapper around the low-level stuff and I wonder if it makes sense to
add pickle-support to that python wrapper.

The ODBC api is object-based and exhibits four object types:
environment, connection, statement and descriptor objects each of
which has a set of methods and properties.  Pickle-wise I'm not so
concerned about persistence across shutdown/restart cycles (I think
it's reasonable to re-create your ODBC environments, connections
etc. after restart) but rather about consistency across ZEO-instances.
My lack of experience makes me ask here for expert advise.

1)  Does the ZEO scenario demand some pickle support, e. g. to
    use consitent environments/connections etc. across ZEO instances
    or do I just misunderstand ZEO?

2)  If pickle support is a good idea:  What scope would you find
    reasonable?  I. e. I can imagine that persistence of
    environments/descriptors could be useful while persistent
    connections/statements could cause more trouble than they are
    worth.

As you can see the whole thing isn't very clear to me and so I'd
appreciate your comments.


TIA,

andreas