On Apr 24, 2009, at 2:37 AM, Shane Hathaway wrote:
> Christian Theune wrote:
>> On Thu, 2009-04-23 at 15:02 -0700, David Glick wrote:
>>> Having now realized the folly of trying to split things into
>>> multiple databases, I would really like to merge these 3
>>> databases back into 1. Any ideas for how I could go about this?
>>> Based on
>>> and some experimentation, multi-database references are not
>>> supported by the import/export code. Do I have other options?
>> I think it should be possible to write a tool that merges one
>> into another. This needs some processing on the database objects as
>> their OIDs (and thus the internal references) need to be reorganized.
> The import machinery in ZODB/ExportImport.py provides a good example
> of how to rewrite OIDs. However, I am concerned that understanding
> that code requires a lot of experience with ZODB.
> David, if you want to tackle writing a tool that merges multi-
> databases by rewriting OIDs, it probably won't be easy, but I think
> you can count on help from this list. I also think the tool would
> be useful for others.
Taking the existing ExportImport.py code as a starting point, it looks
like I would need to:
1. modify the persistent_load method to handle rewriting extended
references of types 'n' and 'm'
2. provide some way to process several export files at once, and input
a mapping of filename to database name (to handle when I am, say,
importing 2 databases with references between each other)
Does this sound right? I'm not in any rush but I may tackle this if I
find time. It looks like OFS has a custom importer/exporter for XML
that I may be able to use as a model....hmm, though on closer
inspection this only rewrites the XML format into the standard format
and then uses the same _importDuringCommit implementation on the
Connection; it looks like I probably can't provide an alternate
_importDuringCommit without monkeypatching.
thanks all for the advice so far...
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