Laurence Rowe wrote: > Leonardo Santagada wrote: > >> Why doesn't zodb has a table of some form for this info? I heard that >> sometimes for very small objects the string containing this >> information can use up to 30% of the whole space of the file (using >> FileStorage). How does RelStorage store this? > > I believe this was what the python pickle protocol 2 was created for. > However I think when someone last looked the potential space savings > with real world data did not justify making the change (Hanno has a > branch in svn for this).
I tried out the protocol 2 format on its own. That only brings in advantages for new-style classes. My very informal tests didn't reveal any significant improvements. My use-case is storing document centric data in the ZODB, in which case the actual payload will always be a lot larger compared to the header information. You can have a look at http://www.python.org/dev/peps/pep-0307. What you are refering to is the so called "extension registry". To this point I haven't heard of any usage of the extension registry mechanism, even though it was specifically created for Zope and Zope as a framework has the largest block of reserved numbers in the registry :) I'd suggest you try this out on some small typical data set and just look at the generated pickles. Hanno _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
