[Dieter] >>> Subtransactions used to be used for two purposes: >>> >>> * ensure that newly created objects get "_p_" attributes >>> (especially "_p_jar" and "_p_oid") >>> >>> * release memory in the mid of large transactions >>> (i.e. reading and/or writing large amounts of objects) >>> >>> With ZODB 3.4, subtransactions are implemented as savepoints. They can >>> still be used for the first purpose. But, they no longer start cache >>> garbage collection. >>
[Tim] >> Jim, was the latter intentional? It surprised me when Dieter pointed it >> out, and in the ZODB NEWS file I explicitly implied <wink> otherwise. [Jim] > Later what? Dieter made two claims; "the latter" claim is the second claim, i.e., about cache gc. > Assuming that we no longer call incrgc, that would be an oversight. > When a connection does a savepoint, it should also do an incrgc. OK, that's what I figured the intent was. It's not being done now; I'll fix it. > Note that applications that *really* want to reduce memory after a > savepoint may and often should make explicit cache-management calls on > the transaction. This should still work. I tried it -- it does work ;-). Making a savepoint alone currently does not trigger any cache gc. _______________________________________________ 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
