the event mechanics issue applies to 0.7 and 0.8. while the engine will be gc'ed in 0.8, the sessionmaker itself, if used, will still create an anonymous subclass that is not cleared. creating many ad-hoc sessionmaker() objects, while this was not its intended use, will cause memory to grow.
the patch at http://www.sqlalchemy.org/trac/attachment/ticket/2650/2650.patch resolves. On Jan 11, 2013, at 1:29 AM, Michael Bayer wrote: > the sessionmaker() object is not GC-able in 0.7 right now due to event > mechanics. This issue does not exist in 0.8. I'll add a note. > > > > On Jan 11, 2013, at 1:18 AM, Michael Bayer wrote: > >> there's some side effect occurring as a result of how 0.7 creates a new >> subclass when using sessionmaker. Since you don't need a sessionmaker here, >> please use this form: >> >> return Session(bind=engine, expire_on_commit=False) >> >> or upgrade to 0.8.0b2. >> >> >> >> On Jan 11, 2013, at 1:08 AM, Anoop K wrote: >> >>> I tried the code in my setup.(SQLAlchemy-0.7.8-py2.6). Looks like engine >>> did not got GCed. >>> >>> [anoop@localhost tmp]$ p engtest.py >>> about to delete sn... >>> about to gc.collect()... >>> Traceback (most recent call last): >>> File "engtest.py", line 31, in <module> >>> assert engine_is_removed >>> AssertionError >>> >>> >>> >>> On Thursday, 10 January 2013 18:55:59 UTC+5:30, Anoop K wrote: >>> It seems engine created using create_engine is not freed after cleanup of a >>> session. Object graph indicates that event.listen for pool is holding >>> reference to engine even after session is garbage collected. >>> What is the right way/api to delete an engine ? >>> >>> UseCase >>> As there are lot of databases in multiple boxes whose ip/user/password can >>> change I would like to destroy session and engine after use. Cost of >>> creating/closing connection can be ignored for my use case. >>> >>> >>> >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "sqlalchemy" group. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msg/sqlalchemy/-/RWBNo1sT1ogJ. >>> To post to this group, send email to sqlalchemy@googlegroups.com. >>> To unsubscribe from this group, send email to >>> sqlalchemy+unsubscr...@googlegroups.com. >>> For more options, visit this group at >>> http://groups.google.com/group/sqlalchemy?hl=en. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sqlalchemy" group. >> To post to this group, send email to sqlalchemy@googlegroups.com. >> To unsubscribe from this group, send email to >> sqlalchemy+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/sqlalchemy?hl=en. > > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To post to this group, send email to sqlalchemy@googlegroups.com. > To unsubscribe from this group, send email to > sqlalchemy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sqlalchemy?hl=en. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
