there's no class level GC cycle when dealing with the Session object, no, this bug is local to the ad-hoc subclass mechanism of sessionmaker().
On Jan 11, 2013, at 2:01 AM, Anoop K wrote: > OK. > > So does Session(bind=engine, expire_on_commit=False) usage always guarantee > that engine and all other associated objects are cleared on doing a > session.close() + engine.dispose(). > > > On Friday, 11 January 2013 12:27:16 UTC+5:30, Michael Bayer wrote: > 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 sqlal...@googlegroups.com. >>>> To unsubscribe from this group, send email to >>>> sqlalchemy+...@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 sqlal...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> sqlalchemy+...@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 sqlal...@googlegroups.com. >> To unsubscribe from this group, send email to >> sqlalchemy+...@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 view this discussion on the web visit > https://groups.google.com/d/msg/sqlalchemy/-/fAGeeGQfeRgJ. > 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.
