On Mon, May 17, 2021, at 6:22 PM, Anupama Goparaju wrote: > Thanks for the quick reply. Correct, using the same recipe of cx_Oracle > SessionPool + SQLAlchemy NullPool. > If we handle the connection close explicitly to release to the pool, will > that skip any exception handling on connections that Session object handles > internally for db connections and also any rollbacks on errors?
I dont see any error handling that would be skipped, connection-level error handling is all within the connection itself. a rollback() is separate from the scope of the connection and the Session will begin/commit/rollback on that connection. > On Monday, May 17, 2021 at 3:08:34 PM UTC-6 Mike Bayer wrote: >> >> >> On Mon, May 17, 2021, at 4:21 PM, Anupama Goparaju wrote: >>> Hi, >>> >>> I see in the documentation >>> <https://docs.sqlalchemy.org/en/13/orm/session_basics.html> that we can >>> bind a connection to a SQLAlchemy session object: >>> >>> *# at the module level, the global sessionmaker,* *# bound to a specific >>> Engine* >>> Session = sessionmaker(bind=engine) >>> >>> *#** later, some unit of code wants to create a* *# Session that is bound >>> to a specific Connection* conn = engine.connect() >>> session = Session(bind=conn) >>> >>> How do we release the connection to an external connection pool safely? For >>> instance, if we are using a cx_Oracle SessionPool >>> <https://cx-oracle.readthedocs.io/en/latest/api_manual/session_pool.html> >>> to acquire and release connections? >>> session.close() is not doing that seamlessly in this case. >>> >>> if we do, session = Session(bind=engine) - it usually releases connection >>> to the pool seamlessly on session.close(). >> >> if you acquire a connection using engine.connect(), you must release it to >> the connection pool using connection.close(). this is independent of the >> Session being bound to this Connection while it is acquired from the pool. >> Session.close() will not achieve this when you are using >> Session(bind=connection) as the Session understands the scope of this >> Connection is external to that Session. >> >> This is then a separate issue from the use of cx_Oracle's SessionPool, for >> which we would assume you are using the recipe at >> https://docs.sqlalchemy.org/en/14/dialects/oracle.html#using-cx-oracle-sessionpool >> . >> >> >>> >>> Thanks, >>> Anupama >>> >>> >>> >>> -- >>> SQLAlchemy - >>> The Python SQL Toolkit and Object Relational Mapper >>> >>> http://www.sqlalchemy.org/ >>> >>> To post example code, please provide an MCVE: Minimal, Complete, and >>> Verifiable Example. See http://stackoverflow.com/help/mcve for a full >>> description. >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "sqlalchemy" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to sqlalchemy+...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sqlalchemy/66a43491-e94b-4b9c-a2ff-6e4ec8ee2cccn%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/sqlalchemy/66a43491-e94b-4b9c-a2ff-6e4ec8ee2cccn%40googlegroups.com?utm_medium=email&utm_source=footer>. >> > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sqlalchemy/a47048cd-178b-4191-bc42-23abeede0d69n%40googlegroups.com > > <https://groups.google.com/d/msgid/sqlalchemy/a47048cd-178b-4191-bc42-23abeede0d69n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/c59343db-978c-4929-8bc7-4623ef4b96fe%40www.fastmail.com.
