Thank you for the explanation, with ROLLBACK / pool_reset_on_return I understand it now.
With this snippet: import time from sqlalchemy import create_engine e = create_engine("postgresql://postgres:sandbox@104.154.217.229/postgres") def go(): now = time.time() with e.connect() as conn: for i in range(100): conn.execute("select 1").fetchall() total = time.time() - now print("completed in %f sec" % (total, )) def go2(): now = time.time() for i in range(100): with e.connect() as conn: conn.execute("select 1").fetchall() total = time.time() - now print("completed in %f sec" % (total, )) go() go2() e = create_engine("postgresql://postgres:sandbox@104.154.217.229/postgres", pool_reset_on_return=None) go2() I get values 17, 44, 17 in remote connection, or 0.10, 0.17, 0.10 within the same datacenter. Zsolt On Fri, 18 Jan 2019 at 23:01, Zsolt Ero <zsolt....@gmail.com> wrote: > > But why is it doing any kind of network activity on a .connect(), if > the previous connection was closed in the pool? > > OK, I created a sandbox server, it'll probably be quicker for you as > the server is in US, but this also did 18 sec for me. > > import time > from sqlalchemy import create_engine > > e = create_engine("postgresql://postgres:sandbox@104.154.217.229/postgres") > > def go(): > now = time.time() > with e.connect() as conn: > for i in range(100): > conn.execute("select 1").fetchall() > total = time.time() - now > print("completed in %f sec" % (total, )) > > go() > > On Fri, 18 Jan 2019 at 22:54, Mike Bayer <mike...@zzzcomputing.com> wrote: > > > > On Fri, Jan 18, 2019 at 4:49 PM Zsolt Ero <zsolt....@gmail.com> wrote: > > > > > > I know I'm far away from a remote server, as the server is a Google > > > Cloud SQL instance, and I'm in a residential cable connection. But > > > ping times are only 145 ms, nothing extreme I'd say. If you'd like I > > > can quickly setup a sandbox instance on GCP for trying this out. > > > > > > Still, I don't even understand the theory, shouldn't connection pools > > > be the same speed as keeping one connection? > > > > the problem you are illustrating has nothing to do with the connection pool. > > > > > > > > -- > > > 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 post to this group, send email to sqlalchemy@googlegroups.com. > > > Visit this group at https://groups.google.com/group/sqlalchemy. > > > For more options, visit https://groups.google.com/d/optout. > > > > -- > > 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 a topic in the > > Google Groups "sqlalchemy" group. > > To unsubscribe from this topic, visit > > https://groups.google.com/d/topic/sqlalchemy/GEhwdHSBVbs/unsubscribe. > > To unsubscribe from this group and all its topics, send an email to > > sqlalchemy+unsubscr...@googlegroups.com. > > To post to this group, send email to sqlalchemy@googlegroups.com. > > Visit this group at https://groups.google.com/group/sqlalchemy. > > For more options, visit https://groups.google.com/d/optout. -- 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 post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.