Hey, Michael Bayer wrote: > On Jun 17, 10:04 am, Martijn Faassen <[EMAIL PROTECTED]> wrote: >> Hi there, >> >> A question came up when thinking about how to integrate SQLAlchemy with >> Zope. >> >> Is it all right to recreate an engine, once per session scope (thread, >> say), or is it better to reuse the same engine as much as possible? How >> expensive is engine creation? Do you miss features like, say, connection >> pooling, if you recreate an engine? >> > > you should reuse a single engine. It contains a pool of connections, > so recreating engines means new connections are constantly rebuilt and > it defeats the purpose of the pool. Other than that the creation of > an engine is not very expensive but even a small expense is needless > here.
Okay, understood, thanks for the answer! > I can't think of any advantage to recreating engines on each request > (except if you're concerned about no-longer-used applications keeping > their engines around....in which case I'd use a WeakValueDict). We wouldn't recreate the engine on each request, just each time a session is constructed for a new thread (or actually new application/thread combination). (that is, ScopedSession would get a session_factory that did this). The reason I'm checking is because it might simplify some initialization code if we could just re-create the engine in case a new thread kicks in. We'll figure out how to retain a single engine though. Regards, Martijn --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
