Hoi Mike, You're right, we should probably measure it first. You state that the simple joins and filters are probably cheap which I don't doubt. We also do correlated subqueries and stuff. Actually, we also use the baking mechanism to cache some of our own processing which goes into the construction of the query.
However, if the QueryContext is the important part then it may not matter. We'll time it and see what happens. My question was mostly whether the "spoil but not spoil" approach might be a quickwin. Have a nice day, Martijn On Wed, 14 Nov 2018 at 14:54, Mike Bayer <mike...@zzzcomputing.com> wrote: > > The two things that the BakedQuery caches are the QueryContext, which > is the thing that Query creates when everything it needs is ready to > go and is by far the most expensive part of the Query, and then > indirectly it caches the string SQL which also cannot be generated > until everything is ready to go. That is, there's not much to cache > before you're ready to generate the SQL. If you're looking to just > cache the overhead of calling the join() or filter() method, that is > something, but this would need some new mechanism of having that be > cached as well within the bakery, e.g. a Query by itself that's the > result of some series of steps. It might be something you'd want > to play with if you really want to hack on the internals of the > BakedQuery but I'd recommend doing some code profiling up front to see > potentially how much savings you'd really get, because I'm not sure > it's that much. If you have a limited number of Ns, then it's > probably not worth it. > > > > -- Martijn van Oosterhout <klep...@gmail.com> http://svana.org/kleptog/ -- 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.
