Hi, Recently we've been looking into the baked query feature as a method of speeding up query compilation. We also use a before_execute hook to modify the query before execution to handle permission related stuff. One thing that turned up was that when using a baked query that it cached the final string version.
What this means is that the baked query framework caches the results of the before_execute hook meaning that queries occasionally produce the wrong output in situations where the before_execute hook would do something different. I'm not clear if this is a bug or a "you break it you get to keep both pieces". We worked around this (yes, before_execute hooks are evil) but this became more urgent when an old product accidentally got SQLAlchemy 1.2.0b where baked queries are used for lazy loading, which caused all sorts of funky errors. Whoops! I'm wondering if there is a way of at least detecting this? Such that if a before_execute hook changes a query that the result is automatically not cached. That would at least prevent things from breaking unexpectedly. But long term, caching the compilation is really nice and so we'd like to be able to keep that feature. Our hook is predictable such that with the same input query and a parameters which is stored in the Query object you always get the same result. So it would in theory be possible to work with the baked query framework, but I'm totally not clear how that would work. Any ideas? As an aside, we worked around a few things by creating a WrappedBakedQuery class, which allowed us to do thing like: baked_query += lambda q: q.filter(Table.col == bind_param('foo')) baked_query.set_param('foo', 1) Which worked better in our setup. Have a nice day, -- Maritjn -- 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.