1. Yeah, I do have index on app_key and device_token 2. I realized the issue with how I use sessions every request, so , later, instead of sessions, I directly call engine.execute where engine is initiated just once from another file.
Seems no improvement compared to session... 在 2014年3月13日星期四UTC+8下午11时33分31秒，Jonathan Vanasco写道： > > in the database, is there an index on `app_key` ? I'd imagine selects are > going to be slow on a sequential scan. > > If there is a "unique" constraint on the app_key or it's a primary key, > that's going to be a performance hit too. > > Personally, I've found digest/hash style keys to have terrible > performance. I would probably have the table like this: > > id = primary key + serial/auto-increment > app_key = unique index > > i'd grab the app_key at the start of the web-request and note the object > id. then i'd do updates using the object id. > > the database should optimize locating the record by app_key using the > index field; and they tend to be faster finding records with an integer key > than strings (for your updates) > > Other than that, this looks to me like an anti-patten. You're not > opening/closing new Sessions for every request, but for every Database > operation. > > Your "session" should ideally start at the beginning of the http web > request, and end when you're ready to commit/close. > > Your design will not scale. SqlAlchemy doesn't have much overhead, but > you've designed your application in a way that you get hit by virtually all > the overhead multiple times on every action. That's your biggest problem. > > Honestly, I think your best way to improve performance would probably be > to toss this module, and start from scratch. the various python web > frameworks integrate sqlalchemy differently, but most have recommended > practices. I'd start with that. > -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
