On Tue, Feb 12, 2013 at 11:29 AM, shaung <shaun.g...@gmail.com> wrote: > On Tuesday, February 12, 2013 7:18:37 PM UTC+9, Simon King wrote: >> >> If you add echo='debug' to your create_engine call, SA will log all >> calls to the database and rows returned, which might give you an idea >> of where all the time is being spent. >> > > Thanks, Simon. I've looked through the debug log and found the reason. > > It turns out that the table has several foreign key constraints, > and SA is inspecting all of the related tables and all the related tables to > the related tables... > There were 23 tables involved, which explained the long execution time. > > So is there anything I can do about this? > I'm considering two possibilities: > > 1. Ignore the constraints to speed up > 2. Or cache all the meta data to a disk file so no need to wait when > restarting the program > > Either would be fine for me. > Is it possible? >
Caching the metadata should be fairly easy if you are happy with that approach. I think MetaData instances are picklable: http://stackoverflow.com/questions/11785457/sqlalchemy-autoloaded-orm-persistence Simon -- 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 http://groups.google.com/group/sqlalchemy?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
