Slow Core Data performance after migration

Question

i've got some strange Core Data issue after performing an lightweight migration - my app for iPad is using a versioned data model, right now i'm migrating to another data model with only one change : adding an attribute to entity. Migration proceeds without any problems, and after process is done I can run app with all data migrated - only problem is that each save request take about 10x more time than before migration.

• i've checked core data logs of migration process - no error listed
• core data logs (sql queries) are the same before and after migration, only much more slower
• i've opened sqlite database in external sqlite viewer - query times from before migration are the same as times after migration.
• i've added NSSQLiteManualVacuumOption for persistent store after migrations, performance of core data gets a little bit better, still much slower that before migration.

Do have any idea what could be going wrong here? How to restore performance from before migration?

Answer 1

Guess I've found the solution. I've replaced automatic lightweight migration with very basic custom migration - with just Xcode generated model mapping - now everything works like a charm. Looks like automatic lightweight migration mechanism cannot handle properly model and data of my persistent store, which is strange because I didn't receive any warning or errors. Thanks for help everyone.