On Mac OS X v10.4, there are only two settings to control the way in which data in a SQLite-based store is written to disk. In order to provide finer granularity of control over the tradeoff between performance and reliability, on Mac OS X v10.5 Core Data uses two independent pragmas to control these options.
Note that the default fsync behavior on Tiger was fcntl(F_FULLFSYNC) but on Leopard it is now a standard fsync . (
This affects all SQLite databases on Leopard, not just Core Data.) The pragma allows you to toggle this value. See “Configuring a SQLite Store’s Save Behavior” in Persistent Stores for a full discussion.