Question

I grab data from the web and then I save that in coredata. Not all data must be created new. If the data is the same with previously stored data, then we use old data.

To speed up the saving process, I prefetched old data.

Turns out it’s still slow. The saving process is still slow.

I suspected that core data makes IO trips again after the prefetch.

How do we know whether it does again? Can we break on “IO” trip or something?

Answer 1

To monitor Core Data/SQLite activity, you can

• Goto “Edit Scheme …” and add “-com.apple.CoreData.SQLDebug 1” to the “Arguments Passed on Launch”. Then you will get console output for all SQLite actions.
• Profile your app with Instruments and the “Core Data” tool.