Question

I am building a project where I need to prepopulate a coredata database with existing data.

I built a parser to create the sqlite file in the iOS Simulator, everything works fine.
I am using a single entity, and one of the attribute is indexed.
Performance after parsing my data file into core data is great, everything is good.

Now I am using the generated sqlite file (~200Mb) in project with same data model, same index, etc… and on first startup I copy over the db file to prepopulate the data

    NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:@"myproject" ofType:@"sqlite"];
    NSString *storePath = [[[self applicationDocumentsDirectory] path] stringByAppendingPathComponent: @"myproject.sqlite"];

    NSError *error;
    if (![[NSFileManager defaultManager] fileExistsAtPath:storePath]) 
    {
        if ([[NSFileManager defaultManager] copyItemAtPath:defaultStorePath toPath:storePath error:&error])
            NSLog(@"Copied starting data to %@", storePath);
        else 
            NSLog(@"Error copying default DB to %@ (%@)", storePath, error);
    }

The copying works fine, and the data can be accessed normally.
However the performance is terrible, and the index is clearly not being used.
A look at the size of the sqlite file after the copy operation, it went from 200Mb to 120Mb.
Everything looks alright in the model, what needs to be indexed is checked as indexed.

1) Is there a way for the index data not to be removed when copying the sqlite over?
2) Is it possible to programmatically rebuild the index?
3) Any other thoughts?

Answer 1

Looks like the problem was that the project didn’t get cleaned well in between tests, it could have been a bug in Xcode 4.3 I was using at the time.

The same methodology is working fine now.