Full Text Search w/ Core Data

This page pulls together a series of articles I wrote about implementing Full-Text Search (FTS) on the iPhone using Core Data. This is a fairly specific problem; if you’re not using Core Data, and instead just using SQLite on the iPhone, your best bet is probably to compile your own build of SQLite into your app, and include the FTS3 extension. (The default build on the iPhone, at the time of writing, doesn’t include it.)

On the other hand, if you are using Core Data, it looks like you must roll your own FTS implementation. Core Data (reportedly) doesn’t play well with non-default SQLite builds, and it’s not easy/recommended to directly access the data store underneath the Core Data interface anyway. In the mysterious future AAPL may decide to expose FTS functionality in Core Data, but until then, I think you’ll have to do something along the lines of what I cover here.

Source Code

Here is the latest source code for the project:

• fts.zip

Please consider it licensed under 2-clause BSD; check the LICENSE.txt file for details.

Posts

• Prototyping in Python
• Key parts of a rough Core Data FTS implementation
• Performance: Complex queries may yield suboptimal query plans
• Performance: Avoid sorting long text fields
• Bug Fix: Indexing
• Implementing “AND” style queries
• Performance: Avoid the BEGINSWITH predicate operator
• Demo