Storing large amounts of text in Core Data

I'm trying to see what the best way to store large amounts of text (more than 255 characters) in Cocoa would be. Being a big fan of Core Data, I would assume there's an effective way to do so. However, I feel like 'string' is the wrong da开发者_运维问答ta type for this type of thing. Does anyone have any info on this? I don't see an option for BLOB in Core Data

Well you can't very well compress the text or store it as a binary that must be translated, otherwise you give up SQLite's querying speed (because all text-stored-as-binary-encoded-data) records must be read into memory, translated/decompressed, then searched). Otherwise, you'd have to mirror (and maintain) the text-only representation in your Core Data store alongside the more full-featured stuff.

How about a hybrid solution? Core Data stores all but the actual text; the text itself is archived a one-file-per-entry-in-Core-Data on the file system. Each file named for its unique identifier in the Core Data store. This way a search could do two things (in the background, of course): search the Core Data store for things like titles, dates, etc; search the files (maybe even with Spotlight) for content search. If there's a file search match, its file name is used to find the matching record in Core Data for display in your app's UI.

This lets you leverage your app-specific internal search criteria and Spotlight's programmatic asynchronous search. It's a little more work, granted, but if you're talking about a LOT of text, I can't think of a better way.

The BLOB data type is called "Binary data" in Core Data. As middaparka has pointed out, the Core Data Programming Guide offers some guidance on how to deal with binary data in Core Data. Depending on your requirements, an alternative to using BLOBs would be to just store references to files on disk.

I'd recommend a read of Apple's Core Data Programming Guide (specifically the "Core Data Performance" section). This specifically mentions BLOBs (see the "Large Data Objects (BLOBs)" section) and gives some, albeit vague, guidelines.