Storing blobs in external location using built-in CoreData option

Question

I have managed objects that have image properties. Since storing large blobs in CoreData is a bad idea, I'm trying to use the built-in CoreData option "Store in External Record File" which you can see in the Data Model Inspector.

Despite enabling this option, I do not see any image data being stored externally. Judging by the size, it seems like they are still being saved in the sqlite file. What is the issue?

Answer 1

If your store type is NSSQLiteStoreType, your attribute is NSBinaryDataAttributeType. You have enabled setAllowsExternalBinaryDataStorage and your object data size is larger then approximately 1MB.

• Objects that are smaller than 1MB are stored in the sqlite database.
• Objects that are larger are just a reference to a external file.

You'll find the (external) files in a hidden sub-directory at the same location as the persistent store.

<path>/<database>.sqlite
<path>/<your_database>_SUPPORT/_EXTERNAL_DATA/