Re: Core Data troubles - not removing objects

FROM : Benjámin Salánki
DATE : Sun Nov 04 17:37:22 2007

On Nov 3, 2007, at 11:58 PM, Ben Trumbull wrote:

>> My problem is, that if I include a huge amount of data like an
>> uncompressed image that will swell the SQLite file to 72MB,

>
> Generally, large media files should be stored externally to the 
> database, and a URI and metadata for it stored in a database record.


I know, I was just testing to see if larger amounts of data would make 
any difference.

>
>

>> removing the item does not reduce the file size. I found that if I 
>> add another
>> item later that should be around the same size the file size does not
>> change so what you wrote makes sense in that the "holes" inside the
>> file are filled up with new data but I can't get the file size to
>> reduce even by a few bytes.

>
> What you're seeing is internal fragmentation.
>

>> I was thinking of maybe implementing a "consolidate database" 
>> function
>> that would load the data from the file to memory, remove the file and
>> recreate the items which would reduce the file size if I am correct.

>
> That's very expensive.
>

>> Or does anyone have a better solution?

>
> Yes.  You can manually vacuum an SQLite database with:
>
> sqlite3 filename "vacuum"
>


Very nice, this should do the trick. Thanks for the help!

ben

> Programmatically, you can use an NSTask.
>
> - Ben
>