[ZODB-Dev] RelStorage Blobs and packing

[Shane Hathaway]

On 10/15/2010 10:47 AM, Jim Fulton wrote:
> On Fri, Oct 15, 2010 at 12:34 PM, McCuaig, Scott (MGS)
>> We plan to introduce plone.app.blob very shortly. However, we charge a small
>> fee to the clusters which we divide amongst them based on how much space
>> they're using and I'm having trouble understanding exactly how the
>> blobstorage disk usage is affected by packing. I added a few File objects to
>> a site and saw the blobstorage disk usage grow (using the du shell command),
>> but after deleting the objects and packing the database, the size didn't
>> decrease. I thought that maybe the space was freed up to Zope — while still
>> appearing used to the OS — but the space continued to increase (according to
>> du) when I added another file.
>>
>> I've already recommended rethinking the pricing model, but we still have to
>> figure out how to shrink the blobstorage. I feel like I'm missing something
>> fundamental, but maybe I'm just doing something stupid. Surely, there must
>> be an easy answer!
>
> To be clear, this is a question about how RelStorage handles blobs.

True, although the current implementation mostly matches FileStorage.

Scott, did you set up a blob directory?  If so, the files you uploaded 
should have landed in the blob directory.  When you removed the files 
and packed, they should have been removed from the blob directory. 
Please confirm that is happening as it should.

If you did not set up a blob directory, then the files must have ended 
up in the database somehow.  Oracle may require some kind of maintenance 
in order to reclaim that space.

Shane