dbo.AllDocStreams occupied about 135GB while SPD said it is 40GB only

Question

We have a site collection (on farm sp2010 enterprise) with database about 140GB. Checked the table size and found dbo.AllDocStreams occupied about 135GB. By open the SharePoint designer 2010, the size is just 40GB. Checked storage metric also tell me it is 40GB.

What could be the reason of AllDocStreams large size and how can I shrink it? (I have tried shrink the DB using SQL management studio but only very less space released)

Answer 1

Sorry for my stupidity.

Actually there is over 80GB data in recycle bin. Storage metric, SharePoint designer, and powershell $site.usage.Storage all do not count this part of data.

Answer 2

There was an error in SharePoint 2010 storage metrics, related to versioning.

KB2687339 should have fixed this:

When the versioning feature is enabled for a document library in SharePoint Foundation 2010, the Storage Metrics page displays the total size of the document incorrectly.

Answer 3

dbo.AllDocStreams-table includes the contents of the files from your web application using the database (WSS_Content(_GUID)). This includes the version history of the files. Closely related is the dbo.AllDocs-table which includes the other properties of the files (e.g. ID, title).

To decrease the size of dbo.AllDocStreams, your best shot is to simply delete either the file history of the (large) files from your site collection(/web application) or the files in total.

Before deleting any files, check if you are not already running August 2012 CU for SharePoint 2010. This cumulative update fixes the following issue:

After you delete a SharePoint site that contains files that were edited many times, version histories of the files are not deleted from the database.

Edit: There's a suggestion that by installing the update, the issue will be fixed only for the future occasions, so don't except to see a DB size decreasing by installing this update.