Where is the file size stored in the eB database?

Where is the file size stored in the eB database?

I have created a report that lists the file size.

START WITH File
SELECT 
   Id,
   FileSize,
   Name 
WHERE 
    Document.Class.Code = @DocClass 

Because I am trying to determine the file size of all of 600,000 files for a doc class I am unable to run the report and get a complete list.  I am looking for a db query to run to determine this information but I can't find the correct field and table.

I thought it might be in DOC_SOURCE which has the fields ORIG_FILE_NAME AND DOC_SIZE BUT DOC SIZE IS BLANK. 

Can someone point me in the correct direction?  Thanks for your help.