oncheck -pB: Display blobspace statistics
The -pB option displays statistics that describe the average fullness of blobspace blobpages in a specified table. These statistics provide a measure of storage efficiency for individual simple large objects in a database or table. If you do not specify a table or fragment, the option displays statistics for the entire database. For more information, see optimizing blobspace blobpage size in the chapter on managing disk space in the Informix® Administrator's Guide.