The advantages of sp_spaceused are that:
It provides quick reports without excessive I/O and locking, since it uses only values in the table and index OAM pages to return results.
It shows the amount of space that is reserved for expansion of the object, but not currently used to store data.
It provides detailed reports on the size of indexes and of text and image, and Java off-row column storage.
Use sp_helpartition to report
the number of pages in each partition. sp_helpartition does
not report the same level of detail as sp_spaceused,
but does give a general idea of the amount of space a partition
uses. In Adaptive Server version 15.0.2 and later, sp_spaceusage provides
detailed information about a variety of subjects, including the
space used by tables at the index and partition level, and fragmentation.
See the Adaptive Server Reference Manual: Procedures for more information about all these system procedures.
