Find size of a table in Netezza

To  find the size of a table in Netezza use the following query which would help in getting the details

       
SELECT b.database,b.schema,b.tablename
,SUM(a.ALLOCATED_BYTES)/POW(1024,3) AS ALLOCATED_GB
,SUM(a.USED_BYTES)/POW(1024,3) AS USED_GB
  FROM SYSTEM.DEFINITION_SCHEMA._V_SYS_OBJECT_STORAGE_SIZE a
  inner join
  _v_table_xdb b
  on a.tblid = b.objid
 group by 1,2,3