As the table is updated, queries that define the join indexes are re processed to obtain the records for updating the join indexes, wherein one or more common joins are identified among the join indexes, each common join is materialized only once in a common spool file, and {HEAD ~ the common spool file} is used to materialize {TAIL ~ one or more rows} for updating the join indexes 
As the table is updated , queries that define the join indexes are re processed to obtain the records for updating the join indexes , wherein one or more common joins are identified among the join indexes , each common join is materialized only once in a common spool file , and { HEAD ~ the common spool file } is used to materialize { TAIL ~ one or more rows } for updating the join indexes
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH