iX V6.5 (30391-90011)

508 Chapter11

B-Tree Indices

External Commands and Utilities Affected

DBPUT, DBDELETE, and DBUPDATE

DBPUT and DBDELETE trigger similar operation to the associated B-Tree index ﬁle for all

adds or deletes to or from a master data set. DBUPDATE to a master is not allowed even

when critical item update is on.

Adding a record to the B-Tree index ﬁle is done with an FWRITE call. The KSAM ﬁles do not

have the DUP option, so KSAM will reject FWRITEs that attempt to add a duplicate key

value. The KSAM ﬁles are built with the REUSE option, which means that the space

occupied by deleted records will eventually be reused.