whar is CI SPLIT OR CA SPLIT give me a example.
Posted: Tue Oct 21, 2008 6:37 pm
whar is CI SPLIT OR CA SPLIT give me a example.I am new in mainframe.thanks.
CI and CA splits occur as a result of data record insertions. If a record is to be inserted and there is not enough free space in the CI, the CI will be split.
Approximately half of the records in the CI are transferred to a free CI and the record to be inserted is placed in the original CI.
If there are no free CIs and a record is to be inserted, a CA split occurs.
The physical sequence of records and CIs is no longer the same as the logical sequence after a split. A new index entry is inserted in the sequence set for the new CI, and the existing index entry is updated.
CI and CA splits can therefore cause performance degradation as records are no longer held in the easiest accessible sequence.
Refer to IBM Redbook - "VSAM demystified" - SG24-6105-00 - which can be found at www.ibm.com/redbooks