Control interval (CI) access is a read option that causes the VSAM access method to use direct control interval reads to retrieve data records.
If you extract all data from the VSAM data set, this option might improve sequential read performance. If you specify a WHERE clause when retrieving the data, CI access provides no performance benefit.
To select CI access at the data map level, select the CI ACCESS option on the
Access Method
tab in the
Data Map Properties
dialog box. The
CI ACCESS
option is valid for KSDS, ESDS, and RRDS access methods.
CI access is not supported for compressed VSAM data sets or VSAM data sets with spanned records.