The VSAM KSDS interface module DTLAMLGF uses point() and read() keyed access if the access supports the values supplied in the WHERE clause for the primary key column. Otherwise the VSAM KSDS interface module uses non-optimized read() calls across the entire file to retrieve records.
For DISAM files on Windows or Linux, while you can define keys that include integer values, PowerExchange cannot perform optimized reading on those keys if they inlcude LE, LT, GE, or GT conditions.