The first time that you configure a cache size, use auto cache mode. After you run the mapping, analyze transformation statistics in the mapping log to determine the cache sizes required to run the transformations in memory. When you configure the cache size to use the value specified in the mapping log, you can ensure that no allocated memory is wasted. However, the optimal cache size varies based on the size of the source data. Review the mapping logs after subsequent mapping runs to monitor changes to the cache size. If you configure a specific cache size for a reusable transformation, verify that the cache size is optimal for each use of the transformation in a mapping.

To define specific cache sizes, configure the cache size values in the transformation properties in the Developer tool.