how can we delete the cache files while we using aggregator transformaation?

After the session executes DTM removes the cache memory and deletes   cachefiles             Incase of persistant cache and incremtal aggregation cache files are     saved.
            Generally cache files are created in Informatica sever no default  memory is allocated for this once memory exceeded than these (index  cache) files You can see this in cache directory.

 cache are automatically deleted by the power ceter server(i.e Data cache and Index cache) after session completes If you use persistent cache power center save that cache for further use