You can configure multiple Lookup transformations in a mapping to share a single lookup cache. The Integration Service builds the cache when it processes the first Lookup transformation. It uses the same cache to perform lookups for subsequent Lookup transformations that share the cache.
You can share caches that are unnamed and named:
When Lookup transformations in a mapping have compatible caching structures, the Integration Service shares the cache by default. You can only share static unnamed caches.
Use a persistent named cache when you want to share a cache file across mappings or share a dynamic and a static cache. The caching structures must match or be compatible with a named cache. You can share static and dynamic named caches.
When the Integration Service shares a lookup cache, it writes a message in the session log.