Federated Search
Federated Search takes a user's query and distributes it to multiple engines, then combines the results back together. This approach is sometimes preferred as it doesn't require any single engine to index all of the content.
Key federated search requirements in the enterprise:
- flexibility in combining results
- maintaining & mapping security credentials
- advanced duplicate detection and removal
- combining results-list and page navigators
- translating into different search syntaxes