public List<HiveRelOptMaterialization> getRewritingMaterializedViews(ASTNode ast) {
    return materializedViewsCache.get(ast);
  }
Returns the materialized views in the cache for the given database.

@return the collection of materialized views, or the empty collection if none
ql/src/java/org/apache/hadoop/hive/ql/metadata/HiveMaterializedViewsRegistry.java