Materialize caches an entire relation, including its descendants in the executor’s memory. Iterators over the relation and its descendants can then be reset repeatedly. This is necessary if the relation is duplicated or if the relation is to be aggregated over as well as detailed. Materialize does not change any data. Materialize simply accumulates rows from its input and does not release the rows until they are no longer needed. For more information about controlling how a relation is materialized, see
Configuring BIRT iServer.
