If the stream attribute is omitted in EMML statements or it is set to false, results from <directinvoke>, <raql> or <sql> statements are not available to other mashup statements until all results have been received. For example:

The results are also represented in XML, creating a document type variable with a document object model (a DOM) which takes time as well as additional memory. With very large datasets, this can cause the mashup to fail due to inadequate memory or to timeout unnecessarily. The DOM, however, does enable access to the data in EMML statements using XPath rather than RAQL.