The best practice is to avoid using the UPDATE statement on a queue table because the operation requires a full table scan to rebuild the internal queue table cache. You should reserve this statement for exception handling.
An UPDATE statement cannot be in a multistatement request that contains a SELECT and CONSUME request for the same queue table.
For more information on queue tables and the queue table cache, see Teradata Vantage™ - SQL Data Definition Language Detailed Topics , B035-1184 .