Stalled queries in the Pivotal HDB engine

Queries might become stalled in the Pivotal HDB engine because of a defect in the Pivotal optimizer.

To resolve the problem, the Pivotal administrator can change the server defaults, or add the following command block for the connection in IBM Cognos Administration.

<commandBlock>
  <commands>
   <sqlCommand>
    <sql>select disable_xform('CXformExpandNAryJoinDP')</sql>
   </sqlCommand>
  </commands>
</commandBlock>

If a table was created in HDB with partitioning, the Pivotal JDBC driver returns metadata for each partition of the table. Currently, there is no means in the Pivotal software to prevent it from returning the extra metadata. A modeler in IBM® Cognos® Analytics does not need to include that additional metadata for queries to work.