Materialization

 

When running Classic Query Engine (CQE), a partitioned table is materialized under some conditions.

These conditions are:

• It is a part of a join query.

• It has a GROUP BY clause.

• It has a column built-in function.

In order to reduce the size of the temporary table and reduce the run time involved for the query, any selection in the query that can be used during the creation of the temporary table to eliminate rows is processed to decrease the size of the temporary table and reduce processing time during materialization cases.

When the partitioned table is materialized, the size of the temporary table cannot exceed 4 294 967 288 rows. Pushdown of selection processing is performed to limit the number of rows in the temporary table. If the number of rows exceeds 4 294 967 288, a resource limit error is issued and the query ends.

 

Parent topic:

Queries using Classic Query Engine