About this task
The processing of queries against
column-organized tables
require that intraquery parallelism be enabled for the application
that is compiling and executing the query. The following statement
types also require intraquery parallelism:
- All DML operations that reference column-organized tables
- The ALTER TABLE ADD UNIQUE / PRIMARY KEY CONSTRAINT statement
against a column-organized table
if rows were inserted into the table
- The RUNSTATS command against a column-organized table
- The LOAD command against a column-organized table
If an application attempts to run one of these statements or
commands without intraquery parallelism enabled, an error is returned.
Intraquery parallelism uses either intrapartition parallelism, interpartition
parallelism, or both. Interpartition parallelism is not available
because
column-organized tables
are supported in only single-partition environments.
Access
to column-organized tables
also require intrapartition parallelism. Setting DB2_WORKLOAD to ANALYTICS implicitly
enables intrapartition parallelism for workload objects that are created
with MAXIMUM DEGREE set to DEFAULT, and is recommended
when you use column-organized tables.
If this registry variable is not set, or is set to another value,
you must explicitly enable intrapartition parallelism before you access column-organized.