The initial attributes that are defined for a
dynamic cluster table cannot be changed. That is, you cannot modify the number of member slots, the unique
index validation setting, or the DELETE= setting of a dynamic cluster table after
it has been created. However, if the original server tables did not have the MINMAXVARLIST=
attribute defined, you can define this attribute for the cluster table. The MINMAXVARLIST=
attribute identifies table columns for which the server will maintain minimum and
maximum values in the cluster table’s metadata.
An optional MINMAXVARLIST
attribute can be added to the cluster table with the CLUSTER MODIFY
statement. The form of the CLUSTER MODIFY syntax is as follows:
CLUSTER MODIFY cluster-table-name
MINMAXVARLIST=(column-1 column-2 ... column-n);
cluster-table-name
specifies the name of the dynamic cluster table to be modified.
column-n
specifies the name
of a table column.
The columns that you
specify must not already have a definition for the MINMAXVARLIST attribute.
Note: Before you submit the CLUSTER
MODIFY statement, you must take the cluster table offline. The CLUSTER
MODIFY statement requires that you have exclusive access to the table.
When you execute this statement, the server automatically unclusters
the dynamic cluster table, makes the requested column modifications
to the individual member tables, re-creates the cluster table, and
performs a full table scan to initialize the MINMAXVARLIST values
in each member table. You must wait for the process to complete before
making the table available again. The processor time required for
the CLUSTER MODIFY statement is directly related to the sizes of the
member tables in the dynamic cluster table.
If an error occurs while the CLUSTER MODIFY statement is running, the dynamic cluster
table is not re-created. You will need to re-create it by using the CLUSTER CREATE
statement.