|Under the section "Altering a Table Space", the following new sections |are to be added:
|You can add a container to an SMS table space on a partition (or node) |that currently has no containers.
|The contents of the table space are rebalanced across all containers. Access |to the table space is not restricted during the rebalancing. If you need |to add more than one container, you should add them all at the same time.
|To add a container to an SMS table space using the command line, enter |the following:
| ALTER TABLESPACE <name> | ADD ('<path>') | ON NODE (<partition_number>)
|The partition specified by number, and every partition (or node) in the |range of partitions, must exist in the nodegroup on which the table space |is defined. A partition_number may only appear explicitly or within a range |in exactly one on-nodes-clause for the statement.
|The following example shows how to add a new container to partition number |3 of the nodegroup used by table space "plans" on a UNIX based operating |system:
| ALTER TABLESPACE plans | ADD ('/dev/rhdisk0') | ON NODE (3)
|Following the section titled "Changing Table Attributes," |add the following sections:
|Modify the attributes of an existing identity column with the ALTER TABLE |statement. For more information on this statement, including its syntax, refer |to the SQL Reference.
|There are several ways to modify an identity column so that it has some |of the characteristics of sequences.
|There are some tasks that are unique to the ALTER TABLE and the identity |column: |
|Modify the attributes of an existing sequence with the ALTER SEQUENCE statement. |For more information on this statement, including its syntax, refer to the SQL Reference.
|The attributes of the sequence that can be modified include: |
|There are two tasks that are not found as part of the creation of the sequence. |They are: |
|After restarting a sequence or changing to CYCLE, it is possible to generate |duplicate sequence numbers. Only future sequence numbers are affected by the |ALTER SEQUENCE statement.
|The data type of a sequence cannot be changed. Instead, you must drop the |current sequence and then create a new sequence specifying the new data type.
|All cached sequence values not used by DB2 are lost when a sequence is |altered.
|To delete a sequence, use the DROP statement. For more information on this |statement, including its syntax, refer to the SQL Reference.
|A specific sequence can be dropped by using:
| DROP SEQUENCE sequence_name
|where the sequence_name is the name of the sequence to be dropped |and includes the implicit or explicit schema name to exactly identify an |existing sequence.
|Sequences that are system-created for IDENTITY columns cannot be dropped |using the DROP SEQUENCE statement.
|Once a sequence is dropped, all privileges on the sequence are also dropped.
|The SWITCH ONLINE clause of the ALTER TABLESPACE statement can be used |to move table spaces in an OFFLINE state to an ONLINE state if the containers |associated with that table space have become accessible. The table space is |moved to an ONLINE state while the rest of the database is still up and being |used.
|An alternative to the use of this clause is to disconnect all applications |from the database and then to have the applications connect to the database |again. This moves the table space from an OFFLINE state to an ONLINE state.
|To switch the table space to an ONLINE state using the command line, enter:
| ALTER TABLESPACE <name> | SWITCH ONLINE
|DMS tables spaces are now created and resized in parallel, which offers |a performance benefit. The degree of parallelism is equal to the number of |prefetchers plus 1.