SQL/MX 2.x Installation and Management Guide (H06.04+)

Reorganizing SQL/MX Tables and Maintaining Data
HP NonStop SQL/MX Installation and Management Guide—540436-001
10-5
DDL Lock Considerations for MODIFY, import,
POPULATE INDEX, DUP, and PURGEDATA
When you want to restart the reorganization of the table, reissue the FUP RELOAD
command. In this case, you must omit the NEW option so that FUP restarts a
previously suspended reload operation.
If you want to change the RATE or SLACK option, you can do so in the restart
command. This command restarts the FUP RELOAD operation for the table
CUSTOMER, but adjusts the reloading rate to 20 percent:
FUP
- RELOAD $DATA08.ZSDAWVHH.J8MGRZ00, RATE 20, SLACK 50
If you want to keep the same RATE and SLACK values when you restart the
reorganization process, enter the FUP RELOAD command without the RATE and
SLACK parameters:
FUP
- RELOAD $DATA08.ZSDAWVHH.J8MGRZ00
After a FUP RELOAD operation has been suspended and you want to start this
operation completely over again, enter the FUP RELOAD command with the NEW
option:
FUP
- RELOAD $DATA08.ZSDAWVHH.J8MGRZ00, NEW, RATE 30, SLACK 50
In the FUP RELOAD command, the NEW option is necessary only when restarting a
RELOAD operation over again from the beginning, following a RELOAD suspension.
DDL Lock Considerations for MODIFY, import,
POPULATE INDEX, DUP, and PURGEDATA
A utility operation usually occurs over several TMF transactions, time during which
other operations might attempt to run. However, operations that change metadata and
label information for the same table or index, including DDL requests and other utility
operations, are considered structure changing operations. To prevent other structure
changing operations from running before it completes, a running utility obtains and
holds a DDL lock for the duration of its execution.
The DDL lock persists across the boundaries of the TMF transactions that compose
the utility operation. The DDL lock signifies that a structure change is in progress for a
given table or one of its indexes. Other structure changing operations cannot be
performed until the operation that holds the DDL lock completes. DDL locks are usually
obtained for utilities that run in multiple operations and therefore require compensating
work to recover the utility operations.
The utility request informs NonStop SQL/MX that it is running, performs commands
over as many TMF transactions as necessary, then informs NonStop SQL/MX that the
operation has completed.
Structure changing operations include: