DB2 Version 10.1 for Linux, UNIX, and Windows

Compatibility of online backup and other utilities

Some utilities can be run at the same time as an online backup, but others cannot.

The following utilities are compatible with online backup:

EXPORT
INSPECT

The following SQL statements and utilities are compatible with online backup only under certain circumstances:

CREATE INDEX
In SMS mode, online index create and online backup do not run concurrently due to the ALTER TABLE lock. Online index create acquires it in exclusive mode while online backup acquires it in share.

In DMS mode, online index create and online backup can run concurrently in most cases. There is a possibility if you have a large number of tables in the same tablespace as the one in which you are creating the index, that the online index create will internally acquire an online backup lock that will conflict with any concurrent online backup.
REORG INDEX with the ONLINE option
As with online index create, in SMS mode, online index reorganization do not run concurrently with online backup due to the ALTER TABLE lock. Online index reorganization acquires it in exclusive mode while online backup acquires it in share. In addition, an online index reorganization operation, quiesces the table before the switch phase and acquires a Z lock, which prevents an online backup. However, the ALTER TABLE lock should prevent an online backup from running concurrently before the Z table lock is acquired.

In DMS mode, online index reorganization and online backup can run concurrently.

In addition, online index reorganization quiesces the table before the switch phase and gets a Z lock, which prevents an online backup.
IMPORT
The import utility is compatible with online backup except when the IMPORT command is issued with the REPLACE parameter, in which case, import gets a Z lock on the table and prevents an online backup from running concurrently.
TRUNCATE TABLE
The TRUNCATE statement is not compatible with online backup because it gets a Z lock on the table and prevents an online backup from running concurrently.
ALLOW READ ACCESS LOAD
ALLOW READ ACCESS load operations are not compatible with online backup when the LOAD command is issued with the COPY NO parameter. In this mode the utilities both modify the table space state, causing one of the utilities to report an error.

ALLOW READ ACCESS load operations are compatible with online backup when the LOAD command is issued with the COPY YES option, although there might still be some compatibility issues. In SMS mode, the utilities can execute concurrently, but they will hold incompatible table lock modes and consequently might be subject to table lock waits. In DMS mode, the utilities both hold incompatible "Internal-B" (OLB) lock modes and might be subject to waits on that lock. If the utilities execute on the same table space concurrently, the load utility might be forced to wait for the backup utility to complete processing of the table space before the load utility can proceed.
REORG TABLE with the ONLINE option
The cleanup phase of online table reorganization cannot start while an online backup is running. You can pause the table reorganization, if required, to allow the online backup to finish before resuming the online table reorganization.

You can start an online backup of a DMS table space when a table within the same table space is being reorganized online. There might be lock waits associated with the reorganization operation during the truncate phase.

You cannot start an online backup of an SMS table space when a table within the same table space is being reorganized online. Both operations require an exclusive lock.
DDLs that require a Z lock (such as ALTER TABLE, DROP TABLE, and DROP INDEX)
Online DMS table space backup is compatible with DDLs that require a Z lock.

Online SMS table space backup must wait for the Z lock to be released.
Storage group DDLs
If you are modifying the database storage groups by issuing one of the following statements, you should take care to coordinate this operation with your online backup schedule:
- CREATE STOGROUP
- ALTER STOGROUP
- DROP STOGROUP
- RENAME STOGROUP
- ALTER DATABASE
If there is an online backup in progress, the storage group DDL waits behind that operation until it can obtain the appropriate lock, which can potentially take a long time. Similarly, an online backup waits behind any in-progress storage group DDL, until that DDL is committed or rolled back.
RUNSTATS with the ALLOW WRITE or ALLOW READ option
The RUNSTATS command is compatible with online backup except when the system catalog table space is an SMS table space. If the system catalog resides in an SMS table space, then the RUNSTATS command and the online backup hold incompatible table locks on the table causing lock waits.
ALTER TABLESPACE
Operations that enable or disable autoresize, or alter autoresize containers, are not permitted during an online backup of a table space.
ALTER TABLESPACE with the REBALANCE option
When online backup and rebalancer are running concurrently, online backup pauses the rebalancer and does not wait for it to complete.

The following utilities are not compatible with online backup:

REORG TABLE
RESTORE DATABASE
ROLLFORWARD DATABASE
LOAD with the ALLOW NO ACCESS option
SET WRITE
BACKUP DATABASE with the ONLINE option
This applies to database-level online backups and table-space-level online backups (if they involve the same table space or table spaces).