SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Performing Recovery Operations
HP NonStop SQL/MX Installation and Management Guide—523723-004
12-7
Recovering Database Objects
Recovering Database Objects
Recovering Range Partitions
This subsection pertains to range-partitioned tables only. Hash-partitioned tables
automatically redistribute data when they are dropped. Therefore, there is no need to
recover a hash partition that is accidentally dropped. Adding the partition will
automatically redistribute the data into the new hash partition.
A range partition must be empty to be dropped. However, you can recover a dropped
partition to a time when it was not empty by first specifying the original physical file
name of the partition and then re-adding it:
MODIFY TABLE CAT.SCH.T056T11
ADD PARTITION.....LOCATION \NSK.$DATA6.ZSDADLON.ONL42Q00
Next, recover the entire table and subordinate objects by using the complete set of
Guardian file names as indicated to ensure that all partitions are recovered to the same
state.
Using VERIFY and FIXUP
After using TMF RECOVER to recover partitions of an SQL/MX table, you should
perform a consistency check on all recovered files by using mxtool VERIFY. The
VERIFY command confirms that all data forks and resource forks exist and contain
consistent information.
When using mxtool VERIFY, specify the ANSI name of the table. For example, using
the same table name from the previous example:
mxtool VERIFY CAT.SCH.T039UC3
VERIFY performs these steps:
1. Compares metadata to information in the resource fork.
2. Compares metadata to information in the DP2 label.
3. Verifies the consistency of partition information.
Some inconsistencies reported as a result of this verification might be due to user
errors in the file recovery operation. For example, not all files to be recovered were
properly specified. However, even if the recovery was done correctly, VERIFY might
report inconsistencies between the labels and the metadata. In this case, you must run
the mxtool FIXUP command.
Note. Even though TMF supports recovery to different volumes and different systems,
SQL/MX database objects cannot be recovered to different disk volumes or to systems that
have different node names and numbers. To completely recover systems that contain SQL/MX
database objects, the backup and recovery system must have the same disk volume name,
node name, and node number as the primary system.