Concurrency and compatibility for CHECK INDEX

The CHECK INDEX utility has certain concurrency and compatibility characteristics associated with it.

Db2 treats individual data and index partitions as distinct target objects. Utilities that operate on different partitions of the same table space or index space are compatible.

Claims and drains

The following table lists any claims or drains that the utility acquires and any restrictive states that are set on the target object.

Table 1. Claim classes of CHECK INDEX operations
Target	CHECK INDEX SHRLEVEL REFERENCE	CHECK INDEX PART SHRLEVEL REFERENCE	CHECK INDEX SHRLEVEL CHANGE	CHECK INDEX PART SHRLEVEL CHANGE
Table space or partition	DW/UTRO	DW/UTRO	DW/UTRW	DW/UTRW
Partitioning index or index partition	DW/UTRO	DW/UTRO	DW/UTRW	DW/UTRW
Secondary index¹	DW/UTRO	none	DW/UTRW	DW/UTRW
Data-partitioned secondary index or index partition²	DW/UTRO	DW/UTRO	DW/UTRW	DW/UTRW
Logical partition of an index	none	DW/UTRO	DW/UTRW	DW/UTRW
Legend: DW: Drain the write claim class, concurrent access for SQL readers UTRO: Utility restrictive state, read only-access allowed UTRW: Utility restrictive state, read and write access allowed none: Object not affected by this utility Note: Includes document ID indexes and node ID indexes over non-partitioned XML table spaces and XML indexes. Includes document ID indexes and node ID indexes over partitioned XML table spaces.

CHECK INDEX does not set a utility restrictive state if the target object is DSNDB01.SYSUTILX.

CHECK INDEX of an XML index cannot run if REBUILD INDEX, REORG INDEX, or RECOVER is being run on that index because CHECK INDEX needs access to the node ID index. CHECK INDEX SHRLEVEL CHANGE cannot run two jobs concurrently for two different indexes that are in the same table space or partition because the snapshot shadow will have a conflicting name for the table space.

Compatibility

The following table shows which utilities can run concurrently with CHECK INDEX on the same target object. The first column lists the other utility and the second column lists whether or not that utility is compatible with CHECK INDEX. The target object can be a table space, an index space, or an index partition. If compatibility depends on particular options of a utility, that information is also documented in the table.

Table 2. Compatibility of CHECK INDEX SHRLEVEL REFERENCE with other utilities
Action	Compatible with CHECK INDEX?
CHECK DATA	No
CHECK INDEX.	Yes
CHECK LOB	Yes
COPY INDEXSPACE	Yes
COPY TABLESPACE	Yes
DIAGNOSE	Yes
LOAD	No
MERGECOPY	Yes
MODIFY	Yes
QUIESCE	Yes
REBUILD INDEX	No
RECOVER INDEX	No
RECOVER TABLESPACE	No
REORG INDEX	No
REORG TABLESPACE UNLOAD CONTINUE or PAUSE	No
REORG TABLESPACE UNLOAD ONLY or EXTERNAL	Yes
REPAIR DELETE or REPLACE	No
REPAIR DUMP or VERIFY	Yes
REPORT	Yes
RUNSTATS	Yes
STOSPACE	Yes
UNLOAD	Yes

An instance of CHECK INDEX can run on SYSIBM.DSNLUX01 or SYSIBM.DSNLUX02 only if that instance is the only utility within a job step. In addition, an instance of CHECK INDEX with SHRLEVEL REFERENCE as a specified or default value can run on SYSIBM.DSNLUX01 or SYSIBM.DSNLUX02 only if that instance is the only utility that is running in the Db2 subsystem.