Concurrency and compatibility for CHECK DATA

The CHECK DATA 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 DATA operations
Target objects CHECK DATA DELETE NO CHECK DATA DELETE YES CHECK DATA PART DELETE NO CHECK DATA PART DELETE YES
Table space or partition DW/UTRO DA/UTUT DW/UTRO DA/UTUT
Partitioning index or index partition DW/UTRO DA/UTUT DW/UTRO DA/UTUT
Secondary index DW/UTRO DA/UTUT none DR
Logical partition of index none none DW/UTRO DA/UTUT
Primary index DW/UTRO DW/UTRO DW/UTRO DW/UTRO
RI dependent and descendent table spaces and indexes none DA/UTUT none DA/UTUT
RI exception table spaces and indexes (FOR EXCEPTION only) DA/UTUT DA/UTUT DA/UTUT DA/UTUT
Legend:
  • DA: Drain all claim classes, no concurrent SQL access
  • DR: Drain the repeatable read class, no concurrent access for SQL repeatable readers
  • DW: Drain the write claim class, concurrent access for SQL readers
  • UTUT: Utility restrictive state, exclusive control
  • UTRO: Utility restrictive state, read-only access allowed
  • none: Object not affected by this utility
  • RI: Referential Integrity

The following table shows claim classes on a LOB table space and an index on the auxiliary table.

Table 2. Claim classes of CHECK DATA operations on a LOB table space and index on the auxiliary table
Target objects CHECK DATA DELETE NO CHECK DATA DELETE YES
LOB table space DW/UTRO DA/UTUT
Index on the auxiliary table DW/UTRO DA/UTUT
Legend:
  • DW: Drain the write claim class, concurrent access for SQL readers
  • DA: Drain all claim classes, no concurrent SQL access
  • UTRO: Utility restrictive state, read-only access allowed
  • UTUT: Utility restrictive state, exclusive control

The following table shows claim classes of XML objects.

Table 3. Claim classes of XML objects
Target objects CHECK DATA DELETE NO CHECK DATA DELETE YES
XML table space DW/UTRO DA/UTUT
document ID and node ID indexes DW/UTRO DA/UTUT
XML index DW/UTRO DA/UTUT
Legend:
  • DW: Drain the write claim class, concurrent access for SQL readers
  • DA: Drain all claim classes, no concurrent SQL access
  • UTRO: Utility restrictive state, read-only access allowed
  • UTUT: Utility restrictive state, exclusive control

When you specify CHECK DATA AUXERROR INVALIDATE, a drain-all is performed on the base table space, and the base table space is set UTUT.

Compatibility

The following utilities are compatible with CHECK DATA and can run concurrently on the same target object:

  • DIAGNOSE
  • MERGECOPY
  • MODIFY
  • REPORT
  • STOSPACE
  • UNLOAD (when CHECK DATA DELETE NO)

SQL operations and other online utilities are incompatible.

To run on DSNDB01.SYSUTILX, CHECK DATA must be the only utility in the job step and the only utility that is running in the Db2 subsystem.

The index on the auxiliary table for each LOB column inherits the same compatibility and concurrency attributes of a primary index.