CHECK LOB

You can run the CHECK LOB online utility on a LOB table space to identify any structural defects in the LOB table space and any invalid LOB values.

The CHECK LOB utility is useful in a variety of circumstances:

Run the utility on a LOB table space that is in CHECK-pending (CHKP) status to identify structural defects. If none are found, the CHECK LOB utility turns the CHKP status off.
Run the utility on a LOB table space that is in auxiliary-warning (AUXW) status to identify invalid LOBs. If none exist, the CHECK LOB utility turns AUXW status off.
Run the utility after a conditional restart or a point-in-time recovery on all table spaces where LOB table spaces might not be synchronized.
Run the utility before you run the CHECK DATA utility on a table space that contains at least one LOB column.

Output

After successful execution, CHECK LOB resets any CHECK-pending (CHKP) and auxiliary warning (AUXW) restrictive states. CHECK LOB SHRLEVEL CHANGE does not set the CHKP or AUXW states, even if the utility finds inconsistencies.

Authorization required

To execute this utility, you must use a privilege set that includes one of the following authorities:

STATS privilege for the database
DBADM, DBCTRL, or DBMAINT authority for the database. If the object on which the utility operates is in an implicitly created database, DBADM authority on the implicitly created database or DSNDB04 is required.
System DBADM authority
SYSCTRL or SYSADM authority

An ID with installation SYSOPR authority can also execute CHECK LOB.

If you are using SHRLEVEL CHANGE, the user ID that invokes COPY with the CONCURRENT option must provide the necessary authority to execute the DFSMSdss ADRDSSU command. DFSMSdss will create a shadow data set with the authority of the utility batch address space. The submitter should have a RACF® ALTER authority, or its equivalent, for the shadow data set.

Execution phases of CHECK LOB

The CHECK LOB utility operates in the following phases:

UTILINIT: Performs initialization
CHECKLOB: Scans all active pages of the LOB table space; generates up to four records per LOB page; passes records to the SORTIN phase
SORTIN: Passes CHECKLOB phase records to SORT
SORT: Sorts the records from the CHECKLOB phase
SORTOUT: Passes sorted records to the REPRTLOB phase
REPRTLOB: Examines records that are produced by the CHECKLOB phase; issues error messages
UTILTERM: Performs cleanup