MODIFY RECOVERY

Output

In addition to deleting catalog and directory records and entries from the DBD, MODIFY RECOVERY can also affect the following items:

Image copy data sets

If you specify the DELETEDS option, MODIFY RECOVERY deletes the image copy data sets that correspond to the deleted SYSCOPY records. Image copy data sets with an expiration date are deleted even if unexpired.

SYSIBM.SYSCOPY records

In most cases, MODIFY RECOVERY inserts a row into SYSIBM.SYSCOPY to record the RBA or LRSN of the most recently deleted SYSCOPY or SYSLGRNX record. That row has ICTYPE='M' and STYPE='R'. If MODIFY RECOVERY is run at the table space level, this row is inserted for each partition of the table space and any partitioned indexes with the COPY YES attribute that the utility processes.

MODIFY RECOVERY does not insert this row in SYSCOPY when no SYSLGRNX rows are deleted or when the only SYSCOPY rows that were deleted are rows with the following values:

• ICTYPE='F' and STYPE is blank (full image copy)
• ICTYPE='F' and STYPE='C' (concurrent copy of the "I" instance)
• ICTYPE='F' and STYPE='J' (concurrent copy of the "J" instance)
• ICTYPE='I' (incremental image copy)
• ICTYPE='Q' (quiesce point)

COPY-pending status

If MODIFY RECOVERY deletes at least one SYSCOPY record, and the target table space or partition is not recoverable from remaining SYSCOPY records or from system-level backups, the target object is placed in COPY-pending status.The exception is if the NOCOPYPEND option is specified. In this case, the object is not placed in COPY-pending status, and the job completes with a return code of 0 if no other errors or warnings exist.

Version numbers

For table spaces and indexes that are defined with COPY YES, MODIFY RECOVERY updates the OLDEST_VERSION column of the following catalog tables:

• SYSIBM.SYSTABLESPACE
• SYSIBM.SYSTABLEPART
• SYSIBM.SYSINDEXES
• SYSIBM.SYSINDEXPART

When MODIFY RECOVERY deletes all of the SYSCOPY records that contain an OLDEST_VERSION value of 0 for a table space, MODIFY RECOVERY deletes the corresponding rows for that table space from SYSIBM.SYSOBDS. The reason is because point-in-time recovery for the table space is no longer possible.

Authorization required

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

• IMAGCOPY privilege for the database
• System DBADM authority
• DBADM authority
• SYSCTRL or SYSADM authority
• 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.

An ID with installation SYSOPR authority can also execute MODIFY RECOVERY, but only on a table space in the DSNDB01 or DSNDB06 database.

Execution phases of MODIFY RECOVERY

The MODIFY RECOVERY utility operates in these phases:

UTILINIT

Initialization and setup.

MODIFY

Records are deleted.

DELETEDS

When the DELETEDS option is specified, cataloged image copy data sets are deleted.

UTILTERM

Cleanup.

Option descriptions

LIST listdef-name

Specifies the name of a LISTDEF list. This list must contain only table spaces or table space partitions. MODIFY RECOVERY processes each object in the list.

Related information:

• Referencing LISTDEF lists in other utility jobs

TABLESPACE

Specifies the table space for which records are to be deleted.

database-name.table-space-name

The name of the database and table space. The default value for database-name is DSNDB04.

DSNUM integer

Identifies a single partition or data set for which records are to be deleted.

integer

The number of the partition or data set.

For a partitioned table space, specify the physical partition number. The maximum is 4096.

For a nonpartitioned table space, use the data set integer at the end of the data set name as cataloged in the VSAM catalog. The data set name has the following format:

catname.DSNDBx.dbname.tsname.y000z.Annn

where y is either I or J, z is either a 1 or 2, and nnn is the data set integer.

If you specify DSNUM integer, MODIFY RECOVERY does not delete any partition SYSCOPY records that have an RBA that is greater than that of the earliest point to which the entire table space could be recovered. (That point might indicate a full image copy, a LOAD operation with LOG YES or a REORG operation with LOG YES.)

If the partition that you specify is in PRO restricted status, the RETAIN value is set to LAST(2).

If you specify DSNUM integer for a partitioned table space, MODIFY RECOVERY also deletes SYSCOPY records for all partitioned index spaces and updates the version numbers in the SYSIBM.SYSINDEXES catalog table. Db2 does not perform these functions for the nonpartitioned indexes.

ALL

Records are deleted for the entire data set and table space. The default value is ALL.

If image copies are taken by partition or data set and you specify DSNUM ALL, the table space is placed in COPY-pending status if a full image copy of the entire table space does not exist.

If DSNUM ALL is implicitly or explicitly specified for a table space that has a partition in PRO restricted status, MODIFY RECOVERY fails.

CLONE

Indicates that MODIFY RECOVERY is to delete SYSCOPY and SYSLGRNX records for only clone objects. If CLONE is not specified, only records for the base objects are deleted.

If you want MODIFY RECOVERY to process clone objects in a LISTDEF list, specify CLONE in the MODIFY RECOVERY statement. (The CLONED YES option in the LISTDEF statement only specifies whether to include clone objects in list; it has no effect on whether MODIFY RECOVERY processes those objects.)

DELETE

Indicates that records are to be deleted.

AGE integer

Deletes all SYSCOPY and SYSLGRNX records that are older than the specified number of days.

integer

The number of days. The value can range from 0 to 32767. Records that are created today are of age 0 and cannot be deleted by this option.

(*)

Deletes all records, regardless of their age.

DATE integer

Deletes all SYSCOPY and SYSLGRNX records that were written before the specified date.

integer

The date. Specify this value in eight- or six-character format: yyyymmdd or yymmdd, where yyyy or yy is the year, mm is the month, and dd is the day.

If you specify a six-character date, Db2 checks the system clock and converts the date to the most recent, previous eight-character equivalent.

(*)

Deletes all records, regardless of the date on which they were written.

SYSLGRNX records that meet the specified deletion criteria are deleted even if no SYSCOPY records are deleted. One exception exists: in a non-data sharing environment, if no SYSLGRNX records were created in DB2® 9 new-function mode or later and no SYSCOPY records are deleted, MODIFY RECOVERY does not deletes SYSLGRNX records, even if they fit the deletion criteria.

FLASHCOPY ONLY

Indicates that records for only FlashCopy® image copies are to be deleted. The utility deletes SYSIBM.SYSCOPY records for FlashCopy image copies according to the options that are specified in the DELETE or RETAIN clause.

SYSCOPY records for a FlashCopy image copy are deleted only if an equivalent sequential image copy exists. An equivalent sequential image copy is a copy that was created from the FlashCopy image copy by the COPY or COPYTOCOPY utility. It has the same START_RBA, PIT_RBA, and DSVOLSER column values in its SYSIBM.SYSCOPY record as the FlashCopy image copy. Records for the FlashCopy image copy are not deleted if uncommitted work was backed out of a FlashCopy image copy with consistency and the equivalent sequential image copy is not cataloged.

When FLASHCOPY ONLY is specified, MODIFY RECOVERY does not delete SYSIBM.SYSLGRNX and SYSIBM.SYSOBDS records or update DBD entries and data versions. Additionally, the utility does not insert a SYSIBM.SYSCOPY record with ICTYPE=M and STYPE=R, because the recoverability of the object is not affected.

Related information:

• Backing up data efficiently by using FlashCopy image copies

RETAIN

Indicates that certain records are to be retained. Older records are deleted.

LAST (integer)

Specifies the number of recent records to retain in SYSIBM.SYSCOPY.

LOGLIMIT

Deletes records that are older than the oldest archive log timestamp. For data sharing, this value is the oldest archive log timestamp across all the members.

The utility determines the oldest archive log timestamp by querying the BSDS. If the BSDS is not available for one of the members and the corresponding member is quiesced, this BSDS is ignored.

If you use a replication product that reads Db2 log records, consider using the RETAIN LOGLIMIT option to ensure that the version information for table spaces and indexes is retained with the same duration as the logs.

GDGLIMIT

If the most recent record in SYSIBM.SYSCOPY refers to a generation data set (GDS), GDGLIMIT specifies that the utility is to consider only those records that reference the same GDG and retain as many as it can without exceeding the GDG limit value.

Db2 does not consider other GDGs that are referenced by SYSIBM.SYSCOPY records. The records that reference other GDGs are deleted in accordance with the deletion date.

LAST (integer)

If the most recent record in SYSIBM.SYSCOPY does not refer to a GDS, LAST specifies the number of recent records to retain in SYSIBM.SYSCOPY.

LOGLIMIT

If the most recent record in SYSIBM.SYSCOPY does not refer to a GDS, LOGLIMIT deletes records that are older than the oldest archive log timestamp.

When you specify RETAIN, the utility determines a cleanup date by checking SYSCOPY records. The utility considers only local primary full image copies (ICTYPE=F and ICBACKUP=blank) with the specified DSNUM value. The utility determines a date, not a complete timestamp. As a result, more copies might be kept than are specified by RETAIN. For example, if you specify RETAIN LAST (2) and the most recent five copies have been taken on the same day, all five copies remain in SYSCOPY.

DELETEDS

Specifies that cataloged image copy data sets are to be deleted when the corresponding SYSCOPY records are deleted. Image copy data sets with an expiration date are deleted even if unexpired.

The following data sets are deleted:

• Cataloged image copy data sets that reside on disk or that have been migrated to tape by DFSMShsm
• Cataloged sequential image copies, including inline image copies
• FlashCopy image copies
• Sequential image copies that are generation data sets (GDS) in a generation data group (GDG)

NOCOPYPEND

Specifies that the table space is not to be placed in COPY-pending status if MODIFY RECOVERY deletes all image copy records from SYSIBM.SYSCOPY.

NOCOPYPEND does not remove any COPY-pending status that was set prior to the MODIFY RECOVERY utility being run. NOCOPYPEND also does not set informational COPY-pending (ICOPY) status for indexes.

Specify NOCOPYPEND only if the data in the table space can be easily re-created if the data is lost. If an image copy is not taken after MODIFY RECOVERY is run, the table space cannot be recovered by using the RECOVER utility and data might be lost.

Before running MODIFY RECOVERY

Before you run MODIFY RECOVERY, complete the following actions:

• Make sure that DSNDB01.SYSLGRNX is not in a restrictive state. Because MODIFY RECOVERY updates DSNDB01.SYSLGRNX, any restrictive status on this table space might cause the utility to abend.

  A prior MODIFY RECOVERY run on DSNDB01.SYSLGRNX could inadvertently lead to this situation. For example, if all recovery information was deleted by the specified age or date criteria, DSNDB01.SYSLGRNX is set to COPY-pending status.

• Reset RECOVER-pending status for any table spaces on which you plan to run MODIFY RECOVERY. You cannot run MODIFY RECOVERY on a table space that is in RECOVER-pending status.
• Recommendation: If you plan to use MODIFY RECOVERY to delete SYSCOPY records, first run the REPORT utility with the RECOVERY option. This utility reports all SYSCOPY records for the object at the specified site. Looking at this report first helps you avoid deleting the wrong records.
• Recommendation: To improve the performance of MODIFY RECOVERY and reduce contention on SYSLGRNX, run the REORG TABLESPACE utility on DSNDB01.SYSLGRNX on a regular basis.

Data sets that MODIFY RECOVERY uses

MODIFY RECOVERY always requires the following two data sets:

Concurrency and compatibility for MODIFY RECOVERY

During processing, MODIFY RECOVERY sets the claim class of the target table space or partition to UTRW (Utility restrictive state - Read-write access allowed).

MODIFY RECOVERY can run concurrently with any utility on the same target object.

Termination or restart of MODIFY RECOVERY

You can use the TERM UTILITY command to terminate MODIFY RECOVERY in any phase without any integrity exposure.

You can restart a MODIFY RECOVERY utility job, but it starts from the beginning again.