LOBs with DB2 for z/OS: Stronger and Faster

234 LOBs with DB2 for z/OS: Stronger and Faster

Example 7-41 SPUFI update invalid LOB

UPDATE ##T.NORMEN03

SET IMAGE = BLOB('INVALID LOB')

WHERE DOC_ID LIKE '%E%' ;

---------+---------+---------+---------+---------+---------+

DSNE615I NUMBER OF ROWS AFFECTED IS 6

DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0

---------+---------+---------+---------+---------+---------+

---------+---------+---------+---------+---------+---------+

DSNE617I COMMIT PERFORMED, SQLCODE IS 0

DSNE616I STATEMENT EXECUTION WAS SUCCESSFUL, SQLCODE IS 0

Afterwards, CHECK LOB SHRLEVEL REFERENCE does not find invalid LOBs anymore and

the AUXW pending status on the LOB table space is reset.

More complicated scenarios could involve point in time recovery, but here the same

techniques apply as in the first scenario. The basic principles remain:

򐂰 LOBs with missing log records between the used image copy and the recovery point are

marked

invalid by RECOVERY and the LOB table space is put in the auxiliary warning

state

(AUXW). CHECK LOB is needed to identify the invalid LOBs, and SQL can be used

to populate them again using update or by deleting the entire row.

򐂰 If you do not recover the base table space and LOB table spaces together to a common

point of consistency, the base table space is marked as

auxiliary check pending (ACHKP).

CHECK DATA is needed to identify and invalidate the LOBs, which are no longer

synchronized between the base and LOB table space, and SQL can be used to populate

them again using update or by deleting the entire row.

7.2.3 NOT LOGGED base table space with NOT LOGGED LOB table space

In the third scenario, we create both the base table space as NOT LOGGED and the LOB

table space as NOT LOGGED. We then redo the following steps:

1. LOAD the data.

2. Create a common recoverable point of consistency using the COPY utility with LISTDEF

and SHRLEVEL REFERENCE as shown in Example 7-11 on page 221. In

SYSIBM.SYSCOPY, we now get a common START_RBA = X'0002BB16C862’.

3. Delete six LOBs using SPUFI as shown in Example 7-13 on page 222 to create some

update activity. As a result, both the base table space and the LOB table space and all

underlying indexes are put in the informational copy (ICOPY) status, because no changes

have been logged at all.

4. Stop and start all spaces of database NORMEN03 and delete the VSAM clusters using

ISPF 3.4 as shown in Example 7-14 on page 222.

5. Recover the VSAM clusters back to the current point with the same statements as shown

in Example 7-15 on page 222. The job output is shown in Example 7-42.

Example 7-42 RECOVER of NOT LOGGED objects

DSNU000I 223 18:37:16.58 DSNUGUTC - OUTPUT START FOR UTILITY, UTILID = RECOV.NORMEN03

DSNU1044I 223 18:37:16.64 DSNUGTIS - PROCESSING SYSIN AS EBCDIC

DSNU050I 223 18:37:16.65 DSNUGUTC - LISTDEF MYLIST INCLUDE TABLESPACES TABLE ##T.NORMEN03 ALL INCLUDE

INDEXSPACES TABLE ##T.NORMEN03 ALL

DSNU1035I 223 18:37:16.65 DSNUILDR - LISTDEF STATEMENT PROCESSED SUCCESSFULLY

DSNU050I 223 18:37:16.65 DSNUGUTC - RECOVER LIST MYLIST PARALLEL

DSNU1033I 223 18:37:16.67 DSNUGULM - PROCESSING LIST ITEM: TABLESPACE NORMEN03.NORMEN03