ZOS - Comportamento ambiguo REORG lob tablespace LOG YES - COPY PENDING Status

Angelo Castriotta

ZOS - Comportamento ambiguo REORG lob tablespace LOG YES - COPY PENDING Status
Ho notato un comportamento strano e non prevedibile in seguito ad una
REORG TABLESPACE dbname.lobts LOG YES.
Il tablespace lob è stato creato con l'opzione LOG NO.

I manuali IBM non sono molto chiari e in alcune parti sono discordanti.

La DB2 Utility Guide riporta la seguente tabella:

Table 34. LOAD LOG and REORG LOG impact for a LOB table space


LOAD LOG/ LOB table space What is logged LOB
table space
REORG LOG LOG
attribute status after
keyword
utility completes
-----------------------------------------------------------------------------------------------------------------------------

LOG YES LOG YES Control information No
pending status
and LOB
data

LOG YES LOG NO Control information
No pending status <<<<--- Questo è il nostro caso
LOG NO LOG YES
Nothing COPY Pending
LOG NO LOG NO
Nothing COPY Pending


Perciò dalla tabella sopra mi aspetterei sempre come risultato un bel RC0
invece a volte la mia utility termina con un RC4 lasciandomi l'oggetto in
COPY Pending.

Facendo delle ricerche infatti ho trovato la seguente frase sempre
nell'Utility Guide nel paragrafo riguardante i parametri di REORG LOG YES |
NO
.
LOG
Specifies whether records are logged during the reload phase of REORG. If
the records are not logged, the table space is recoverable only after an
image copy has been taken. If you specify COPYDDN, RECOVERYDDN, SHRLEVEL
REFERENCE, or SHRLEVEL CHANGE, an image copy is taken during REORG
execution.

YES
Logs records during the reload phase. This option is not allowed for any
table space in DSNDB01 or DSNDB06, or if the SHRLEVEL REFERENCE or CHANGE
options are used.
If you specify SHRLEVEL NONE (explicitly or by default), the default is YES.


You must specify LOG YES (explicitly or by default) for a LOB table space.
Logging will occur only if the LOB table space was defined with the LOG YES
attribute.
If the LOB table space was defined with the LOG NO attribute, the LOB table
space will be left in COPY-pending status after the REORG.
.


E ancora dopo aver aperto un problema in IBM mi è stata inviata la seguente
frase:
.
In the utility book i see that sometimes a COPY PENDING status may
occur as results of LOB MANAGER decision:

6.2.7 REORG
...
If you use REORG SHRLEVEL NONE on a LOB table space and the LOB
Manager determines that nothing needs to be done to the table
space, no COPY pending status is set.
However, if the LOB Manager indicates that changes are needed,
REORG places the reorganized LOB table space or partition in COPY
pending status.
In this situation, perform a full image copy to reset the COPY
pending status and to ensure that a backup is available for
recovery.


According to table 34
2.12.2.4.10 Using LOAD LOG on a LOB table space

Performing a LOG=YES REORG on a LOG=NO LOB should never leave a
pending condition, but maybe sometimes it is still required as
reported above.

Qualcuno di voi ha avuto una esperienza simile ed è riuscito a capire chi
dice la verità? ;-)


Grazie.
Ciao!

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