Preparing for recovery by using the COPY utility

To prepare for recovery, you can use the COPY utility to create copies and establish points of recovery.

Use the following guidelines to help you prepare for recovery:

• Consider periodically merging incremental image copies into one copy.

  The RECOVER utility merges all incremental image copies since the last full image copy, and it must have all the image copies available at the same time. If this requirement is likely to strain your system resources (for example, by demanding more tape units than are available), consider regularly merging multiple image copies into one copy.

  Even if you do not periodically merge multiple image copies into one copy, when you do not have enough tape units, RECOVER can still attempt to recover the object. RECOVER dynamically allocates the full image copy and attempts to dynamically allocate all the incremental image copy data sets. If every incremental copy can be allocated, recovery proceeds to merge pages to table spaces and apply the log. If a point is reached where RECOVER cannot allocate an incremental copy, the log RBA of the last successfully allocated data set is noted. Attempts to allocate incremental copies cease, and the merge proceeds with only the allocated data sets. The log is applied from the noted RBA, and the incremental image copies that were not allocated are ignored.

• Create primary and backup image copies after a LOAD or REORG operation with LOG NO when an inline copy is not created. Create these copies, so that if the primary image copy is not available, fallback recovery with the secondary image copy is possible.
• If you use COPY SHRLEVEL REFERENCE to copy a list of referentially related structures, you do not need to quiesce these objects to create a consistent point of recovery. The copy serves as a point of consistency.
• For LOB data, quiesce and copy both the base table space and the LOB table space at the same time to establish a point of consistency for recovery. QUIESCE does not create a recovery point for a LOB table space that contains LOBs that are defined with LOG NO.
• If an index is in informational COPY-pending (ICOPY) status, take a full image copy of the index space so that the RECOVER utility can recover the index space.

  For an index that was defined with the COPY YES attribute the following utilities can place the index in ICOPY status:

  • REORG INDEX
  • REORG TABLESPACE LOG YES or NO
  • LOAD TABLE LOG YES or NO
  • REBUILD INDEX

  After the utility processing completes, take the full image copy. If you need to recover an index of which you did not take a full image copy, use the REBUILD INDEX utility to rebuild the index from data in the table space.

• Take image copies of table spaces with the NOT LOGGED attribute that have been updated since the last full copy.

  These table spaces are placed in ICOPY status. To copy the table spaces that have been updated, run the COPY utility with the SCOPE PENDING option.