Recovery of compressed indexes

Additionally, BMC AMI Recover provides native support for

• Backout recovery of compressed indexes

• Recovery of encrypted compressed indexes

• Recovery of cabinet copies of compressed indexes

• Optimized merge recovery of compressed indexes

• Rebuilding compressed indexes

Two methods are available to make copies of compressed indexes. Each method has advantages and disadvantages.

• Make copies of compressed indexes by expanding them

  Both the IBM Db2 COPY utility and BMC AMI Copy can make copies of compressed indexes by reading the compressed indexes directly from disk and expanding them before writing the image copy. This method has the advantage that the copy is registered in SYSCOPY (and, in the case of BMC AMI Copy, the copy is compatible with those produced by the IBM Db2 COPY utility).

  Some disadvantages of this method are that it takes time to expand the pages and the resulting image copies are larger than necessary. Also, BMC AMI Copy copy techniques, such as Instant Snapshot copies and Online Consistent Copies, are not supported. (BMC AMI Copy will make unexpanded copies if you request an expanded copy.)

• Make copies of compressed indexes without expanding them

  BMC AMI Copy can make copies of the compressed indexes without expanding them. BMC AMI Copy registers these copies in the BMCXCOPY table. This method has the advantages that making the copies is faster and the copies are smaller than when copies are made of expanded indexes. Also, all BMC AMI Copy copy techniques, such as Instant Snapshots, Online Consistent Copy, encrypted copies, and cabinet copies, are supported.

  When you make copies of compressed indexes without expanding them, the copy is not compatible with the Db2 utilities and BMC AMI Recover is required to use these copies for recovery.

BMC AMI Recover supports both expanded and unexpanded copies of compressed indexes, and automatically determines the type of the copies that are available.

When you use BMC AMI Copy, the IXEXPAND option indicates which method you want to use to create copies of compressed indexes. Valid values are AUTO, YES, and NO. The default value is AUTO. IXEXPAND AUTO specifies that BMC AMI Copy will make unexpanded copies of compressed indexes if you are running with a Recovery Management for Db2 solution password (and consequently have BMC AMI Recover to recover using the unexpanded copies). If you are not running Recovery Management for Db2 solution, BMC AMI Copy will make expanded copies for compatibility with IBM. IXEXPAND NO specifies that compressed index copies are unexpanded. IXEXPAND YES specifies that compressed index copies are expanded. For more information on the IXEXPAND option, see  BMC AMI Copy for Db2 documentation .