Migrated index storage space

Content Manager OnDemand supports automatic migration of indexes from the database to archive storage so that you can maintain seldom used indexes for long periods of time. However, migration of indexes should be done only after there is no longer a need to retrieve the reports to which they point. For example, suppose that all of the queries for a report occur in the first 24 months after the report is loaded into the system. After that time, there are almost no queries for the report. The indexes could be eligible to be migrated from the database to archive storage. Migration of index data is optional; you can choose to migrate indexes for all, some, or none of the application groups on your system. In addition, you determine the length of time that indexes stay in the database before Content Manager OnDemand migrates them to archive storage.

You can use the following calculation to determine the archive storage space required to hold migrated indexes:

Figure 1. Calculating migrated index storage space

     ArchiveMediaDBSpace = ( Database size per month * compression ratio )
                         * ( life of data - months before migrating data )

For example, if the index data requires 234 MB of space in the database per month, you need to maintain the indexes for 84 months, and the indexes remain in the database for 24 months before being migrated, then the archive storage required to hold the migrated indexes is:

     ArchiveMediaDBSpace  =  ( 234 MB  * .33 )
                          *  ( 84  -  24 )  =  4633200000

Content Manager OnDemand requires approximately 4.6 GB of archive storage to hold the migrated indexes.