In this phase, upgrade-specific indices are created to improve migrator performance. This phase starts by creating upgrade indices in background threads. When a migrator that is dependent on an index executes, the migrator verifies whether the index is completed before executing. If it has not finished being created, the migrator will not execute until the index is done.

There is a property in the db.properties file that can be configured to set the overall amount of time to wait for any given index to be created. The default value is one hour, specified in milliseconds. The property is as follows:

If this time is exceeded, the upgrade will fail due to the timeout. If the upgrade continues, these performance indices are dropped in the Drop Upgrade Indices phase. For information, see Drop Upgrade Indices.