Determining the set of tables to shadow

Use these tips to determine the optimal set of tables to shadow.

Maintain only useful shadow tables

Replicate only those tables that are referenced by key analytic queries. Maintaining a larger number of shadow tables has more overhead, and a larger latency tolerance might be required. Maintaining a larger number of shadow tables might also affect OLTP throughput, depending on the activity.

Ensure that all referenced tables have shadow tables

All tables that are referenced within a query must have associated shadow tables. Otherwise, none of the shadow tables are considered for use by the DB2® optimizer.