Specifying query optimization settings
In Server Configuration Templates—Settings—Integration Service—Query Management—Query Optimization, shown in
Figure 10‑7, the administrator sets properties to improve the overall system performance. iHub reduces the execution time and system resource usage for queries across multiple data sources.
The properties are:
Enable cost-based optimization
Determines whether to apply the cost-based query optimization.
Change the default value when the query plans generated with cost-based optimization are inefficient or when you cannot provide the cost information for the information objects.
Minimum rows to trigger creation of an index during materialize operation
Creates an index on materialization that improves performance of searching for matched tuples in the materialization.
When the materialization has more rows than this parameter value, iHub creates the index.
Increase the default value when iHub executes too many concurrent queries, exhausting the memory for indexing and impacting overall system performance.
Reduce the number of queries that invoke the creation of an index, thereby slowing the execution of some queries and reducing system resource usage.
Figure 10‑7 Specifying Integration service query optimization settings
