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ShardingSphere-JDBC
YAML Configuration
Rules
SQL Federation

SQL Federation

Background

This function is an experimental one and is currently not suitable for use in core system production environments. When multiple tables in a join query are distributed across different database instances, enabling federated query allows for cross-database join queries, as well as subqueries.

Parameters

sqlFederation:
  providerType: # SQL federation provider type; NONE disables federation and is the default
  allQueryUseSQLFederation: # all query use SQL federation configuration
  executionPlanCache: # execution plan cache configuration
    initialCapacity: 2000 # execution plan local cache initial capacity
    maximumSize: 65535 # execution plan local cache maximum size

When migrating an existing configuration, remove sqlFederationEnabled. Set providerType to NONE to disable federation, including configurations that previously used sqlFederationEnabled: false with another provider.

Sample

sqlFederation:
  providerType: CALCITE
  allQueryUseSQLFederation: false
  executionPlanCache:
    initialCapacity: 2000
    maximumSize: 65535

Related References

Single Table