Query processors
The query processor is the subcomponent of the data server that processes SQL requests. The SQL requests can access a single database or file system or reference multiple types of databases or file systems.
- Single-phase commit query processor (CACQP)
- Accesses and joins information from multiple data sources and performs updates to a single data source.
- Two-phase commit query processor (CACQPRRS)
- Accesses and joins information from multiple data sources and
performs updates to multiple data sources. The two-phase commit query
processor uses z/OS® Resource Recovery Services to coordinate
the data source updates. This query processor can participate in distributed
transactions by using a JDBC client and a distributed transaction
manager (such as WebSphere® Application Server).
The two-phase commit query processor supports the CA-Datacom, DB2® for z/OS, IMS, and transactional VSAM data sources.
You cannot mix these two types of query processors within a single data server.
The data server configuration must include a service definition for a query processor.
The query processor handles requests from the Classic JDBC, ODBC, and CLI clients in form of SQL. It invokes one or more connectors to access the target database, file system, or stored procedures that are referenced in a SQL request from the client.
By using native database and file facilities, the query processor maintains the structural integrity and the performance characteristics of the data source.