The OpenAccess SDK SQL engine and the IP work together to execute a query. The OpenAccess SDK SQL engine is responsible for:
• Parsing the query to check the syntax and to generate the expression tree.
• Breaking the query into primitive operations: SELECT, INSERT, DELETE, and UPDATE.
• Executing the primitive operations using the EXECUTE function in the IP.
• Supporting the IP in expression evaluation, data management, and optimization.
The IP is responsible for:
• Implementing the IP API functions to handle reading and writing to the tables exposed in the schema. The IP uses the OpenAccess SDK SQL engine functions for optimization and data management.
• Optionally performing any sorting/grouping if capable.
• Optionally performing any JOINS if capable.
• Implementing custom scalar functions and stored procedures.
With this in mind, the following example first describes a sample database system and then describes the operations the OpenAccess SDK SQL engine and the IP perform to execute a sample query.
