Patent ID: 11940997
Assignee: FUTUREWEI TECHNOLOGIES, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 19:
20. A non-transitory computer-readable media storing computer instructions, that when executed by one or more processors, cause the one or more processors to perform operations comprising:
parsing a query to generate first and second execution plans for the query, each execution plan of the first and second execution plans including one or more logical steps in a predefined canonical form, the predefined canonical form including at least one of: predefined keywords, fully qualified table names arranged in a predetermined order, or syntax templates;
retrieving, using a hash table in a database catalog, previously determined cardinality values for previously executed logical steps of the first and second execution plans, the hash table storing an entry for each logical step of the previously executed logical steps, and the entry relating a hash value of the predefined canonical form of the logical step to its cardinality value;
selecting an execution plan from the first execution plan or the second execution plan, with the selected execution plan having a lower cost based on the previously determined cardinality values; and
executing the selected execution plan using data from a database.