Deciding whether to cache a generic plan for executing a request based on a system performance metric

A computer program, stored in a non-transitory tangible medium, the program comprising executable instructions that cause a computer to:

• receive a plurality of instances of a request to a database system, all instances of the request having a same set of variables to use in executing the request, the values of the variables being supplied by data in a data source;
• generate a specific plan for executing one instance of the request, wherein when generating the specific plan the computer takes into account data in the data source;
• execute the specific plan on the database system;
• capture and save a system run-time metric and a parsing time for executing the specific plan;
• and
• decide to generate and cache a generic plan based on a comparison of the system run-time metric and the parsing time for executing the specific plan.

A database system, the system comprising:

• one or more nodes;
• a plurality of CPUs, each of the one or more nodes providing access to one or more CPUs;
• a plurality of virtual processes, each of the one or more CPUs providing access to one or more virtual processes;
• each virtual process configured to manage data, including rows from the set of database table rows, stored in one of a plurality of data-storage facilities;
• a program configured to:
• receive a plurality of instances of a request to a database system, all instances of the request having a same set of variables to use in executing the request, the values of the variables being supplied by data in a data source;
• generate a specific plan for executing one instance of the request, wherein when generating the specific plan the computer takes into account data in the data source;
• execute the specific plan on the database system;
• capture and save a system run-time metric and a parsing time for executing the specific plan;
• and
• decide to generate and cache a generic plan based on a comparison of the system run-time metric and the parsing time for executing the specific plan.