Generation of a query plan for accessing a database

A method of generating a query plan for accessing a database, comprising:

• receiving one or more electronic queries from a database client;
• determining whether the received one or more queries form a part of a set of ordered queries comprising a repeating sequence of a plurality of queries, by determining whether the received one or more queries match a part of the sequence of queries;
• determining a Quality of Service measure:
• and
• if the received one or more queries are determined to form a part of the set of ordered queries, retrieving a stored query plan for executing one or more queries in the sequence that match the received one or more queries, and a query that is subsequent to the matching one or more queries in the sequence,
• wherein the query plan is selected from a plurality of stored query plans associated with the received one or more queries, the process of selecting a query plan comprising selecting a query plan from the plurality of stored query plans associated with the received one or more queries by comparing the determined Quality of Service measure with a respective Quality of Service figure associated with each of the plurality of query plans and selecting a query plan in dependence on the results of the comparison.

An apparatus operable to generate a query plan for accessing a database, the apparatus comprising:

• a receiver operable to receive one or more electronic queries from a database client;
• a Quality of Service determining unit operable to determine a Quality of Service measure;
• a pattern detection unit operable to determine whether the received one or more queries form a part of a set of ordered queries comprising a repeating sequence of a plurality of queries by determining whether the received one or more queries match a part of the sequence of queries;
• and
• a query plan generator operable to retrieve a stored a query plan for executing one or more queries in the sequence that match the received one or more queries, and a query that is subsequent to the matching one or more queries in the sequence,
• wherein the query plan generator is operable to select the query plan from a plurality of stored query plans associated with the received one or more queries by comparing the determined Quality of Service measure with a respective Quality of Service figure associated with each of the plurality of query plans, and selecting a query plan in dependence on the results of the comparison.