DATABASE CACHING OF QUERIES AND STORED PROCEDURES USING DATABASE PROVIDED FACILITIES FOR DEPENDENCY ANALYSIS AND DETECTED DATABASE UPDATES FOR INVALIDATION

摘要

Database data is maintained reliably and invalidated based on actual changes to data in the database. Updates or changes to data are detected without parsing queries submitted to the database. The dependencies of a query can be determined by submitting a version of the received query to the database through a native facility provided by the database to analyze how query structures are processed. The caching system can access the results of the facility to determine the tables, rows, or other partitions of data a received query is dependent upon or modifies. An abstracted form of the query can be cached with an indication of the tables, rows, etc. that queries of that structure access or modify. The tables a write or update query modifies can be cached with a time of last modification. When a query is received for which the results are cached, the system can readily determine dependency information for the query, the last time the dependencies were modified, and compare this time with the time indicated for when the cached results were retrieved. By passing versions of write queries to the database, updates to the database can be detected.