Intelligent page store for concurrent and consistent access to a database by a transaction processor and a query processor

A database transaction and query processing system for simultaneously running transactions and queries against the same database without ever having a transaction wait for a query to complete or ever having a query wait for a transaction to complete, comprising:

• an intelligent page store for non-volatile storage of a primary version of each page of a database and for creating and maintaining at least one consistent snapshot version of said database for access by queries which do not require access to the most recently updated database pages, said intelligent page store maintaining only one physical copy of any page of said database which is the same in said primary version and said at least one snapshot version of said database;
• a transaction processor having a buffer for receiving needed pages of said primary version of said database from said intelligent page store,
• said transaction processor running transactions only against said pages of said data base stored in said buffer of said transaction processor and forming an updated version of at least some of said pages stored in said buffer,
• said transaction processor sending back to said intelligent page store any updated pages of said database which are replaced in said buffer of said transaction processor,
• a most recently committed version of any particular page of said database possibly being stored in said buffer of said transaction processor instead of in said intelligent page store at any particular arbitrary time;
• and
• a query processor independent of said transaction processor for running queries against said at least one consistent snapshot version of said database, said at least one consistent version of said database being made available by said intelligent page store to said query processor;
• wherein said intelligent page store creates a consistent snapshot version of said database by flushing said page buffer into said intelligent page store, said primary version of said database after said flushing being the consistent snapshot version.