Execution of database queries including filtering

Abstract

A query processing system has a query processor and a data manager. The query processor calls the data manager to carry out data access for a query including a filtering operation. The data manager accesses the data in a set of data and before returning the data, initiates a callback to the query processor to determine if the located data meets the filtering criteria. Where the data does not satisfy the filtering criteria, the data manager seeks additional data in the set of data, without having to return the first located data to the query processor.

1 - 16 . (cancelled).  
   
   
       17 . A query processing system comprising: 
 a data manager for accessing data records located in pages in a set of stored data, the data manager stabilizing a page on which a data record is stored before accessing the record, and    a query processor for processing a data access plan, the query processor calling the data manager and the query processor indicating to the data manager that a query being processed includes a designated filtering operation, 
 where the data manager receives the indication of a designated filtering operation, the data manager stabilizing a current data page containing a located record in the set of stored data, the data manager applying the designated filtering operation to the located record before releasing the stabilization of the current data page.  
   
   
   
       18 . The query processing system of  claim 17 , in which the data manager applies the designated filtering operation to the located record by calling the query processor to carry out the filtering operation.