Proactive caching in olap databases

Abstract

The present invention leverages MOLAP performance for ROLAP objects (dimensions, partitions and aggregations) by building, in a background process, a MOLAP equivalent of that object. When the background processing completes, queries are switched from ROLAP queries to MOLAP queries. When changes occur to relevant relational objects (such as tables that define content of OLAP objects), an OLAP object is switched back to a ROLAP mode, and all relevant caches are dropped while, as a background process, a new MOLAP equivalent is created.

1 . A system for caching information, comprising: 
 a multidimensional objects interface that allows for accessing at least one multidimensional object;    a cache interface that allows for accessing and controlling at least one cache providing dynamic multidimensional analysis data derived from the multidimensional object; and    an analysis component that provides for proactively controlling access to the multidimensional object and the cache.    
   
   
       2 . The system of  claim 1 , the analysis component comprising 
 a query interpreter for receiving and qualifying queries based upon an input corresponding to proactively controlling the cache.    
   
   
       3 . The system of  claim 2 , the input being at least one of a user input and a system input.  
   
   
       4 . The system of  claim 1 , the analysis component further comprising an update component that automatically detects system conditions.  
   
   
       5 . The system of  claim 3 , the user input comprising at least one of a quiet time delay, a quiet time delay override, a forced refresh time, and a user initiated partial cache rebuild.  
   
   
       6 . The system of  claim 1 , the analysis component having proactive caching operational modes comprising at least one of a Relational On-line Analytical Processing (ROLAP) mode, a Multidimensional On-line Analytical Processing (MOLAP) mode, and a MOLAP and ROLAP hybrid (MOLAP/ROLAP) mode.  
   
   
       7 . The system of  claim 1 , the analysis component comprising an adaptive tuning component that optimizes the analysis component.  
   
   
       8 . The system of  claim 7 , the adaptive tuning component, comprising: 
 a query interpreter that handles queries and initiates query sessions with the multidimensional object and the cache;    a result comparator that determines differences between the query sessions of the multidimensional object and the cache; and    a performance optimizer that optimizes the query interpreter based on the differences determined by the result comparator.    
   
   
       9 . The system of  claim 1 , further comprising an On-line Transaction Processing (OLTP) component that facilitates interaction with an OLTP system.  
   
   
       10 . A method of proactive caching, comprising: 
 determining an operational mode of an analysis component based, at least in part, upon an input, the analysis component having different operational modes;    proactively building at least one cache providing dynamic multidimensional analysis data derived from at least one multidimensional object; and    proactively controlling the at least one cache based at least in part on the determined operational mode.    
   
   
       11 . The method of  claim 10 , further comprising: 
 switching the analysis component to the determined operational mode; and    processing queries via the analysis component utilizing the determined operational mode.    
   
   
       12 . The method of  claim 10 , further comprising: 
 determining if relevant multidimensional objects have changed; and    switching the analysis component operational mode to access the multidimensional objects when relevant changes have occurred.    
   
   
       13 . The method of  claim 12 , further comprising: 
 removing cache data related to the relevant changes; and    rebuilding the cache based on the changed multidimensional objects.    
   
   
       14 . The method of  claim 12 , determining if relevant multidimensional objects have changed comprising: 
 creating a list of tracking tables; and    utilizing the list of tracking tables to ascertain whether an object has changed.    
   
   
       15 . The method of  claim 10 , the input comprising at least one of one or more user inputs and one or more system inputs.  
   
   
       16 . The method of  claim 10 , further comprising determining whether a cache rebuild parameter has been satisfied.  
   
   
       17 . The method of  claim 16 , the cache rebuild parameter comprising at least one selected from the group consisting of a forced refresh rate, a quiet time delay, and a quiet time delay override.  
   
   
       18 . The method of  claim 10 , further comprising setting the operational mode to a MOLAP/ROLAP mode in response to at least one of both real-time and low latency queries and partial rebuilding of a MOLAP cache required.  
   
   
       19 . The method of  claim 10 , further comprising: 
 identifying relevant changes during the building of the cache;    canceling the building of the cache if relevant changes occur before the completion of the building of the cache; and    at least one input for determining when to proactively control the cache.    
   
   
       20 . A system for caching information, comprising: 
 means for providing dynamic multidimensional analysis data;    means for proactively building a cache containing a first multidimensional object and at least one equivalent object stored in a different format than the first multidimensional object; and    means for proactively controlling access to a cache and multidimensional data contained therein to provide a desired query response.