Method and system for controlling concurrent access to data in a database system

Abstract

A method and system for controlling concurrency of access to data in a database system is provided. The method includes receiving a lock request for access to data in the database system, in which the lock request is a request for a page lock or a row lock for a corresponding row or page in the database system containing the data. The method further includes identifying a partition in the database system that contains the row or the page in the database system containing the data; associating the lock request with a partition lock on the partition that contains the row or the page in the database system containing the data; and accessing the data using the partition lock.

1 . A method for controlling concurrency of access to data in a database system, the method comprising: 
 receiving a lock request for access to data in the database system, the lock request being a request for a page lock or a row lock for a corresponding row or page in the database system containing the data;    identifying a partition in the database system that contains the row or the page in the database system containing the data;    associating the lock request with a partition lock on the partition that contains the row or the page in the database system containing the data; and    accessing the data using the partition lock.    
   
   
       2 . The method of  claim 1 , further comprising: 
 responsive to the data being committed at a time of receiving the lock request, accessing the data without using the partition lock.    
   
   
       3 . The method of  claim 1 , wherein accessing the data using the partition lock includes serializing access to the partition at a lock state to protect against interference in the form of updates to the partition.  
   
   
       4 . The method of  claim 3 , wherein serializing access to the partition includes permitting lock requests access to the partition that are compatible with the lock state.  
   
   
       5 . The method of  claim 4 , further comprising: 
 receiving a lockmax value;    accumulating for an application, a number of lock requests for access to the data in the database system by the application;    comparing the number of lock requests with the lockmax value; and    when the number of lock requests equals the lockmax value, escalating the lock state.    
   
   
       6 . The method of  claim 1 , wherein accessing the data using the partition lock comprises an application accessing the data through a single database system.  
   
   
       7 . The method of  claim 1 , wherein accessing the data using the partition lock comprises a second database system in a data-sharing environment accessing the data.  
   
   
       8 . The method of  claim 1 , wherein the lock request is a request for a shared lock or an exclusive lock.  
   
   
       9 . A computer readable medium encoded with a computer program for controlling concurrency of access to data in a database system, the computer program comprising computer executable instructions for: 
 receiving a lock request for access to data in the database system, the lock request being a request for a page lock or a row lock for a corresponding row or page in the database system containing the data;    identifying a partition in the database system that contains the row or the page in the database system containing the data;    associating the lock request with a partition lock on the partition that contains the row or the page in the database system containing the data; and    accessing the data using the partition lock.    
   
   
       10 . The computer readable medium of  claim 9 , wherein the computer program further comprises computer executable instructions for: 
 accessing the data without using the partition lock responsive to the data being committed at a time of receiving the lock request.    
   
   
       11 . The computer readable medium of  claim 9 , wherein the computer executable instructions for accessing the data using the partition lock include computer executable instructions for serializing access to the partition at a lock state to protect against interference in the form of updates to the partition.  
   
   
       12 . The computer readable medium of  claim 11 , wherein the computer executable instructions for serializing access to the partition include computer executable instructions for permitting lock requests access to the partition that are compatible with the lock state.  
   
   
       13 . The computer readable medium of  claim 12 , wherein the computer program further comprises computer executable instructions for: 
 receiving a lockmax value;    accumulating for an application, a number of lock requests for access to the data in the database system by the application;    comparing the number of lock requests with the lockmax value; and    when the number of lock requests equals the lockmax value, escalating the lock state.    
   
   
       14 . The computer readable medium of  claim 9 , wherein the computer executable instructions for accessing the data using the partition lock include computer executable instructions for having an application access the data through a single database system.  
   
   
       15 . The computer readable medium of  claim 9 , wherein the computer executable instructions for accessing the data using the partition lock c include computer executable instructions for having a second database system in a data-sharing environment accessing the data.  
   
   
       16 . A database management system implemented in a digital computer system, the database management system configured to manage access to data in a database system, the database management system comprising: 
 a data manager configured to: 
 receive a lock request for access to data in the database system, the lock request being a request for a page lock or a row lock for a corresponding row or page in the database system containing the data;  
 identify a partition in the database system that contains the row or the page in the database system containing the data;  
 associate the lock request with a partition lock on the partition that contains the row or the page in the database system containing the data; and  
 access the data using the partition lock.  
   
   
   
       17 . The database management system of  claim 16 , wherein the data manager is further configured to access the data without using the partition lock responsive to the data being committed at a time the data manager received the lock request.  
   
   
       18 . The database management system of  claim 16 , further comprising a lock manager configured to grant serialized access to the partition at a lock state to protect against interference in the form of updates to the partition.  
   
   
       19 . The database management system of  claim 18 , wherein the lock manager serializes access to the partition by granting lock requests on the partition that are compatible with the lock state.  
   
   
       20 . The database management system of  claim 18 , wherein the lock manager is coupled to a plurality of database systems of a data-sharing environment.