System and method for quiescing select data modification operations against an object of a database during one or more structural operations

Abstract

The invention is a reorganization system having a reorganization application, a database management system, and one or more database files. The reorganization application communicates with the database management system and the one or more database files to reorganize an object, such as, for example, a table or index, while providing one or more clients substantially continuous access to the object. The reorganization application employs one or more trigger locks to synchronize the data in an original table and a reorganized table. The one or more trigger locks block select data modification operations while allowing one or more read-only operations and structural modification operations.

1 . A method of reorganizing an object in a database file, the method comprising: 
 reorganizing an original object by copying data of the original object to a reorganized object;    applying a first partial lock to the original object, the first partial lock configured to block select data modification operations against the original object;    substituting the reorganized object for the original object; and    applying a second partial lock to the reorganized object, the second partial lock configured to block select data modification operations to the reorganized object during said substituting.    
   
   
       2 . The method of  claim 1 , wherein the second partial lock is configured to allow at least one read-only operation against the reorganized object.  
   
   
       3 . The method of  claim 2 , wherein the first partial lock is configured to allow at least one structural modification operation against the original object.  
   
   
       4 . The method of  claim 1 , wherein the reorganized object remains accessible during said substituting of the reorganized object for the original object.  
   
   
       5 . The method of  claim 1 , wherein said substituting further comprises: 
 changing a name of the original object from a first name to a second name; and    assigning the reorganized object the first name.    
   
   
       6 . The method of  claim 1 , further comprising archiving the original object.  
   
   
       7 . The method of  claim 1 , additionally comprising synchronizing, prior to said applying the second partial lock, the original object and the reorganized object with each other.  
   
   
       8 . The method of  claim 1 , additionally comprising removing the second partial lock, wherein additional more-restrictive locks to the original object are not needed during the method of reorganizing the original object.  
   
   
       9 . A computer-executable software program for a database system, the software program comprising: 
 first software instructions capable of reorganizing an original object of a database by copying data of the original object to a reorganized object;    second software instructions capable of applying a first partial lock to the original object, the first partial lock configured to block select data modification operations against the original object;    third software instructions capable of substituting the reorganized object for the original object; and    fourth software instructions capable of applying a second partial lock to the reorganized object, the second partial lock configured to block select data modification operations to the reorganized object during said substitution of the reorganized object for the original object.    
   
   
       10 . The software program of  claim 9 , wherein said copying data of the original object to a reorganized object comprises allowing modifications to the data of the original object while collecting records of the modifications.  
   
   
       11 . The software program of  claim 10 , further comprising fifth software instructions for storing the modifications in a redo log.  
   
   
       12 . The software program of  claim 11 , further comprising sixth software instructions capable of applying the modifications from the collected records against the reorganized object.  
   
   
       13 . The software program of  claim 9 , wherein the first software instructions are further capable of removing at least one chained row from the data of the original object.  
   
   
       14 . The software program of  claim 13 , wherein the first software instructions are further capable of accessing a database management system (DBMS) to remove the at least one chained row.  
   
   
       15 . A method of reorganizing a database object, the method comprising: 
 reorganizing an original object by copying data from the original object to a reorganized object;    applying a partial lock to at least one of the original object and the reorganized object, the partial lock blocking data modification operations from modifying the at least one of the original object and the reorganized object while allowing other operations to access the at least one of the original object and the reorganized object; and    substituting the reorganized object for the original object such that the reorganized object remains readable while substituting the reorganized object for the original object.    
   
   
       16 . The method of  claim 15 , wherein the partial lock is applied to the reorganized object during said substitution of the reorganized object for the original object.  
   
   
       17 . The method of  claim 15 , wherein the partial lock is applied to the original object such that additional more-restrictive locks to the original object are not needed during reorganization of the original object.  
   
   
       18 . A reorganization system comprising: 
 means for reorganizing an original object by copying data of the original object to a reorganized object;    means for blocking select data modification operations against the original object while allowing other operations against the original object during reorganization; and    means for blocking select data modification operations against the reorganized object during substitution of the reorganized object for the original object.    
   
   
       19 . The reorganization system of  claim 18 , wherein the other operations include at least one of read-only operations and structural modification operations.  
   
   
       20 . The reorganization system of  claim 18 , wherein the reorganized object remains continuously accessible to one or more clients during the substitution of the reorganized object for the original object.