Managing data conversion for user-defined data types within a database management system

Abstract

Managing data conversion for user-defined data types within a DBMS. A custom data type definition and one or more converters are stored within a database management system. Each converter can convert instances of the custom data type between a binary format and a programming language format. The database management system receives a request for a custom data type instance in a specified programming language format. A converter among the one or more converters converts the custom data type instance expressed in the binary format into a custom data type instance expressed in the specified programming language format, using a custom data type definition from the database management system. The request is responded to with the converted custom data type instance in the specified programming language format.

1 . A method for managing data conversion for a custom data type in a database management system, comprising:
 storing a custom data type definition and one or more converters within a database management system, each converter being operable to convert instances of the custom data type between a binary format and a programming language format;   receiving, by the database management system, a request for a custom data type instance in a specified programming language format;   converting, by a converter among the one or more converters, the custom data type instance expressed in the binary format into a custom data type instance expressed in the specified programming language format using a custom data type definition from the database management system; and   responding to the request with the converted custom data type instance in the specified programming language format.   
     
     
         2 . The method of  claim 1 , wherein the custom data type definition is a user defined data type definition. 
     
     
         3 . The method of  claim 2 , wherein the user defined type is a compound user type made up from built-in database types. 
     
     
         4 . The method of  claim 1 , further comprising:
 providing a programming language interface for each of the one or more converters to allow calls to the instances of the custom data type.   
     
     
         5 . The method of  claim 1 , wherein the custom data type definition and the one or more converters are stored in a catalog of the database management system. 
     
     
         6 . The method of  claim 5 , further comprising:
 determining whether the database management system contains any custom data type definitions by querying the catalog's metadata.   
     
     
         7 . The method of  claim 1 , further comprising storing a version for the custom data type definition.