Thursday, March 02, 2017

The DB2 12 for z/OS Blog Series – Part 6: Transferring Ownership of Database Objects

When a database object is created it is given a qualified two-part name. This applies to tables, indexes, table spaces, distinct types, functions, stored procedures, and triggers. The first part is the schema name (or the qualifier), which is either implicitly or explicitly specified. The default schema is the authorization ID of the owner of the plan or package. The second part is the name of the object. 

But things can get confusing. When an object is created, an authorization ID is assigned as the owner of the object. This may, or may not, be used as the schema qualifier for the object. The object owner implicitly inherits privileges to reference, maintain and grant privileges to the object. 

Changing the owner of a database object used to be a difficult process. But DB2 12 for z/OS delivers a simple method of transferring the ownership of your database objects: the TRANSFER OWNERSHIP SQL statement. 

The primary purpose for this new feature is to make it easier to manage database objects that are owned by an employee who no longer works for your company. You can use TRANSFER OWNERSHIP to simply switch the ownership of the database objects to another employee. The new owner can be an authorization ID or a role. You can issue the statement interactively, or embed it in an application program. 

The TRANSFER OWNERSHIP statement does not change the schema of the transferred database object. 

In order to transfer ownership of a database object, you must either be the owner of the object or have SECADM authority. The basic syntax of the statement is as follows: 

 TO {USER authorization-name | 
     ROLE role-name} 

Be careful if a package depends on the current owner's privileges. The dependent package will be invalidated unless the current owner is already explicitly granted those privileges from another source prior to the object ownership transfer. For example, after the ownership of a table is transferred and if a dependent package requires the SELECT privilege on that table by the current owner, the dependent package is invalidated unless the current owner has already been explicitly granted the SELECT privilege for that table before its ownership transfer. 

Here is a quick example transferring the ownership of a specific index to a different user, in this case, JOHNDOE. 


No comments: