Enforcing a Cascade Update

What would be needed to enforce a cascade update? One method would be to utilize data dictionary tables and views to backtrack foreign key relations and then apply updates along this path. However, this may be a lengthy process and can be a performance problem. A simpler method would be to implement a table based cascade update. The table would contain the information a procedure would need to update all tables that are dependent upon a main or master table. Therefore, the table would have to contain the master table name, the dependent table(s) and in case we can't duplicate the exact column name across all of the dependent tables, the column to update. The table DDL script in figure 1 meets these requirements.  If required, a fourth column indicating an update order could be added and the cursor in the UPDATE_TABLES procedure detailed later altered to do an ordered retrieve of the information.

CREATE TABLE update_tables
(
                main_table                 VARCHAR2(30) NOT NULL,
                table_name                 VARCHAR2(30) NOT NULL,
                column_name                 VARCHAR2(30) NOT
NULL,
CONSTRAINT pk_update_tables
PRIMARY KEY (main_table,table_name,column_name)
USING INDEX
TABLESPACE tool_indexes)
STORAGE (INITIAL 100K NEXT 100K PCTINCREASE 0)
TABLESPACE tools
/
-- Column definitions are as follows:

SEE CODE DEPOT FOR FULL SCRIPTS

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