Tuesday, December 15, 2009

How to use Oracle's Metadata package for impact analysis

By: Milind Zodge

Overview

Business is always changing and you have to make some changes based on the business requirement.

Before doing any change you want to perform an impact analysis. Most of the data modeling tools have provision to do it. I am focusing in the article how you perform this task if you don't have a tool.

Details

Consider a case, we have Oracle database and wants to alter a column width and would like to see wherever this column is used/ referenced.
We can use Oracle's metadata package as indicated below
SET pagesize 0

SET long 90000

SET feedback off

SET echo off
SELECT DBMS_METADATA.GET_DDL('TABLE',ut.table_name)

FROM USER_TABLES ut;

This will give DDL scripts for all the tables. Now you can use any text tool like Notepad to search for the required column and find out the references.

Conclusion

There are various ways to do it. This is one of them. This will help you determining the impact exposure.

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