What is a Legacy System ? • A sum of money, or a specified article, given to another by will; anything handed down by an ancestor or predecessor. — Oxford English Dictionary • A legacy system is a piece of software that you have inherited, and is valuable to you. • A computer system or application program built on what has since become obsolete technology.
Jan 13, 2019 · Reverse engineering is the process of reading a database schema and producing a data model from that schema. The data model produced is not truly a logical model because entities will be generated for every table, including entities for intersection tables that have no nonkey data and should not appear in a logical model at all.
Reverse Engineering (RE) n Reverse engineering (RE) is the process of reading and producing a data model from a database schema n A reverse engineered (RE) data model: – Provides a basis to begin the database redesign project – Should be carefully reviewed because it almost always has missing information
Example: Oracle database may contain objects likes tables, views, indexes, sequences, triggers, rules, data type, owner, constraints like primary keys, foreign keys, comments etc. You can specify the objects that you are interested to create a model. If you are not interested in triggers, then there is no need for you to check that option.
You can modify/update the reverse engineered model as per your needs. Alignment of tables and relationship on the work place may not be proper and printing out the models will not be in a presentable format. So please align it.