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Database Development. Indra Budi indra@cs.ui.ac.id. What is differences ?. Logical Data Independence Vs Physical data independence ?. Conceptual Schema. Describes the Meaning of Data in the Universe of Discourse
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Database Development Indra Budi indra@cs.ui.ac.id
What is differences ? • Logical Data Independence Vs Physical data independence ?
Conceptual Schema • Describes the Meaning of Data in the Universe of Discourse • Emphasizes on General, Conceptually Relevant, and Often Time Invariant Structural Aspects of the Universe of Discourse • Excludes the Physical Organization and Access Aspects of the Data
Conceptual Schema • Another Example
External Schema • Describes Parts of the Information in the Conceptual Schema in a form Convenient to a Particular User Group’s View • Derived from the Conceptual Schema
External Schema • Another Example
Internal Schema • Describes How the Information Described in the Conceptual Schema is Physically Represented in a Database to Provide the Overall Best Performance
Internal Schema • Another Example
Building a Database System • Essentially the same as the process for building any other information system, consists of three basic phases: • Requirements phase: a data model is developed • Design phase: the data model is transformed into tables and relationships • Implementation phase: create tables into the DBMS
Requirement Phase • Data model is developed • A data model is a logical representation of the structure of the database • Its very important because design & implementation depend on this phase • If the data model inaccurate, then the result will be waste, aggravation, delays and useless
Example: Data Model • Rectangular are entity & diamonds are relationships • We will discuss this model in detail later…
The Design Phase • The data model transform into tables & relationships • Data properties established type, length, null/not null. • Need for index determined • Constraint, trigger, stored procedure are defined • Figure 1-19 Kroenke
The Implementation Phase • Tables & relationships created • Via SQL • Via Graphical design tool • Stored procedure & trigger are written & tested • Figure 1-20 Kroenke
Application Development • Application development proceeds in parallel with database development
Suggested structure of Report 1 • Introduction • Brief overview of DBMS (name, vendor, version, price (if any), primary user, history of the DBMS, etc) • Description of DBMS features you want to compare and why they are important. • Table comparation • Analysis • Conclusion