DBM #00: Lecture Schedule

Mod. 1: 16 lectures
Mod. 2: 24 lectures
Mod. 3: 3 lectures
Mod. 4: 4 lectures
Mod. 5: 19 lectures
Mod. 6: 15 lectures

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DBMS #05: Data Independence

The three levels of schema provided by the DBMS are: 1) Internal/ physical schema, which describes how the data is actually stored. 2) Conceptual/ logical schema, which describes what data is present in the database (and its meaning), and 3) External schema, which describes the use of the data. This is derived from the conceptual schema and not physically stored in the database. Physical data independence is a measure of how much a physical schema can be changed without affecting the logical schema. Similarly, we can define logical data independence. Logical data independence is harder to achieve, and hence changes are more possible to the external schema when there are changes in conceptual schema.
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DBMS #01: Introduction to DBMS

Data: raw facts; becomes information when it becomes meaningful. Database: it is a large collection of related data. It models some real-world organization (e.g., a school), with entities (e.g., students, courses) and relationships (e.g., student 'a' takes course 'y'). It represents some aspect of the real world. There are various data models that are used to represent data in a database. For instance, the school database can be modelled in a tabular fashion, rather than a graphical fashion. DBMS is a software that manages some database. It is an interface between a user and a database. It also enables to abstract data representation and storage, thereby insulating the application code from such specifications. Data retrieval is also efficient. It also offers concurrent access and crash recovery. A data model is a set of rules or conventions to represent, store and manage the data. Models can be useful to examine or analyze some aspect of the real world. To design a d...
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DBMS #04: Joins, Decomposition and Normalization

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