DBMS
Inside the DBMS: Components and How a Query Flows
A DBMS is built from a query processor, a storage manager, a transaction manager and a recovery manager. Following one query through all of them is th...
DBMS
A complete DBMS path: database fundamentals, architecture, data models, the ER model, the relational model, relational algebra, functional dependencies, normalisation, transactions, concurrency control, recovery, storage, indexing, query processing, distributed databases, NoSQL, security, administration, performance and exam preparation.
59 notes in 21 topics
Topics in DBMS
DBMS Fundamentals 9
Database Architecture 4
Data Models 5
ER Model 9
ER Design Projects 5
Relational Model 6
Relational Algebra 6
Functional Dependencies 5
Normalisation 9
Transactions 0
Concurrency Control 1
Recovery 0
Storage and File Organisation 0
Indexing 0
Query Processing 0
Distributed Databases 0
NoSQL and Modern Databases 0
Database Security 0
Database Administration 0
Database Performance 0
Practice and Exams 0
Notes
DBMS
What a Data Model Is
A data model is the set of concepts used to describe data, relationships, semantics and constraints. Models are grouped as high level, representationa...
DBMS
Hierarchical and Network Data Models
The hierarchical model arranges records in a tree with one parent each; the network model allows many parents through a graph of sets. Both used physi...
DBMS
The Relational Model as a Data Model
The relational model stores everything in tables and connects them by matching values rather than pointers. That one decision delivers declarative que...
DBMS
Object Oriented and Object Relational Models
The object oriented model stores objects with identity, state and behaviour. The object relational model adds those ideas to a relational core, which...
DBMS
Comparing Data Models and Choosing One
A single comparison of hierarchical, network, relational, object oriented, object relational and NoSQL models, plus a practical method for choosing a...
DBMS
Entities, Entity Sets and Entity Types
An entity is a distinguishable thing the database stores facts about, an entity type is its definition, and an entity set is the collection of entitie...
DBMS
Types of Attributes in the ER Model
Attributes are simple or composite, single valued or multivalued, stored or derived, and may be complex, key or null valued. Each type converts into t...
DBMS
Keys in the ER Model
A key attribute distinguishes one entity from another. Understanding super keys, candidate keys, primary keys and partial keys at design time prevents...
DBMS
Relationships, Relationship Sets and Degree
A relationship is an association among entities. Relationship types have a degree, may carry their own attributes, and may connect an entity type to i...
DBMS
Cardinality and Participation Constraints
Cardinality says how many entities on one side may relate to entities on the other; participation says whether every entity must take part. Together t...
DBMS
Strong and Weak Entities
A weak entity has no key of its own and can only be identified through an owner entity. It is drawn with a double rectangle, joined by an identifying...