Data modeling is the process of analyzing and defining all the different data your business collects and produces, as well as the relationships between those bits of data. The goal is to illustrate the types of data used and stored within the system, the relationships among these data types, the ways the data can be grouped and organized and its formats and attributes.
Database/Data Model
A database/data model is a mathematical formalism with a notation for describing data structures and a set of operations used to manipulate and validate that data. For example, a data model might specify that a customer record contains a custom name and credit card number and a product record contains a product code and price and that there is a one-to-many relation between a customer and a product.
Relational Data Model
| A relational data model is a data model introduced by E. F. Codd in 1970, particularly well suited for business data management. In this model, data are organized in tables. The set of names of the columns is called the “schema” of the table. The data can be manipulated using a relational algebra. |
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Relational Algebra
Relational algebra is a family of algebra with a well-founded semantics used for modeling the data stored in relational databases, and defining queries on it. The main operations of the relational algebra are the set operations (such as union, intersection, and Cartesian product), selection (keeping only some lines of a table) and the projection (keeping only some columns).
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“Never let your sense of morals prevent you from doing what is right.” ― Isaac Asimov, Foundation |