Database Concepts

Schema and Non-schema objects

An entity is the smallest unity containing a meaningful set of data. Examples are rows, columns, and tables.

A table is the base unit of database to store data, formatted with columns and rows

\n Schema is a set of rules specifying the structure and behavior of data in a database. User is the individual who uses the database system to store and process data.

Has a real table filled by a SQL query The real table is truncated and refilled with a specific time frequency.

Structured Query Language

Relational Database Management System

A connection between two tables.

A virtual table that provides access to a subset of columns or some restricted rows from one or more tables. They act like a real table, but do not physically use any space for the returning data.

Complied PL/SQL program units stored in the database and executed with a specific event like an insert, update, delete, or create, etc. They are used for performing other operations "BEFORE", "ON" or "AFTER" the main operation.

Is an alternative name or an alias for the database objects. By using these you can query other user's objects without writing its schema name

Database objects which generate unique integers and generally used for primary key values (unique values for a row).

The schema objects that are complied and stored in the database and consist of logically grouped SQL and PL/SQL codes, variables, cursors, etc. in it to perform one or more than one operations by using its functions or procedures.

A place that we store an organized collection of data.

Are the connections between two physical database servers.

Constraints are the rules for restricting invalid data entries into tables.

This type of DBMS uses the parent-child relationship for storing the data.