> For the complete documentation index, see [llms.txt](https://www.pranaypourkar.co.in/the-programmers-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.pranaypourkar.co.in/the-programmers-guide/database/sql-databases/terminology.md). # Terminology ### Data Data is a collection of a distinct small unit of information. ### Database The database is a collection of inter-related data which is used to retrieve, insert, update and delete the data efficiently. It is also used to organize the data in the form of a table, schema, views, and reports, etc. For example, the employee database organizes the data about the employee, department, etc. ### **Table** A structured set of data elements, organized in rows and columns. Tables are the primary structure in a relational database. ### **Row** Also known as a record, it represents a single, complete set of related data in a table. ### **Column** Also known as a field, it represents a single attribute of data in a table. ### **Primary Key** A column or set of columns that uniquely identifies each row in a table. It ensures data integrity and provides a way to reference individual records. ### **Foreign Key** A column or set of columns in one table that references the primary key in another table. It establishes a relationship between the two tables. ### **Index** An optional structure associated with a table to improve the speed of data retrieval. Indexes are created on columns to quickly locate rows in a table. ### **Query** A request for data or information from a database. SQL queries are used to retrieve, insert, update, or delete data from tables ### **Normalization** A process of organizing data in a database to reduce redundancy and dependency. It involves dividing large tables into smaller, related tables and defining relationships between them. ### **Transaction** A single unit of work performed within a database management system. It can consist of one or more SQL statements that are executed as a single operation. ### **View** A virtual table generated from the result of a SQL query. Views do not store data themselves but provide a way to present data stored in tables in a customized format. ### **Stored Procedure** A pre-compiled collection of SQL statements that are stored and executed on the database server. Stored procedures can accept input parameters and return multiple values. ### **Trigger** A special type of stored procedure that is automatically executed or fired in response to specific events, such as data manipulation (insert, update, delete) on a table. ### **Clauses** Components within a statement that define specific actions (e.g., SELECT clause in a SELECT statement). ### Operator A special keyword used to join or change clauses within a WHERE clause. Also known as logical operators. Eg. OR, AND, IN etc ### **Degree** Represents the number of columns in a table. It indicates the complexity of each record (row) in the table. A higher degree (more columns) can provide richer data but also increases storage requirements and complexity of managing the data.\ **Example**: A Customers table with columns for CustomerID, FirstName, LastName, Email, and PhoneNumber has a degree of 5. ### **Cardinality** Represents the number of rows in a table. It indicates the overall size or volume of data stored in the table. A higher cardinality (more rows) can lead to larger storage needs and potentially slower query performance for retrieving data.\ **Example**: A Customers table with information for 1000 customers has a cardinality of 1000. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://www.pranaypourkar.co.in/the-programmers-guide/database/sql-databases/terminology.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.