# guarded Datalog

> fragment of Datalog query language

**Wikidata**: [Q113366400](https://www.wikidata.org/wiki/Q113366400)  
**Source**: https://4ort.xyz/entity/guarded-datalog

## Summary
Guarded Datalog is a fragment of the Datalog query language that serves as a specific subclass of its parent language. It is classified as a declarative programming language. As a subset of Datalog, it inherits the principles of declarative logic programming established by the broader language's inception in 1986.

## Key Facts
- **Classification:** Guarded Datalog is an instance of a declarative programming language.
- **Parent Language:** It is a subclass of Datalog, a declarative logic programming language.
- **Definition:** It is explicitly defined as a fragment of the Datalog query language.
- **Historical Context:** The parent language, Datalog, has an inception date of 1986.
- **Lineage:** It falls under the broad category of declarative programming languages (sitelink count: 4).

## FAQs
### Q: What is guarded Datalog?
A: Guarded Datalog is a specific fragment of the Datalog query language. It is classified as a declarative programming language and a subclass of Datalog.

### Q: What type of programming language is guarded Datalog?
A: It is a declarative programming language. This means it is based on the declarative logic programming paradigm found in its parent language, Datalog.

### Q: How does guarded Datalog relate to standard Datalog?
A: Guarded Datalog is considered a "fragment" and a "subclass" of Datalog. It exists as a specific subset of the broader declarative logic language created in 1986.

## Why It Matters
Guarded Datalog matters because it represents a specialized subset of Datalog, a foundational declarative logic programming language that has been in existence since 1986. In the field of logic programming and database theory, identifying specific "fragments" like guarded Datalog is crucial for defining the boundaries of computability and expressiveness. While Datalog serves as the broad umbrella for logic-based query languages, guarded Datalog provides a focused structure within that system. Its classification as a declarative programming language ensures that it maintains the paradigm of describing *what* the program should accomplish rather than *how* to accomplish it, relying on the logic and constraints defined within the guarded fragment. This specialization allows for targeted application in theoretical computer science and database query optimization.

## Notable For
- Being a defined **fragment** of the Datalog query language.
- Functioning as a **subclass** of the established Datalog system.
- Classification as a **declarative programming language**.
- Existing within the lineage of a language (Datalog) originated in **1986**.

## Body
### Classification and Definition
Guarded Datalog is identified structurally within knowledge bases as a specific entity related to logic programming. Its primary definition is that of a **fragment of the Datalog query language**. In the hierarchy of programming languages, it is listed as an **instance of** a declarative programming language.

### Relationship to Datalog
The entity is strictly defined by its relationship to its parent, **Datalog**.
- **Subclass Of:** Guarded Datalog is a direct subclass of Datalog.
- **Parent Context:** Datalog is defined as a declarative logic programming language.
- **Historical Data:** The parent language, Datalog, traces its inception to the year **1986**.

### Programming Paradigm
Guarded Datalog operates within the declarative paradigm. It shares the "instance of" classification with the broader category of **declarative programming languages**, which focuses on expressing the logic of a computation without describing its control flow.