Fundamentals

Fundamentals#

ArchiTXT represents a database instances as a hierarchical tree structure called the meta-model. This meta-model acts as an intermediary, database-agnostic representation. It allows flexible transformation from/to various database models such as :

  • Relational databases

  • Document-oriented databases

  • Graph databases (RDF, Property Graph)

  • Tabular formats (CSV, TSV, etc.)

  • XML

Instance Representation#

A database instance is a set of architxt.tree.Tree organised into a forest. Each node in these trees represents a fundamental database concept. The key components are:

  • Entity: A fundamental data unit representing a name-value couple such as attributes.

  • Group: A collection of Entities that share a semantic relationship.

  • Relation: A connection between two Groups.

  • Collection: A set of equivalent Groups or Relations.

Below is a visual representation of an instance in ArchiTXT:

Schema Definition#

Given an instance structured as a forest, a architxt.schema.Schema is a grammar. This grammar recognises a subset of trees that compose a valid database instance.

The following, is the minimal schema that recognises the above instance:

ROOT   ::= REL1 | GROUP1 | GROUP2
REL1   ::= GROUP1 GROUP2
GROUP1 ::= ENT1 ENT2
GROUP2 ::= ENT3
ENT1   ::= <data>
ENT2   ::= <data>
ENT3   ::= <data>
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