Data Model

patinaDB stores a labelled property graph.

Vertices (nodes)

A vertex has:

A stable UUID identity (assigned on creation, baked into the engram log so replays are deterministic).
A primary label plus zero or more secondary labels (multi-label nodes are supported; labels(n) returns all of them).
A set of properties — string keys mapped to typed values.

CREATE (a:Person:Employee {name: 'Ada', born: 1815})

Edges (relationships)

An edge is directed, has exactly one type (a label), connects two vertices, and may carry its own properties:

CREATE (a)-[:KNEW {since: 1833}]->(b)

Edges can be traversed in either direction, and patterns may be left-to-right, right-to-left, or undirected (-[:KNEW]-), in which case both directions are searched.

Property value types

The AttributeValue type covers:

Type	Example literal	Notes
String	`'hello'`	Order-preserving in the value index.
Integer	`42`	64-bit signed.
Float	`3.14`, `1.0e9`, `.5`	64-bit IEEE-754.
Boolean	`true`, `false`	First-class (`AttributeValue::Bool`).
Null	`null`	Drives three-valued logic (see below).
List	`[1, 2, 3]`	Heterogeneous; indexable, sliceable.
Map	`{a: 1, b: 'x'}`	Nested.
Temporal	`date('2026-06-28')`, `datetime(...)`	Date / Time / LocalTime / DateTime / LocalDateTime / Duration.
Path	result of a path pattern	Sequence of nodes and edges.

Three-valued (Kleene) logic

Comparisons and boolean operators follow SQL-style three-valued logic. Any comparison involving null yields Unknown, not true or false:

RETURN 1 = null        // null (Unknown)
RETURN null AND false  // false  (false dominates)
RETURN null OR true    // true   (true dominates)

IS NULL / IS NOT NULL remain strictly two-valued, by specification. In a WHERE filter, Unknown collapses to “not matched”.

Storage internals (informational)

Properties are kept in a label-scoped, order-preserving value index, so a scan over :Person.born never returns :Robot nodes with the same value, and sorted pagination over a property is O(limit) rather than a full scan. Compound indexes over several fields accelerate equality-prefix + sort queries. You normally don’t manage these directly — they are maintained automatically on writes. To declare your own indexes and enforce data integrity, see Constraints and Query Planning; Limitations lists the current DDL gaps.