Vector type in Cypher 5

modules/ROOT/pages/constraints/managing-constraints.adoc

@@ -1070,7 +1070,7 @@ A constraint cannot be created until the index has been dropped.
 | *Property uniqueness constraint*
 |
 ^| ❌
-| 
+|
 
 | *Property existence constraint*
 ^| ❌
@@ -1237,7 +1237,7 @@ Node(9) with label `Movie` required the property `title` to be of type `STRING`,
 | *Property uniqueness constraint*
 |
 ^| ❌
-| 
+|
 
 | *Property existence constraint*
 ^| ❌
@@ -1339,7 +1339,7 @@ RETURN wrote
 | Query
 
 | Node property uniqueness constraint
-a| 
+a|
 [source]
 ----
 MATCH (n1:Label), (n2:Label)
@@ -1348,7 +1348,7 @@ RETURN n1, n2
 ----
 
 | Relationship property uniqueness constraint
-a| 
+a|
 [source]
 ----
 MATCH ()-[r1:REL_TYPE]->(), ()-[r2:REL_TYPE]->()
@@ -1357,7 +1357,7 @@ RETURN r1, r2
 ----
 
 | Node property existence constraint
-a| 
+a|
 [source]
 ----
 MATCH (n:Label)
@@ -1366,7 +1366,7 @@ RETURN n
 ----
 
 | Relationship property existence constraint
-a| 
+a|
 [source]
 ----
 MATCH ()-[r:REL_TYPE]->()
@@ -1375,7 +1375,7 @@ RETURN r
 ----
 
 | Node property type constraint
-a| 
+a|
 [source]
 ----
 MATCH (n:Label)
@@ -1384,7 +1384,7 @@ RETURN n
 ----
 
 | Relationship property type constraint
-a| 
+a|
 [source]
 ----
 MATCH ()-[r:REL_TYPE]->()
@@ -1393,7 +1393,7 @@ RETURN r
 ----
 
 | Node key constraint
-a| 
+a|
 [source]
 ----
 MATCH (n1:Label), (n2:Label)
@@ -1407,7 +1407,7 @@ RETURN n AS node, 'non-existing' AS reason
 ----
 
 | Relationship key constraint
-a| 
+a|
 [source]
 ----
 MATCH ()-[r1:REL_TYPE]->(), ()-[r2:REL_TYPE]->()
@@ -1676,6 +1676,9 @@ label:default-output[] label:new[Introduced in 5.9]
 == DROP CONSTRAINT
 
 Constraints are dropped using the `DROP CONSTRAINT` command.
+It is possible to drop constraints created in a different Cypher version than the one in use.
+For example, although link:https://neo4j.com/docs/cypher-manual/25/values-and-types/vector/[`VECTOR`] property type constraints were added in Cypher 25, such constraints can still be dropped using Cypher 5.
+
 For the full command syntax to drop constraints, see xref:constraints/syntax.adoc#drop-constraint[Syntax -> DROP CONSTRAINT].
 
 [NOTE]
@@ -1764,4 +1767,4 @@ DROP CONSTRAINT missing_constraint_name IF EXISTS
 `DROP CONSTRAINT missing_constraint_name IF EXISTS` has no effect. `missing_constraint_name` does not exist.
 ----
 
-======
+======

modules/ROOT/pages/values-and-types/vector.adoc

@@ -0,0 +1,124 @@
+= Vectors
+:description: Create and store vectors (embeddings) as properties on nodes and relationships, and use them for efficient semantic retrieval with vector indexes and the GenAI plugin.
+:page-role: new-neo4j-2025.10
+
+`VECTOR` values can be stored as xref:indexes/semantic-indexes/vector-indexes.adoc#embeddings[embedding] properties on nodes and relationships, and used for efficient semantic retrieval using xref:indexes/semantic-indexes/vector-indexes.adoc[vector indexes] and the xref:genai-integrations.adoc[GenAI plugin].
+
+[IMPORTANT]
+Although the `VECTOR` type is present in Cypher 5, constructing and comparing vectors is only possible via link:https://neo4j.com/docs/cypher-manual/25/values-and-types/vector/[Cypher 25 features].
+However, vectors can still be inserted in and retrieved from the database with Cypher 5 queries using a link:https://neo4j.com/docs/create-applications/[Neo4j client library] version >= 6.0.
+
+
+[[vector-type]]
+== The vector type
+
+The `VECTOR` type is a fixed-length, ordered collection of numeric values (`INTEGER` or `FLOAT`) stored as a single unit.
+The type of a value is defined by:
+
+- *Dimension* -- The number of values it contains.
+- *Coordinate type* -- The data type of the entries, determining precision and storage size.
+
+.An example `VECTOR` value
+[source]
+----
+vector([1.05, 0.123, 5], 3, FLOAT32)
+----
+
+In this example, `[1.05, 0.123, 5]` is the list of values, `3` its dimension, and `FLOAT32` the data type of the individual entries. +
+Each number in the list can also be seen as a coordinate along one of the vector's dimensions.
+
+
+[[valid-values]]
+=== Valid values
+
+- A `VECTOR` value must have a dimension and a coordinate type.
+- The dimension of a `VECTOR` value must be larger than `0` and less than or equal to `4096`.
+- Vectors cannot contain lists as elements.
+- Supported coordinate types are: +
++
+[options="header",cols="2*<m"]
+|===
+| Default name | Alias
+
+| `FLOAT` | `FLOAT64`
+| `FLOAT32` |
+| `INTEGER` | `INT`, `INT64`, `INTEGER64`, `SIGNED INTEGER`
+| `INTEGER8` | `INT8`
+| `INTEGER16`| `INT16`
+| `INTEGER32` | `INT8`
+
+|===
+
+
+[[drivers-fallback]]
+== Vectors and client libraries (drivers)
+
+Working with vectors via link:{neo4j-docs-base-uri}/create-applications/[Neo4j's client libraries] results in a different behavior depending on the library version.
+
+- *Versions >= 6.0* -- Vectors are fully supported and mapped into client types (see the _Data types_ page of each language manual).
+- *Versions < 6.0* -- Returning a `VECTOR` already present in the database results in a placeholder `MAP` value and a warning.
++
+.Result of returning a `VECTOR` with a driver older than 6.0
+[source]
+----
++----------------------------------------------------------------+
+| n.vector                                                       |
++----------------------------------------------------------------+
+| {originalType: "VECTOR(1, INTEGER64)", reason: "UNKNOWN_TYPE"} |
++----------------------------------------------------------------+
+warn: One or more values returned could not be handled by this version of the driver and were replaced with placeholder map values. Please upgrade your driver!
+03N95 (Neo.ClientNotification.UnknownType)
+----
+
+
+[[type-coercion]]
+== Type coercion
+
+_Coercion_ is the action of forcing entries of a different (implicit) type into a vector with a different coordinate type.
+
+When the coordinate type is the same as the type of the given elements, no coercion is done.
+When the coordinate type differs, coercion may be done or an error may be raised depending on the situation.
+
+*An error is raised* if a value does not fit into the coordinate type.
+If the coordinate type is an `INTEGER` type and all the coordinate values are `INTEGER` values, then an error will be raised if and only if one of the coordinate types does not fit into the size of the specified type.
+The same applies for `FLOAT` vector types: if the elements are all `FLOAT` values then an error will only be raised if one value does not fit into the specified type.
+
+*Coercion (i.e. lossy conversion) is allowed* when:
+
+- The list contains `INTEGER` values and the specified vector type is of a `FLOAT` type.
+Precision will be lost for values at the higher end of the range (see the link:https://docs.oracle.com/javase/specs/jls/se21/html/jls-5.html[Java type specification]), but an error will be raised only if the value were to overflow/underflow. +
+- The list contains `FLOAT` values and the specified type is of an `INTEGER` type.
+Information may be lost, as all values after the decimal point will be truncated, but an error will be raised only if the value were to overflow/underflow. +
+
+
+[[supertypes]]
+== Supertypes
+
+`VECTOR` is a supertype of `VECTOR<TYPE>(DIMENSION)` types.
+The same applies for `VECTOR` types with only a coordinate type or a dimension:
+
+- `VECTOR` with only a defined dimension is a supertype of all `VECTOR` values of that dimension, regardless of the coordinate type.
+For example, `VECTOR(4)` is a supertype of `VECTOR<FLOAT>(4)` and `VECTOR<INT8>(4)`.
+- `VECTOR` with only a defined coordinate type is a supertype of all `VECTOR` values with that coordinate type, regardless of the dimension.
+For example, `VECTOR<INT>` is a supertype of `VECTOR<INT>(3)` and `VECTOR<INT>(1024)`.
+
+All of these supertypes can be used in xref:expressions/predicates/type-predicate-expressions.adoc#type-predicate-vector[type predicate expressions].
+For more information, see:
+
+* xref:values-and-types/ordering-equality-comparison.adoc#ordering-and-comparison[Equality, ordering, and comparison of value types -> Ordering vector types]
+* xref:values-and-types/property-structural-constructed.adoc#vector-type-normalization[Property, structural, and constructed values -> Vector type normalization]
+
+
+[[lists-embeddings-vector-indexes]]
+== Lists, vector embeddings, and vector indexes
+
+`VECTOR` and xref:values-and-types/lists.adoc[`LIST`] values are similar and can both be indexed and searched through using xref:indexes/semantic-indexes/vector-indexes.adoc[vector indexes], but have a few key differences:
+
+- Elements in a `LIST` can be accessed individually, whereas operations on a `VECTOR` must operate on the entire `VECTOR`: it is not possible to access or slice individual elements.
+- Storing vector embeddings as `VECTOR` properties with a defined coordinate type allows them to be stored more efficiently.
+Moreover, reducing a vector's coordinate type (e.g., from `INTEGER16` to `INTEGER8`) downsizes storage requirements and improves performance, provided all values remain within the range supported by the smaller type.
+
+For information about how to store embeddings as `VECTOR` values with the xref:genai-integrations.adoc[GenAI plugin], see:
+
+* xref:genai-integrations.adoc#single-embedding[Generate a single embedding and store it]
+* xref:genai-integrations.adoc#multiple-embeddings[Generate multiple embeddings and store them]