System Built-In
In Ultipa, each node has two built-in unique identifiers: _id and _uuid.
| Unique Identifier | Value Type | Description |
|---|---|---|
_id |
STRING |
A string-type unique identifier with a length of up to 128 bytes. Its value can be either automatically generated by the system or manually assigned. |
_uuid |
UINT64 |
A numeric unique identifier with values generated by the system. |
Each edge has a built-in unique identifier: _uuid. Meanwhile, each edge connects a source node to a destination node, its _from/_to and _from_uuid/_to_uuid identify its two end nodes.
| Unique Identifier | Value Type | Description |
|---|---|---|
_uuid |
UINT64 |
A numeric unique identifier with values generated by the system. |
_from |
STRING |
The _id of the source node of an edge. |
_to |
STRING |
The _id of the destination node of an edge. |
_from_uuid |
UINT64 |
The _uuid of the source node of an edge. |
_to_uuid |
UINT64 |
The _uuid of the destination node of an edge. |
User-Defined
You can specify the EDGE KEY constraint on one or more edge properties to serve as the unique identifiers for edges. Learn more about the EDGE KEY constraint.