These operators are used in queries that update the graph.
Constraint Operation
Creates a constraint on a (label,property) pair.
The following query will create a unique constraint on the name property of nodes with the Country label.
Query
CREATE CONSTRAINT ON (c:Country) ASSERT c.name IS UNIQUE
Query Plan
+-------------------------+ | Operator | +-------------------------+ | +CreateUniqueConstraint | +-------------------------+ Total database accesses: ?
Empty Result
Eagerly loads everything coming in to the EmptyResult operator and discards it.
Query
CREATE (:Person)
Query Plan
+-----------------+----------------+------+---------+-----------+ | Operator | Estimated Rows | Rows | DB Hits | Variables | +-----------------+----------------+------+---------+-----------+ | +ProduceResults | 1 | 0 | 0 | | | | +----------------+------+---------+-----------+ | +EmptyResult | | 0 | 0 | | | | +----------------+------+---------+-----------+ | +CreateNode | 1 | 1 | 2 | anon[8] | +-----------------+----------------+------+---------+-----------+ Total database accesses: 2
Update Graph
Applies updates to the graph.
Query
CYPHER planner=rule
CREATE (:Person { name: "Alistair" })
Query Plan
+--------------+------+---------+-----------+------------+ | Operator | Rows | DB Hits | Variables | Other | +--------------+------+---------+-----------+------------+ | +EmptyResult | 0 | 0 | | | | | +------+---------+-----------+------------+ | +UpdateGraph | 1 | 4 | anon[7] | CreateNode | +--------------+------+---------+-----------+------------+ Total database accesses: 4
Merge Into
When both the start and end node have already been found, merge-into is used to find all connecting relationships or creating a new relationship between the two nodes.
Query
CYPHER planner=rule
MATCH (p:Person { name: "me" }),(f:Person { name: "Andres" })
MERGE (p)-[:FRIENDS_WITH]->(f)
Query Plan
+--------------+------+---------+------------------+--------------------------------+
| Operator | Rows | DB Hits | Variables | Other |
+--------------+------+---------+------------------+--------------------------------+
| +EmptyResult | 0 | 0 | | |
| | +------+---------+------------------+--------------------------------+
| +Merge(Into) | 1 | 5 | anon[68] -- f, p | (p)-[:FRIENDS_WITH]->(f) |
| | +------+---------+------------------+--------------------------------+
| +SchemaIndex | 1 | 2 | f -- p | { AUTOSTRING1}; :Person(name) |
| | +------+---------+------------------+--------------------------------+
| +SchemaIndex | 1 | 2 | p | { AUTOSTRING0}; :Person(name) |
+--------------+------+---------+------------------+--------------------------------+
Total database accesses: 9