13.4. apoc.periodic.commit

Especially for graph processing it is useful to run a query repeatedly in separate transactions until it doesn’t process and generates any results anymore. So you can iterate in batches over elements that don’t fulfill a condition and update them so that they do afterwards.

as a safety net your statement used inside apoc.periodic.commit must contain a LIMIT clause.

The query is executed repatedly in separate transactions until it returns 0.

call apoc.periodic.commit("
match (user:User) WHERE exists( user.city )
with user limit {limit}
MERGE (city:City {name:user.city})
MERGE (user)-[:LIVES_IN]->(city)
REMOVE user.city
RETURN count(*)
|2000000|200       |