apoc.cypher.mapParallel

存储过程 Apoc Extended 已弃用

apoc.cypher.mapParallel(fragment, params, list-to-parallelize) yield value - 以并行批次执行片段,并将列表段分配给 _

签名

apoc.cypher.mapParallel(fragment :: STRING?, params :: MAP?, list :: LIST? OF ANY?) :: (value :: MAP?)

输入参数

名称 类型 默认

fragment

STRING?

null

params

MAP?

null

list

LIST? OF ANY?

null

输出参数

名称 类型

MAP?

注意:此过程已弃用。对于单次只读操作,请使用 Cypher 并行运行时(parallel runtime)

CYPHER runtime=parallel
CALL {
  MATCH (p:Post)
  WITH
    CASE
      WHEN p.updatedAt IS NULL THEN [p.createdAt]
      ELSE [p.createdAt, p.updatedAt]
    END AS activityDates
  UNWIND activityDates AS activityDate
  RETURN activityDate
  UNION ALL
  MATCH (u:User)
  UNWIND [u.createdAt, u.accessedAt] AS activityDate
  RETURN activityDate
}
RETURN activityDate.year AS year,
       activityDate.month AS month,
       count(*) AS activity
ORDER BY activity DESC, year, month
LIMIT 10

或者,对于写入操作,请使用 IN CONCURRENT TRANSACTIONS

:auto
CALL {
  UNWIND range(0,9) as b
  MATCH (m:Movie { ranking: b }) RETURN m
} IN CONCURRENT TRANSACTIONS
WITH m.ranking as rank
MATCH (n:Movie)
SET n.ranking = 11
RETURN n
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