spark技术分享ExplodeBase Base Generator Expression
ExplodeBase is the base class for Explode and PosExplode generator expressions.
ExplodeBase is a unary expression and Generator with CodegenFallback.
Explode Generator Unary Expression
Explode is a unary expression that produces a sequence of records for each value in the array or map.
Explode is a result of executing explode function (in SQL and functions)
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scala> sql("SELECT explode(array(10,20))").explain == Physical Plan == Generate explode([10,20]), false, false, [col#68] +- Scan OneRowRelation[] scala> sql("SELECT explode(array(10,20))").queryExecution.optimizedPlan.expressions(0) res18: org.apache.spark.sql.catalyst.expressions.Expression = explode([10,20]) val arrayDF = Seq(Array(0,1)).toDF("array") scala> arrayDF.withColumn("num", explode('array)).explain == Physical Plan == Generate explode(array#93), true, false, [array#93, num#102] +- LocalTableScan [array#93] |
