spark-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From cloud-fan <...@git.apache.org>
Subject [GitHub] spark pull request #17330: [SPARK-19993][SQL] Caching logical plans containi...
Date Mon, 20 Mar 2017 06:05:05 GMT
Github user cloud-fan commented on a diff in the pull request:

    https://github.com/apache/spark/pull/17330#discussion_r106838131
  
    --- Diff: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/subquery.scala
---
    @@ -61,6 +63,37 @@ abstract class SubqueryExpression(
       }
     }
     
    +/**
    + * This expression is used to represent any form of subquery expression namely
    + * ListQuery, Exists and ScalarSubquery. This is only used to make sure the
    + * expression equality works properly when LogicalPlan.sameResult is called
    + * on plans containing SubqueryExpression(s). This is only a transient expression
    + * that only lives in the scope of sameResult function call. In other words, analyzer,
    + * optimizer or planner never sees this expression type during transformation of
    + * plans.
    + */
    +case class CanonicalizedSubqueryExpr(expr: SubqueryExpression)
    +  extends UnaryExpression with Unevaluable {
    +  override def dataType: DataType = expr.dataType
    +  override def nullable: Boolean = expr.nullable
    +  override def child: Expression = expr
    +  override def toString: String = s"CanonicalizedSubqueryExpr(${expr.toString})"
    +
    +  // Hashcode is generated conservatively for now i.e it does not include the
    +  // sub query plan. Doing so causes issue when we canonicalize expressions to
    +  // re-order them based on hashcode.
    +  // TODO : improve the hashcode generation by considering the plan info.
    +  override def hashCode(): Int = {
    +    val h = Objects.hashCode(expr.children)
    --- End diff --
    
    can we use `expr.semanticHash` here?


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org


Mime
View raw message