Github user marmbrus commented on a diff in the pull request:
https://github.com/apache/spark/pull/10844#discussion_r51330387
--- Diff:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala
---
@@ -17,16 +17,34 @@
package org.apache.spark.sql.catalyst.plans
-import org.apache.spark.sql.catalyst.expressions.{Attribute, AttributeSet,
Expression, VirtualColumn}
+import org.apache.spark.sql.catalyst.expressions._
import org.apache.spark.sql.catalyst.trees.TreeNode
import org.apache.spark.sql.types.{DataType, StructType}
-abstract class QueryPlan[PlanType <: TreeNode[PlanType]] extends
TreeNode[PlanType] {
+abstract class QueryPlan[PlanType <: TreeNode[PlanType]]
+ extends TreeNode[PlanType] with PredicateHelper {
self: PlanType =>
def output: Seq[Attribute]
/**
+ * Extracts the relevant per-row constraints from a given child while
removing those that
+ * don't apply anymore.
+ */
+ protected def getRelevantConstraints(child: QueryPlan[PlanType]):
Set[Expression] = {
+ child.constraints.filter(_.references.subsetOf(outputSet))
+ }
+
+ /**
+ * A sequence of expressions that describes the data property of the
output rows of this
+ * operator. For example, if the output of this operator is column `a`,
an example `constraints`
+ * can be `Set(a > 10, a < 20)`.
+ */
+ lazy val constraints: Set[Expression] = validConstraints
+
+ protected def validConstraints: Set[Expression] = Set.empty
--- End diff --
Can we add doc here suggesting the child classes override this method along
with the semantics (i.e. if we go with the suggestion above you are supposed to
output any constraint that might be valid and it will canonicalized and
filtered automatically).
---
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 [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
