[SPARK-14137] [SPARK-14150] [SQL] Infer IsNotNull constraints from non-nullable attributes

## What changes were proposed in this pull request?

This PR adds support for automatically inferring `IsNotNull` constraints from any non-nullable attributes that are part of an operator's output. This also fixes the issue that causes the optimizer to hit the maximum number of iterations for certain queries in https://github.com/apache/spark/pull/11828.

## How was this patch tested?

Unit test in `ConstraintPropagationSuite`

Author: Sameer Agarwal <sameer@databricks.com>

Closes #11953 from sameeragarwal/infer-isnotnull.

1 files changed, 9 insertions, 0 deletions

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/ConstraintPropagationSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/ConstraintPropagationSuite.scala
index f3ab026192..e5063599a3 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/ConstraintPropagationSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/ConstraintPropagationSuite.scala
@@ -23,6 +23,7 @@ import org.apache.spark.sql.catalyst.dsl.expressions._
 import org.apache.spark.sql.catalyst.dsl.plans._
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.plans.logical._
+import org.apache.spark.sql.types.{IntegerType, StringType}
 
 class ConstraintPropagationSuite extends SparkFunSuite {
 
@@ -217,4 +218,12 @@ class ConstraintPropagationSuite extends SparkFunSuite {
         IsNotNull(resolveColumn(tr, "a")),
         IsNotNull(resolveColumn(tr, "b")))))
   }
+
+  test("infer IsNotNull constraints from non-nullable attributes") {
+    val tr = LocalRelation('a.int, AttributeReference("b", IntegerType, nullable = false)(),
+      AttributeReference("c", StringType, nullable = false)())
+
+    verifyConstraints(tr.analyze.constraints,
+      ExpressionSet(Seq(IsNotNull(resolveColumn(tr, "b")), IsNotNull(resolveColumn(tr, "c")))))
+  }
 }