[SPARK-17068][SQL] Make view-usage visible during analysis

## What changes were proposed in this pull request?
This PR adds a field to subquery alias in order to make the usage of views in a resolved `LogicalPlan` more visible (and more understandable).

For example, the following view and query:
```sql
create view constants as select 1 as id union all select 1 union all select 42
select * from constants;
```
...now yields the following analyzed plan:
```
Project [id#39]
+- SubqueryAlias c, `default`.`constants`
   +- Project [gen_attr_0#36 AS id#39]
      +- SubqueryAlias gen_subquery_0
         +- Union
            :- Union
            :  :- Project [1 AS gen_attr_0#36]
            :  :  +- OneRowRelation$
            :  +- Project [1 AS gen_attr_1#37]
            :     +- OneRowRelation$
            +- Project [42 AS gen_attr_2#38]
               +- OneRowRelation$
```
## How was this patch tested?
Added tests for the two code paths in `SessionCatalogSuite` (sql/core) and `HiveMetastoreCatalogSuite` (sql/hive)

Author: Herman van Hovell <hvanhovell@databricks.com>

Closes #14657 from hvanhovell/SPARK-17068.

1 files changed, 13 insertions, 1 deletions

diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveMetastoreCatalogSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveMetastoreCatalogSuite.scala
index 9d72367f43..0477ea4d4c 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveMetastoreCatalogSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveMetastoreCatalogSuite.scala
@@ -23,12 +23,13 @@ import org.apache.spark.sql.{QueryTest, Row, SaveMode}
 import org.apache.spark.sql.catalyst.TableIdentifier
 import org.apache.spark.sql.catalyst.catalog.CatalogTableType
 import org.apache.spark.sql.catalyst.parser.CatalystSqlParser
+import org.apache.spark.sql.catalyst.plans.logical.SubqueryAlias
 import org.apache.spark.sql.hive.test.TestHiveSingleton
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.{ExamplePointUDT, SQLTestUtils}
 import org.apache.spark.sql.types.{DecimalType, IntegerType, StringType, StructField, StructType}
 
-class HiveMetastoreCatalogSuite extends TestHiveSingleton {
+class HiveMetastoreCatalogSuite extends TestHiveSingleton with SQLTestUtils {
   import spark.implicits._
 
   test("struct field should accept underscore in sub-column name") {
@@ -57,6 +58,17 @@ class HiveMetastoreCatalogSuite extends TestHiveSingleton {
     val dataType = StructType((1 to 100).map(field))
     assert(CatalystSqlParser.parseDataType(dataType.catalogString) == dataType)
   }
+
+  test("view relation") {
+    withView("vw1") {
+      spark.sql("create view vw1 as select 1 as id")
+      val plan = spark.sql("select id from vw1").queryExecution.analyzed
+      val aliases = plan.collect {
+        case x @ SubqueryAlias("vw1", _, Some(TableIdentifier("vw1", Some("default")))) => x
+      }
+      assert(aliases.size == 1)
+    }
+  }
 }
 
 class DataSourceWithHiveMetastoreCatalogSuite