[SPARK-19029][SQL] Remove databaseName from SimpleCatalogRelation

### What changes were proposed in this pull request?
Remove useless `databaseName ` from `SimpleCatalogRelation`.

### How was this patch tested?
Existing test cases.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #16438 from gatorsmile/removeDBFromSimpleCatalogRelation.

2 files changed, 1 insertions, 6 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
index 741ed05b63..2060d535b0 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
@@ -573,7 +573,7 @@ class SessionCatalog(
         val view = Option(metadata.tableType).collect {
           case CatalogTableType.VIEW => name
         }
-        SubqueryAlias(relationAlias, SimpleCatalogRelation(db, metadata), view)
+        SubqueryAlias(relationAlias, SimpleCatalogRelation(metadata), view)
       } else {
         SubqueryAlias(relationAlias, tempTables(table), Option(name))
       }
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
index 24d75ab02c..b402bd2d6c 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
@@ -318,7 +318,6 @@ trait CatalogRelation {
  * Note that in the future we should consolidate this and HiveCatalogRelation.
  */
 case class SimpleCatalogRelation(
-    databaseName: String,
     metadata: CatalogTable)
   extends LeafNode with CatalogRelation {
 
@@ -335,8 +334,4 @@ case class SimpleCatalogRelation(
       }
     dataCols ++ partCols
   }
-
-  require(
-    metadata.identifier.database == Some(databaseName),
-    "provided database does not match the one specified in the table definition")
 }