From 59c60a6d2d2d59f1a7656fd197442934fbc06a11 Mon Sep 17 00:00:00 2001
From: Joshi <rekhajoshm@gmail.com>
Date: Tue, 5 Apr 2016 14:37:45 -0700
Subject: [PATCH 1/2] SessionCatalog function/database existence checks,
 metadata

---
 .../sql/catalyst/catalog/SessionCatalog.scala | 28 +++++++++----------
 .../catalog/SessionCatalogSuite.scala         |  8 +++---
 2 files changed, 17 insertions(+), 19 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 c08ffbb235e41..7f6b002a90405 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
@@ -84,19 +84,25 @@ class SessionCatalog(
   // ----------------------------------------------------------------------------
 
   def createDatabase(dbDefinition: CatalogDatabase, ignoreIfExists: Boolean): Unit = {
-    externalCatalog.createDatabase(dbDefinition, ignoreIfExists)
+    if (!databaseExists(dbDefinition.name)) {
+      externalCatalog.createDatabase(dbDefinition, ignoreIfExists)
+    }
   }
 
   def dropDatabase(db: String, ignoreIfNotExists: Boolean, cascade: Boolean): Unit = {
-    externalCatalog.dropDatabase(db, ignoreIfNotExists, cascade)
+    if (databaseExists(db)) {
+      externalCatalog.dropDatabase(db, ignoreIfNotExists, cascade)
+    }
   }
 
   def alterDatabase(dbDefinition: CatalogDatabase): Unit = {
-    externalCatalog.alterDatabase(dbDefinition)
+    if (databaseExists(dbDefinition.name)) {
+      externalCatalog.alterDatabase(dbDefinition)
+    }
   }
 
   def getDatabase(db: String): CatalogDatabase = {
-    externalCatalog.getDatabase(db)
+      externalCatalog.getDatabase(db)
   }
 
   def databaseExists(db: String): Boolean = {
@@ -460,8 +466,7 @@ class SessionCatalog(
    * If a database is specified in `name`, this will return the function in that database.
    * If no database is specified, this will return the function in the current database.
    */
-  // TODO: have a better name. This method is actually for fetching the metadata of a function.
-  def getFunction(name: FunctionIdentifier): CatalogFunction = {
+  def getMetadataOfFunction(name: FunctionIdentifier): CatalogFunction = {
     val db = name.database.getOrElse(currentDb)
     externalCatalog.getFunction(db, name.funcName)
   }
@@ -474,15 +479,8 @@ class SessionCatalog(
       // This function exists in the FunctionRegistry.
       true
     } else {
-      // Need to check if this function exists in the metastore.
-      try {
-        // TODO: It's better to ask external catalog if this function exists.
-        // So, we can avoid of having this hacky try/catch block.
-        getFunction(name) != null
-      } catch {
-        case _: NoSuchFunctionException => false
-        case _: AnalysisException => false // HiveExternalCatalog wraps all exceptions with it.
-      }
+      val db = name.database.getOrElse(currentDb)
+      externalCatalog.listFunctions(db,name.unquotedString).size > 0
     }
   }
 
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala
index 4d56d001b3e7d..a476521d9eb72 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalogSuite.scala
@@ -753,19 +753,19 @@ class SessionCatalogSuite extends SparkFunSuite {
     val expected =
       CatalogFunction(FunctionIdentifier("func1", Some("db2")), funcClass,
       Seq.empty[(String, String)])
-    assert(catalog.getFunction(FunctionIdentifier("func1", Some("db2"))) == expected)
+    assert(catalog.getMetadataOfFunction(FunctionIdentifier("func1", Some("db2"))) == expected)
     // Get function without explicitly specifying database
     catalog.setCurrentDatabase("db2")
-    assert(catalog.getFunction(FunctionIdentifier("func1")) == expected)
+    assert(catalog.getMetadataOfFunction(FunctionIdentifier("func1")) == expected)
   }
 
   test("get function when database/function does not exist") {
     val catalog = new SessionCatalog(newBasicCatalog())
     intercept[AnalysisException] {
-      catalog.getFunction(FunctionIdentifier("func1", Some("does_not_exist")))
+      catalog.getMetadataOfFunction(FunctionIdentifier("func1", Some("does_not_exist")))
     }
     intercept[AnalysisException] {
-      catalog.getFunction(FunctionIdentifier("does_not_exist", Some("db2")))
+      catalog.getMetadataOfFunction(FunctionIdentifier("does_not_exist", Some("db2")))
     }
   }
 

From e040216efc19f111371883989f8df5b34dc032db Mon Sep 17 00:00:00 2001
From: Joshi <rekhajoshm@gmail.com>
Date: Tue, 5 Apr 2016 14:40:13 -0700
Subject: [PATCH 2/2] SessionCatalog function/database existence checks,
 metadata

---
 .../org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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 7f6b002a90405..6224d0bc61b61 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
@@ -102,7 +102,7 @@ class SessionCatalog(
   }
 
   def getDatabase(db: String): CatalogDatabase = {
-      externalCatalog.getDatabase(db)
+    externalCatalog.getDatabase(db)
   }
 
   def databaseExists(db: String): Boolean = {