Do the same for functions and partitions

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/TableIdentifier.scala

@@ -18,7 +18,8 @@
 package org.apache.spark.sql.catalyst
 
 /**
- * Identifies a `table` in `database`.  If `database` is not defined, the current database is used.
+ * Identifies a table in a database.
+ * If `database` is not defined, the current database is used.
  */
 private[sql] case class TableIdentifier(table: String, database: Option[String]) {
   def this(table: String) = this(table, None)
@@ -33,3 +34,22 @@ private[sql] case class TableIdentifier(table: String, database: Option[String])
 private[sql] object TableIdentifier {
   def apply(tableName: String): TableIdentifier = new TableIdentifier(tableName)
 }
+
+/**
+ * Identifies a function in a database.
+ * If `database` is not defined, the current database is used.
+ */
+// TODO: reuse some code with TableIdentifier.
+private[sql] case class FunctionIdentifier(name: String, database: Option[String]) {
+  def this(name: String) = this(name, None)
+
+  override def toString: String = quotedString
+
+  def quotedString: String = database.map(db => s"`$db`.`$name`").getOrElse(s"`$name`")
+
+  def unquotedString: String = database.map(db => s"$db.$name").getOrElse(name)
+}
+
+private[sql] object FunctionIdentifier {
+  def apply(funcName: String): FunctionIdentifier = new FunctionIdentifier(funcName)
+}

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala

@@ -19,7 +19,7 @@ package org.apache.spark.sql.catalyst.catalog
 
 import java.util.concurrent.ConcurrentHashMap
 
-import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
 import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
 
 
@@ -64,6 +64,8 @@ abstract class SessionCatalog(catalog: ExternalCatalog) {
   // sessions as their metadata is persisted in the underlying catalog.
   // ----------------------------------------------------------------------------
 
+  // Methods that interact with metastore tables only.
+
   /**
    * Create a metastore table in the database specified in `tableDefinition`.
    * If no such table is specified, create it in the current database.
@@ -84,7 +86,9 @@ abstract class SessionCatalog(catalog: ExternalCatalog) {
   /**
    * Retrieve the metadata of an existing metastore table.
    */
-  def getTableMetadata(name: TableIdentifier): CatalogTable
+  def getTable(name: TableIdentifier): CatalogTable
+
+  // Methods that interact with temporary tables and metastore tables.
 
   /**
    * Create a temporary table.
@@ -140,24 +144,27 @@ abstract class SessionCatalog(catalog: ExternalCatalog) {
    */
   def listTables(currentDb: String, pattern: String): Seq[TableIdentifier]
 
-  // --------------------------------------------------------------------------
+  // ----------------------------------------------------------------------------
   // Partitions
+  // ----------------------------------------------------------------------------
   // All methods in this category interact directly with the underlying catalog.
-  // --------------------------------------------------------------------------
-  // TODO: We need to figure out how these methods interact with our data source tables.
-  // For data source tables, we do not store values of partitioning columns in the metastore.
-  // For now, partition values of a data source table will be automatically discovered
-  // when we load the table.
+  // These methods are concerned with only metastore tables.
+  // ----------------------------------------------------------------------------
+
+  // TODO: We need to figure out how these methods interact with our data source
+  // tables. For such tables, we do not store values of partitioning columns in
+  // the metastore. For now, partition values of a data source table will be
+  // automatically discovered when we load the table.
 
   def createPartitions(
-      db: String,
-      table: String,
+      currentDb: String,
+      tableName: TableIdentifier,
       parts: Seq[CatalogTablePartition],
       ignoreIfExists: Boolean): Unit
 
   def dropPartitions(
-      db: String,
-      table: String,
+      currentDb: String,
+      tableName: TableIdentifier,
       parts: Seq[TablePartitionSpec],
       ignoreIfNotExists: Boolean): Unit
 
@@ -166,8 +173,8 @@ abstract class SessionCatalog(catalog: ExternalCatalog) {
    * This assumes index i of `specs` corresponds to index i of `newSpecs`.
    */
   def renamePartitions(
-      db: String,
-      table: String,
+      currentDb: String,
+      tableName: TableIdentifier,
       specs: Seq[TablePartitionSpec],
       newSpecs: Seq[TablePartitionSpec]): Unit
 
@@ -179,69 +186,59 @@ abstract class SessionCatalog(catalog: ExternalCatalog) {
    * this becomes a no-op.
    */
   def alterPartitions(
-      db: String,
-      table: String,
+      currentDb: String,
+      tableName: TableIdentifier,
       parts: Seq[CatalogTablePartition]): Unit
 
-  def getPartition(db: String, table: String, spec: TablePartitionSpec): CatalogTablePartition
+  def getPartition(
+      currentDb: String,
+      tableName: TableIdentifier,
+      spec: TablePartitionSpec): CatalogTablePartition
 
-  def listPartitions(db: String, table: String): Seq[CatalogTablePartition]
+  def listPartitions(
+      currentDb: String,
+      tableName: TableIdentifier): Seq[CatalogTablePartition]
 
-  // --------------------------------------------------------------------------
+  // ----------------------------------------------------------------------------
   // Functions
-  // --------------------------------------------------------------------------
+  // ----------------------------------------------------------------------------
+  // There are two kinds of functions, temporary functions and metastore
+  // functions (permanent UDFs). Temporary functions are isolated across
+  // sessions. Metastore functions can be used across multiple sessions as
+  // their metadata is persisted in the underlying catalog.
+  // ----------------------------------------------------------------------------
+
+  // Methods that interact with metastore functions only.
 
-  // --------------------------------------------------------------------------
-  // Functions: Methods for metastore functions (permanent UDFs).
-  // --------------------------------------------------------------------------
+  def createFunction(currentDb: String, funcDefinition: CatalogFunction): Unit
 
-  def createFunction(db: String, funcDefinition: CatalogFunction): Unit
+  def dropFunction(currentDb: String, funcName: FunctionIdentifier): Unit
 
   /**
-   * Drops a permanent function with the given name from the given database.
+   * Alter a function whose name that matches the one specified in `funcDefinition`,
+   * assuming the function exists.
+   *
+   * Note: If the underlying implementation does not support altering a certain field,
+   * this becomes a no-op.
    */
-  def dropFunction(db: String, funcName: String): Unit
+  def alterFunction(currentDb: String, funcDefinition: CatalogFunction): Unit
 
-  // --------------------------------------------------------------------------
-  // Functions: Methods for metastore functions (permanent UDFs) or temp functions.
-  // --------------------------------------------------------------------------
+  // Methods that interact with temporary functions and metastore functions.
 
   def createTempFunction(funcDefinition: CatalogFunction): Unit
 
-  /**
-   * Drops a temporary function with the given name.
-   */
   // TODO: The reason that we distinguish dropFunction and dropTempFunction is that
   // Hive has DROP FUNCTION and DROP TEMPORARY FUNCTION. We may want to consolidate
   // dropFunction and dropTempFunction.
   def dropTempFunction(funcName: String): Unit
 
   def renameFunction(
-      specifiedDB: Option[String],
-      currentDB: String,
-      oldName: String,
-      newName: String): Unit
+      currentDb: String,
+      oldName: FunctionIdentifier,
+      newName: FunctionIdentifier): Unit
 
-  /**
-   * Alter a function whose name that matches the one specified in `funcDefinition`,
-   * assuming the function exists.
-   *
-   * Note: If the underlying implementation does not support altering a certain field,
-   * this becomes a no-op.
-   */
-  def alterFunction(
-      specifiedDB: Option[String],
-      currentDB: String,
-      funcDefinition: CatalogFunction): Unit
-
-  def getFunction(
-      specifiedDB: Option[String],
-      currentDB: String,
-      funcName: String): CatalogFunction
-
-  def listFunctions(
-      specifiedDB: Option[String],
-      currentDB: String,
-      pattern: String): Seq[String]
+  def getFunction(currentDb: String, funcIdentifier: FunctionIdentifier): CatalogFunction
+
+  def listFunctions(currentDb: String, pattern: String): Seq[FunctionIdentifier]
 
 }

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala

@@ -167,6 +167,7 @@ abstract class ExternalCatalog {
  * @param name name of the function
  * @param className fully qualified class name, e.g. "org.apache.spark.util.MyFunc"
  */
+// TODO: use FunctionIdentifier here.
 case class CatalogFunction(name: String, className: String)