[SPARK-36914][SQL] Implement dropIndex and listIndexes in JDBC (MySQL dialect)

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/v2/MySQLIntegrationSuite.scala

@@ -24,8 +24,6 @@ import org.scalatest.time.SpanSugar._
 
 import org.apache.spark.SparkConf
 import org.apache.spark.sql.AnalysisException
-import org.apache.spark.sql.catalyst.analysis.IndexAlreadyExistsException
-import org.apache.spark.sql.connector.catalog.{Catalogs, Identifier, TableCatalog}
 import org.apache.spark.sql.connector.catalog.index.SupportsIndex
 import org.apache.spark.sql.connector.expressions.{FieldReference, NamedReference}
 import org.apache.spark.sql.execution.datasources.v2.jdbc.JDBCTableCatalog
@@ -121,31 +119,22 @@ class MySQLIntegrationSuite extends DockerJDBCIntegrationSuite with V2JDBCTest {
     assert(t.schema === expectedSchema)
   }
 
-  override def testIndex(tbl: String): Unit = {
-    val loaded = Catalogs.load("mysql", conf)
-    val jdbcTable = loaded.asInstanceOf[TableCatalog]
-      .loadTable(Identifier.of(Array.empty[String], "new_table"))
-      .asInstanceOf[SupportsIndex]
-    assert(jdbcTable.indexExists("i1") == false)
-    assert(jdbcTable.indexExists("i2") == false)
+  override def supportsIndex: Boolean = true
 
+  override def testIndexProperties(jdbcTable: SupportsIndex): Unit = {
     val properties = new util.Properties();
     properties.put("KEY_BLOCK_SIZE", "10")
     properties.put("COMMENT", "'this is a comment'")
-    jdbcTable.createIndex("i1", "", Array(FieldReference("col1")),
+    // MySQL doesn't allow property set on individual column, so use empty Array for
+    // column properties
+    jdbcTable.createIndex("i1", "BTREE", Array(FieldReference("col1")),
       Array.empty[util.Map[NamedReference, util.Properties]], properties)
 
-    jdbcTable.createIndex("i2", "",
-      Array(FieldReference("col2"), FieldReference("col3"), FieldReference("col5")),
-      Array.empty[util.Map[NamedReference, util.Properties]], new util.Properties)
-
-    assert(jdbcTable.indexExists("i1") == true)
-    assert(jdbcTable.indexExists("i2") == true)
-
-    val m = intercept[IndexAlreadyExistsException] {
-      jdbcTable.createIndex("i1", "", Array(FieldReference("col1")),
-        Array.empty[util.Map[NamedReference, util.Properties]], properties)
-    }.getMessage
-    assert(m.contains("Failed to create index: i1 in new_table"))
+    var index = jdbcTable.listIndexes()
+    // The index property size is actually 1. Even though the index is created
+    // with properties "KEY_BLOCK_SIZE", "10" and "COMMENT", "'this is a comment'", when
+    // retrieving index using `SHOW INDEXES`, MySQL only returns `COMMENT`.
+    assert(index(0).properties.size == 1)
+    assert(index(0).properties.get("COMMENT").equals("this is a comment"))
   }
 }

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/v2/V2JDBCTest.scala

@@ -17,9 +17,15 @@
 
 package org.apache.spark.sql.jdbc.v2
 
+import java.util
+
 import org.apache.log4j.Level
 
 import org.apache.spark.sql.AnalysisException
+import org.apache.spark.sql.catalyst.analysis.{IndexAlreadyExistsException, NoSuchIndexException}
+import org.apache.spark.sql.connector.catalog.{Catalogs, Identifier, TableCatalog}
+import org.apache.spark.sql.connector.catalog.index.SupportsIndex
+import org.apache.spark.sql.connector.expressions.{FieldReference, NamedReference}
 import org.apache.spark.sql.jdbc.DockerIntegrationFunSuite
 import org.apache.spark.sql.test.SharedSparkSession
 import org.apache.spark.sql.types._
@@ -181,12 +187,93 @@ private[v2] trait V2JDBCTest extends SharedSparkSession with DockerIntegrationFu
     }
   }
 
-  def testIndex(tbl: String): Unit = {}
+  def supportsIndex: Boolean = false
+  def testIndexProperties(jdbcTable: SupportsIndex): Unit = {}
 
   test("SPARK-36913: Test INDEX") {
-    withTable(s"$catalogName.new_table") {
-      sql(s"CREATE TABLE $catalogName.new_table(col1 INT, col2 INT, col3 INT, col4 INT, col5 INT)")
-      testIndex(s"$catalogName.new_table")
+    if (supportsIndex) {
+      withTable(s"$catalogName.new_table") {
+        sql(s"CREATE TABLE $catalogName.new_table(col1 INT, col2 INT, col3 INT," +
+          s" col4 INT, col5 INT)")
+        val loaded = Catalogs.load(catalogName, conf)
+        val jdbcTable = loaded.asInstanceOf[TableCatalog]
+          .loadTable(Identifier.of(Array.empty[String], "new_table"))
+          .asInstanceOf[SupportsIndex]
+        assert(jdbcTable.indexExists("i1") == false)
+        assert(jdbcTable.indexExists("i2") == false)
+
+        val properties = new util.Properties();
+        val indexType = "DUMMY"
+        var m = intercept[UnsupportedOperationException] {
+          jdbcTable.createIndex("i1", indexType, Array(FieldReference("col1")),
+            Array.empty[util.Map[NamedReference, util.Properties]], properties)
+        }.getMessage
+        assert(m.contains(s"Index Type $indexType is not supported." +
+          s" The supported Index Types are: BTREE and HASH"))
+
+        jdbcTable.createIndex("i1", "BTREE", Array(FieldReference("col1")),
+          Array.empty[util.Map[NamedReference, util.Properties]], properties)
+
+        jdbcTable.createIndex("i2", "",
+          Array(FieldReference("col2"), FieldReference("col3"), FieldReference("col5")),
+          Array.empty[util.Map[NamedReference, util.Properties]], properties)
+
+        assert(jdbcTable.indexExists("i1") == true)
+        assert(jdbcTable.indexExists("i2") == true)
+
+        m = intercept[IndexAlreadyExistsException] {
+          jdbcTable.createIndex("i1", "", Array(FieldReference("col1")),
+            Array.empty[util.Map[NamedReference, util.Properties]], properties)
+        }.getMessage
+        assert(m.contains("Failed to create index: i1 in new_table"))
+
+        var index = jdbcTable.listIndexes()
+        assert(index.length == 2)
+
+        assert(index(0).indexName.equals("i1"))
+        assert(index(0).indexType.equals("BTREE"))
+        var cols = index(0).columns
+        assert(cols.length == 1)
+        assert(cols(0).describe().equals("col1"))
+        assert(index(0).properties.size == 0)
+
+        assert(index(1).indexName.equals("i2"))
+        assert(index(1).indexType.equals("BTREE"))
+        cols = index(1).columns
+        assert(cols.length == 3)
+        assert(cols(0).describe().equals("col2"))
+        assert(cols(1).describe().equals("col3"))
+        assert(cols(2).describe().equals("col5"))
+        assert(index(1).properties.size == 0)
+
+        jdbcTable.dropIndex("i1")
+        assert(jdbcTable.indexExists("i1") == false)
+        assert(jdbcTable.indexExists("i2") == true)
+
+        index = jdbcTable.listIndexes()
+        assert(index.length == 1)
+
+        assert(index(0).indexName.equals("i2"))
+        assert(index(0).indexType.equals("BTREE"))
+        cols = index(0).columns
+        assert(cols.length == 3)
+        assert(cols(0).describe().equals("col2"))
+        assert(cols(1).describe().equals("col3"))
+        assert(cols(2).describe().equals("col5"))
+
+        jdbcTable.dropIndex("i2")
+        assert(jdbcTable.indexExists("i1") == false)
+        assert(jdbcTable.indexExists("i2") == false)
+        index = jdbcTable.listIndexes()
+        assert(index.length == 0)
+
+        m = intercept[NoSuchIndexException] {
+          jdbcTable.dropIndex("i2")
+        }.getMessage
+        assert(m.contains("Failed to drop index: i2"))
+
+        testIndexProperties(jdbcTable)
+      }
     }
   }
 }

sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/index/SupportsIndex.java

@@ -42,7 +42,7 @@ public interface SupportsIndex extends Table {
    * @param columns the columns on which index to be created
    * @param columnsProperties the properties of the columns on which index to be created
    * @param properties the properties of the index to be created
-   * @throws IndexAlreadyExistsException If the index already exists (optional)
+   * @throws IndexAlreadyExistsException If the index already exists.
    */
   void createIndex(String indexName,
       String indexType,
@@ -55,10 +55,9 @@ void createIndex(String indexName,
    * Drops the index with the given name.
    *
    * @param indexName the name of the index to be dropped.
-   * @return true if the index is dropped
-   * @throws NoSuchIndexException If the index does not exist (optional)
+   * @throws NoSuchIndexException If the index does not exist.
    */
-  boolean dropIndex(String indexName) throws NoSuchIndexException;
+  void dropIndex(String indexName) throws NoSuchIndexException;
 
   /**
    * Checks whether an index exists in this table.

sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/index/TableIndex.java

@@ -53,27 +53,25 @@ public TableIndex(
   /**
    * @return the Index name.
    */
-  String indexName() { return indexName; }
+  public String indexName() { return indexName; }
 
   /**
    * @return the indexType of this Index.
    */
-  String indexType() { return indexType; }
+  public String indexType() { return indexType; }
 
   /**
    * @return the column(s) this Index is on. Could be multi columns (a multi-column index).
    */
-  NamedReference[] columns() { return columns; }
+  public NamedReference[] columns() { return columns; }
 
   /**
    * @return the map of column and column property map.
    */
-  Map<NamedReference, Properties> columnProperties() { return columnProperties; }
+  public Map<NamedReference, Properties> columnProperties() { return columnProperties; }
 
   /**
    * Returns the index properties.
    */
-  Properties properties() {
-    return properties;
-  }
+  public Properties properties() { return properties; }
 }

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/NoSuchItemException.scala

@@ -108,5 +108,5 @@ case class NoSuchPartitionsException(override val message: String)
 case class NoSuchTempFunctionException(func: String)
   extends AnalysisException(s"Temporary function '$func' not found")
 
-class NoSuchIndexException(indexName: String)
-  extends AnalysisException(s"Index '$indexName' not found")
+class NoSuchIndexException(message: String, cause: Option[Throwable] = None)
+  extends AnalysisException(message, cause = cause)

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JdbcUtils.scala

@@ -38,6 +38,7 @@ import org.apache.spark.sql.catalyst.parser.CatalystSqlParser
 import org.apache.spark.sql.catalyst.util.{CaseInsensitiveMap, DateTimeUtils, GenericArrayData}
 import org.apache.spark.sql.catalyst.util.DateTimeUtils.{instantToMicros, localDateToDays, toJavaDate, toJavaTimestamp}
 import org.apache.spark.sql.connector.catalog.TableChange
+import org.apache.spark.sql.connector.catalog.index.TableIndex
 import org.apache.spark.sql.connector.expressions.NamedReference
 import org.apache.spark.sql.errors.{QueryCompilationErrors, QueryExecutionErrors}
 import org.apache.spark.sql.execution.datasources.jdbc.connection.ConnectionProvider
@@ -1040,6 +1041,29 @@ object JdbcUtils extends Logging with SQLConfHelper {
     dialect.indexExists(conn, indexName, tableName, options)
   }
 
+  /**
+   * Drop an index.
+   */
+  def dropIndex(
+      conn: Connection,
+      indexName: String,
+      tableName: String,
+      options: JDBCOptions): Unit = {
+    val dialect = JdbcDialects.get(options.url)
+    executeStatement(conn, options, dialect.dropIndex(indexName, tableName))
+  }
+
+  /**
+   * List all the indexes in a table.
+   */
+  def listIndexes(
+      conn: Connection,
+      tableName: String,
+      options: JDBCOptions): Array[TableIndex] = {
+    val dialect = JdbcDialects.get(options.url)
+    dialect.listIndexes(conn, tableName, options)
+  }
+
   private def executeStatement(conn: Connection, options: JDBCOptions, sql: String): Unit = {
     val statement = conn.createStatement
     try {

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/jdbc/JDBCTable.scala

@@ -73,11 +73,18 @@ case class JDBCTable(ident: Identifier, schema: StructType, jdbcOptions: JDBCOpt
     }
   }
 
-  override def dropIndex(indexName: String): Boolean = {
-    throw new UnsupportedOperationException("dropIndex is not supported yet")
+  override def dropIndex(indexName: String): Unit = {
+    JdbcUtils.withConnection(jdbcOptions) { conn =>
+      JdbcUtils.classifyException(s"Failed to drop index: $indexName",
+        JdbcDialects.get(jdbcOptions.url)) {
+        JdbcUtils.dropIndex(conn, indexName, name, jdbcOptions)
+      }
+    }
   }
 
   override def listIndexes(): Array[TableIndex] = {
-    throw new UnsupportedOperationException("listIndexes is not supported yet")
+    JdbcUtils.withConnection(jdbcOptions) { conn =>
+      JdbcUtils.listIndexes(conn, name, jdbcOptions)
+    }
   }
 }

sql/core/src/main/scala/org/apache/spark/sql/jdbc/JdbcDialects.scala

@@ -31,6 +31,7 @@ import org.apache.spark.sql.AnalysisException
 import org.apache.spark.sql.catalyst.util.{DateFormatter, DateTimeUtils, TimestampFormatter}
 import org.apache.spark.sql.connector.catalog.TableChange
 import org.apache.spark.sql.connector.catalog.TableChange._
+import org.apache.spark.sql.connector.catalog.index.TableIndex
 import org.apache.spark.sql.connector.expressions.NamedReference
 import org.apache.spark.sql.errors.QueryCompilationErrors
 import org.apache.spark.sql.execution.datasources.jdbc.{JDBCOptions, JdbcUtils}
@@ -290,14 +291,15 @@ abstract class JdbcDialect extends Serializable with Logging{
   }
 
   /**
-   * Creates an index.
+   * Build a create index SQL statement.
    *
    * @param indexName         the name of the index to be created
    * @param indexType         the type of the index to be created
    * @param tableName         the table on which index to be created
    * @param columns           the columns on which index to be created
    * @param columnsProperties the properties of the columns on which index to be created
    * @param properties        the properties of the index to be created
+   * @return                  the SQL statement to use for creating the index.
    */
   def createIndex(
       indexName: String,
@@ -326,6 +328,27 @@ abstract class JdbcDialect extends Serializable with Logging{
     throw new UnsupportedOperationException("indexExists is not supported")
   }
 
+  /**
+   * Build a drop index SQL statement.
+   *
+   * @param indexName the name of the index to be dropped.
+   * @param tableName the table name on which index to be dropped.
+  * @return the SQL statement to use for dropping the index.
+   */
+  def dropIndex(indexName: String, tableName: String): String = {
+    throw new UnsupportedOperationException("dropIndex is not supported")
+  }
+
+  /**
+   * Lists all the indexes in this table.
+   */
+  def listIndexes(
+      conn: Connection,
+      tableName: String,
+      options: JDBCOptions): Array[TableIndex] = {
+    throw new UnsupportedOperationException("listIndexes is not supported")
+  }
+
   /**
    * Gets a dialect exception, classifies it and wraps it by `AnalysisException`.
    * @param message The error message to be placed to the returned exception.