Github user jackylk commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/1878#discussion_r164654501
--- Diff:
integration/spark2/src/main/scala/org/apache/spark/sql/execution/command/table/ShowTablesCommand.scala
---
@@ -0,0 +1,72 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command.table
+
+import scala.collection.JavaConverters._
+
+import org.apache.spark.sql.{CarbonEnv, Row, SparkSession}
+import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.expressions.{Attribute,
AttributeReference}
+import org.apache.spark.sql.execution.command.MetadataCommand
+import org.apache.spark.sql.types.{BooleanType, StringType}
+
+
+private[sql] case class ShowTablesCommand ( databaseName: Option[String],
+ tableIdentifierPattern: Option[String]) extends MetadataCommand{
+
+ // The result of SHOW TABLES has three columns: database, tableName and
isTemporary.
+ override val output: Seq[Attribute] = {
+ AttributeReference("database", StringType, nullable = false)() ::
+ AttributeReference("tableName", StringType, nullable = false)() ::
+ AttributeReference("isTemporary", BooleanType, nullable = false)() ::
Nil
+ }
+
+ override def processMetadata(sparkSession: SparkSession): Seq[Row] = {
+ // Since we need to return a Seq of rows, we will call getTables
directly
+ // instead of calling tables in sparkSession.
+ // filterDataMaps Method is to Filter the Table.
+ val catalog = sparkSession.sessionState.catalog
+ val db = databaseName.getOrElse(catalog.getCurrentDatabase)
+ var tables =
+ tableIdentifierPattern.map(catalog.listTables(db,
_)).getOrElse(catalog.listTables(db))
+ tables = filterDataMaps(tables, sparkSession)
+ tables.map { tableIdent =>
+ val isTemp = catalog.isTemporaryTable(tableIdent)
+ Row(tableIdent.database.getOrElse(""), tableIdent.table, isTemp)
+ }
+ }
+
+ private def filterDataMaps(tables: Seq[TableIdentifier],
+ sparkSession: SparkSession): Seq[TableIdentifier] = {
+ // Filter carbon Tables then get CarbonTable and getDataMap List and
filter the same
+ // as of now 2 times lookup is happening(filter carbon table
,getDataMapList)
+ // <todo> add another PR to improve with 1 lookup
+ val allDatamapTable = tables.filter(tbs => {
--- End diff --
`tables.filter(tbs => {` change to
`tables.filter { table =>`
---
