shark.util.QueryRewriteUtils.scala Maven / Gradle / Ivy

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/*
 * Copyright (C) 2012 The Regents of The University California.
 * All rights reserved.
 *
 * Licensed 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 shark.util

import org.apache.hadoop.hive.ql.parse.SemanticException

object QueryRewriteUtils {

  def cacheToAlterTable(cmd: String): String = {
    val CACHE_TABLE_DEFAULT = "(?i)CACHE ([^ ]+)".r
    val CACHE_TABLE_IN = "(?i)CACHE ([^ ]+) IN ([^ ]+)".r

    cmd match {
      case CACHE_TABLE_DEFAULT(tableName) =>
        s"ALTER TABLE $tableName SET TBLPROPERTIES ('shark.cache' = 'memory')"
      case CACHE_TABLE_IN(tableName, cacheType) =>
        s"ALTER TABLE $tableName SET TBLPROPERTIES ('shark.cache' = '$cacheType')"
      case _ =>
        throw new SemanticException(
          s"CACHE accepts a single table name: 'CACHE  [IN ]'" +
            s" (received command: '$cmd')")
    }
  }

  def uncacheToAlterTable(cmd: String): String = {
    val cmdSplit = cmd.split(' ')
    if (cmdSplit.size == 2) {
      val tableName = cmdSplit(1)
      "ALTER TABLE %s SET TBLPROPERTIES ('shark.cache' = 'false')".format(tableName)
    } else {
      throw new SemanticException(
        s"UNCACHE accepts a single table name: 'UNCACHE ' (received command: '$cmd')")
    }  
  }
}




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