//// 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. //// Importing Data Into Hive ^^^^^^^^^^^^^^^^^^^^^^^^ Sqoop's import tool's main function is to upload your data into files in HDFS. If you have a Hive metastore associated with your HDFS cluster, Sqoop can also import the data into Hive by generating and executing a +CREATE TABLE+ statement to define the data's layout in Hive. Importing data into Hive is as simple as adding the *+\--hive-import+* option to your Sqoop command line. If the Hive table already exists, you can specify the *+\--hive-overwrite+* option to indicate that existing table in hive must be replaced. After your data is imported into HDFS or this step is omitted, Sqoop will generate a Hive script containing a +CREATE TABLE+ operation defining your columns using Hive's types, and a +LOAD DATA INPATH+ statement to move the data files into Hive's warehouse directory. The script will be executed by calling the installed copy of hive on the machine where Sqoop is run. If you have multiple Hive installations, or +hive+ is not in your +$PATH+, use the *+\--hive-home+* option to identify the Hive installation directory. Sqoop will use +$HIVE_HOME/bin/hive+ from here. NOTE: This function is incompatible with +\--as-avrodatafile+ and +\--as-sequencefile+. Even though Hive supports escaping characters, it does not handle escaping of new-line character. Also, it does not support the notion of enclosing characters that may include field delimiters in the enclosed string. It is therefore recommended that you choose unambiguous field and record-terminating delimiters without the help of escaping and enclosing characters when working with Hive; this is due to limitations of Hive's input parsing abilities. If you do use +\--escaped-by+, +\--enclosed-by+, or +\--optionally-enclosed-by+ when importing data into Hive, Sqoop will print a warning message. Hive will have problems using Sqoop-imported data if your database's rows contain string fields that have Hive's default row delimiters (+\n+ and +\r+ characters) or column delimiters (+\01+ characters) present in them. You can use the +\--hive-drop-import-delims+ option to drop those characters on import to give Hive-compatible text data. Alternatively, you can use the +\--hive-delims-replacement+ option to replace those characters with a user-defined string on import to give Hive-compatible text data. These options should only be used if you use Hive's default delimiters and should not be used if different delimiters are specified. Sqoop will pass the field and record delimiters through to Hive. If you do not set any delimiters and do use +\--hive-import+, the field delimiter will be set to +^A+ and the record delimiter will be set to +\n+ to be consistent with Hive's defaults. The table name used in Hive is, by default, the same as that of the source table. You can control the output table name with the +\--hive-table+ option. Hive can put data into partitions for more efficient query performance. You can tell a Sqoop job to import data for Hive into a particular partition by specifying the +\--hive-partition-key+ and +\--hive-partition-value+ arguments. The partition value must be a string. Please see the Hive documentation for more details on partitioning. You can import compressed tables into Hive using the +\--compress+ and +\--compression-codec+ options. One downside to compressing tables imported into Hive is that many codecs cannot be split for processing by parallel map tasks. The lzop codec, however, does support splitting. When importing tables with this codec, Sqoop will automatically index the files for splitting and configuring a new Hive table with the correct InputFormat. This feature currently requires that all partitions of a table be compressed with the lzop codec.