| |
| //// |
| 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 |
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| http://www.apache.org/licenses/LICENSE-2.0 |
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| 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. |
| //// |
| |
| The merge tool allows you to combine two datasets where entries in one |
| dataset should overwrite entries of an older dataset. For example, an |
| incremental import run in last-modified mode will generate multiple datasets |
| in HDFS where successively newer data appears in each dataset. The +merge+ |
| tool will "flatten" two datasets into one, taking the newest available |
| records for each primary key. |
| |
| |
