Update in Hive
Can I do row level updates in Hive? We are all aware of UPDATE not being a supported operation, based on past years of our experience of Hive. But guess what, it is no more a constraint, as UPDATE is available starting Hive 0.14 version. In this post we'll learn about the details of UPDATE in Hive(a long awaited operation for hadoop platform, as required by most of the Big data Engineers). We will learn about the following details: 1. The prerequisites for hive to perform update. 2. Syntax of update. 3. Hive configuration settings to do update. 4. A close look at what happens at Hadoop file system level when update operation is performed. 5. Limitations to UPDATE operation in Hive For a hive table to be updated(as of the date of publishing this article) : 1. It should be stored as ORC file format . 2. It should be bucketed . 3. It should support transactions(ACID semantics enabled) . Standard Syntax: UPDATE tablename SET column = value [, column = v...