You can use the Apache Hive set operators to combine similar data sets from two or more SELECT statements into a single result set . Here the similar data set literally mean, the data type of the result set should also match. Otherwise, you have to explicitly convert type using type conversion functions. Hive Set Operators Hadoop Hive supports following set operators. UNION [DISTINCT] UNION ALL Hive versions prior to 1.2.0 only support UNION ALL (bag union), in which duplicate rows are not eliminated. Starting version 1.2.0, Hive includes optional ALL keywords.…

The join in Hive is used to combine the records from multiple tables based on the joining condition. The joining condition can be on the common columns between participating tables. Hadoop Hive supports various join types. You may get the requirement to choose the joining values based on certain conditions. For example, you can have OR condition in the joining condition. In this article, we will check how to write Conditional Join in Hive with some examples. Hive Conditional Join You never know what type of requirement that you are…

The Relational databases like SQL server supports writing queries on a relatively small number of rows from the very large table. In this article, we will check Hive table sampling concept, methods and some examples. Hive Table Sampling Concept The Hive TABLESAMPLE clause allows the users to write queries for samples of the data instead of the whole table. The sampling comes handy when you are working on the large tables and it takes time to return results. The TABLESAMPLE clause can be added to any table in the FROM…

In a data warehouse environment, there are many options that you can check for an integer value. Using this process, you can usually remove the unwanted records and save some I/O. For example, filter out non-numeric values when comparing it with integer types. In this article, we see different methods to check integer value in Hive. Apache Hive Integer Value Check Many relational databases provide an extended SQL function to help the data warehouse developers. The built-in functions such isnumeric is used to check given string value is a number…

In a data warehouse environment, you will be working with heterogeneous data set. You may have to filter out unwanted data before loading it to the actual data into Hive table. For example, you many have a field1 of type string contains alphanumeric values. In many scenarios, you may get requirement to filter out non-numeric values. In this article, we will check Hadoop Hive isnumeric Alternative with some examples. Hadoop Hive isnumeric Function Many relational databases provide an extended SQL functions to help the data warehouse developers. Databases such as…