In the following post, we will cover Hive Introduction and key principles of Hive. Hive Introduction – Benefits and Limitations Hive is a data warehouse tool developed on top of Hadoop to process structured data. This is basically a wrapper written …
The below diagram represents Hadoop Hive Architecture and typical query that flows through the HIVE system. The UI calls the execute query interface to the driver. The driver creates a session handle for the query and sends the query to …
In this post, we will discuss Hive data types and file formats. Hive Data Types Hive supports most of the primitive data types that we find in relational databases. It also supports three collection data types that are rarely supported …
Some of the key Hive components that we are going to learn in this post are UI, Driver, Compiler, Metastore, and Execution engine. Let us understand these Hive components one by one in detail below. Apache Hive components Hive User …
In this section, we will discuss data definition language parts of HIVE Query Language(HQL), which are used for creating, altering and dropping databases, tables, views, functions, and indexes. We will also look into SHOW and DESCRIBE commands for listing and …
In the below post we are going to understand about HIVE Partition and Concepts of HIVE partitioning in detail. Partitions are essentially horizontal slices of data that divides the larger set of data into small manageable chunks. In HIVE, partitioning …
HIVE UDF (User Defined Functions) allow the user to extend HIVE Query Language. Once the UDF is added in the HIVE script, it works like a normal built-in function. To check which all UDFs are loaded in current hive session, …
Unlike partitioning, HIVE bucketing is another way to decompose data into more manageable sets. Consider our requirement is to create the partition based on date and then on user ID’s. In this case, there will be more numbers of small …
It is important to note that HiveQL data manipulation doesn’t offer any row-level insert, update or delete operation. Therefore, data can be inserted into hive tables using either “bulk” load operations or writing the files into correct directories by other …
Hive Query is similar to SQL. Hive queries are written in HiveQL and can be used to query the data without knowledge of Java or MapReduce. Hive Query – HiveQL SELECT … FROM Clause SELECT … FROM clause is almost same as SQL. …
We can extend and have custom Hive using the User Defined Functions (UDFs). To demonstrate the process let us look at the below example. Prerequisites for Custom Hive We have to extend “our class” to the UDF abstract class. “Our …