Impala Overview#

What is Impala?#

Impala is a MPP (Massive Parallel Processing) SQL query engine for processing huge volumes of data that is stored in Hadoop cluster.

Impala	Relational databases
Impala uses an SQL like query language that is similar to HiveQL.	Relational databases use SQL language.
In Impala, you cannot update or delete individual records.	In relational databases, it is possible to update or delete individual records.
Impala does not support transactions.	Relational databases support transactions.
Impala does not support indexing.	Relational databases support indexing.
Impala stores and manages large amounts of data (petabytes).	Relational databases handle smaller amounts of data (terabytes) when compared to Impala.

HBase	Hive	Impala
HBase is wide-column store database based on Apache Hadoop. It uses the concepts of BigTable.	Hive is a data warehouse software. Using this, we can access and manage large distributed datasets, built on Hadoop.	Impala is a tool to manage, analyze data that is stored on Hadoop.
The data model of HBase is wide column store.	Hive follows Relational model.	Impala follows Relational model.
HBase is developed using Java language.	Hive is developed using Java language.	Impala is developed using C++.
The data model of HBase is schema-free.	The data model of Hive is Schema-based.	The data model of Impala is Schema-based.
HBase provides Java, RESTful and, Thrift API’s.	Hive provides JDBC, ODBC, Thrift API’s.	Impala provides JDBC and ODBC API’s.
Supports programming languages like C, C#, C++, Groovy, Java PHP, Python, and Scala.	Supports programming languages like C++, Java, PHP, and Python.	Impala supports all languages supporting JDBC/ODBC.
HBase provides support for triggers.	Hive does not provide any support for triggers.	Impala does not provide any support for triggers.