Chapter 7. Using Spark SQL

Spark SQL can read data directly from the filesystem, when SQLContext is used. This is useful when the data you are trying to analyze does not reside in Hive (for example, JSON files stored in HDFS).

Spark SQL can also read data by interacting with the Hive MetaStore, when HiveContext is used. If you already use Hive, you should use HiveContext; it supports all Hive data formats and user-defined functions (UDFs), and allows full access to the HiveQL parser. HiveContext extends SQLContext, so HiveContext supports all SQLContext functionality.

There are two ways to interact with Spark SQL:

The following diagram outlines the access process, depending on type of interaction:

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