CCD-410 Real Exam Prep DEMO

Question 4: Table metadata in Hive is:
A. Stored as metadata on the NameNode.
B. Stored along with the data in HDFS.
C. Stored in the Metastore.
D. Stored in ZooKeeper.
Correct Answer: C
Explanation:
By default, hive use an embedded Derby database to store metadata information.
The metastore is the "glue" between Hive and HDFS. It tells Hive where your data files live in
HDFS, what type of data they contain, what tables they belong to, etc.
The Metastore is an application that runs on an RDBMS and uses an open source ORM layer
called DataNucleus, to convert object representations into a relational schema and vice versa.
They chose this approach as opposed to storing this information in hdfs as they need the
Metastore to be very low latency. The DataNucleus layer allows them to plugin many different
RDBMS technologies.
Note:
*By default, Hive stores metadata in an embedded Apache Derby database, and other
client/server databases like MySQL can optionally be used.
*features of Hive include:
Metadata storage in an RDBMS, significantly reducing the time to perform semantic checks during
query execution.
Reference: Store Hive Metadata into RDBMS