HADOOP-PR000007 試験問題を無料オンラインアクセス

Which one of the following statements is false about HCatalog?

• A.Provides a shared schema mechanism
• B.Designed to be used by other programs such as Pig, Hive and MapReduce
• C.Stores HDFS data in a database for performing SQL-like ad-hoc queries
• D.Exists as a subproject of Hive

What does Pig provide to the overall Hadoop solution?

• A.Legacy language Integration with MapReduce framework
• B.C++ interface to MapReduce and data warehouse infrastructure
• C.Database table and storage management services
• D.Simple scripting language for writing MapReduce programs

Consider the following two relations, A and B.

What is the output of the following Pig commands?
X = GROUP A BY S1; DUMP X;

• A.Option B
• B.Option D
• C.Option A
• D.Option C

When can a reduce class also serve as a combiner without affecting the output of a MapReduce program?

• A.When the types of the reduce operation's input key and input value match the types of the reducer's output key and output value and when the reduce operation is both communicative and associative.
• B.Never. Combiners and reducers must be implemented separately because they serve different purposes.
• C.Always. Code can be reused in Java since it is a polymorphic object-oriented programming language.
• D.When the signature of the reduce method matches the signature of the combine method.
• E.Always. The point of a combiner is to serve as a mini-reducer directly after the map phase to increase performance.

Which one of the following statements is FALSE regarding the communication between DataNodes and a
federation of NameNodes in Hadoop 2.0?

• A.Each DataNode receives commands from one designated master NameNode.
• B.Each DataNode registers with all the NameNodes.
• C.DataNodes send periodic heartbeats to all the NameNodes.
• D.DataNodes send periodic block reports to all the NameNodes.