HBase Online Quiz


Following quiz provides Multiple Choice Questions (MCQs) related to HBase. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - The Value that is unique across all the rows in Hbase table is

A - Rownum

B - RowIndex

C - RowID

D - RowKey

Answer : D


Rowkey is the value which is the unique values across all the rows.

Q 2 - When a compaction operates over all HFiles in a column family in a given region, it is called

A - Major compaction

B - Family compaction

C - Final compaction

D - Full Compaction

Answer : A


IN a Major compaction all the HFIles of a column family for a given region are acted upon.

Q 3 - The data type of a rowkey is

A - String

B - Number

C - Data

D - Byte

Answer : D


The rowkey values are stored as a byte data.

Q 4 - The two tables which are used to find where regions of various tables are hosted are

A - Regiontab and Metatab

B - Regionbase and Metabase

C - –ROOT- and .META.

D - –ROOT- and .REGION.

Answer : C


The –ROOT_ and >META> table hold the data to find the location of regions.

Q 5 - When a map tasks in a mapreduce job reads from the Hbase table, it reads from

A - One row

B - One column family

C - One column

D - One region

Answer : D


Each map tasks reading a Hbase table reads from a region.

Q 6 - Which of the following is declared during the schema definition creation?

A - Column families

B - Column names

C - Both

D - None

Answer : A


The column families are declared upfront during the schema definition creation. But the column names can be declared anytime when the Table is up and running.

Answer : D


Hbase can store any data that can be converted to bytes.

Answer : D


The two classes provided by co-processors to extend it custom its functionalities are −


Q 9 - What is part of the directory name where Hbase data is stored?

A - Table name

B - Column qualifier

C - Column family

D - HFile

Answer : C


The column family is part of the directory name where the Hbase data is stored. It must be made up of printable characters.

Q 10 - In Hbase there are two situations when the WAL logfiles needs to be replayed. One is when the server fails. The other is when

A - The logs are full

B - Rows are deleted.

C - The cluster fails

D - Rows are updated

Answer : C


The only two instances when the logs are replayed is when cluster starts or the server fails.