HBase Online Quiz


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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

Answer : C

Explanation

Hbase is a schema less database as it stores data in column families which does not have a fixed or rigid structure to follow.

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

Explanation

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

Q 3 - Filters in Hbase can be applied to

A - Rowkeys

B - Column qualifiers

C - Data values

D - All of the above

Answer : D

Explanation

Filetrs can be applied to rowkeys,column qualifiers and data values.

Q 4 - When a client application wants to access a row in a Hbase table it first queries the table

A - –ROOT-

B - .META.

C - .REGIONS.

D - .ALLREGIONS.

Answer : A

Explanation

The client first goes to the –ROOT- table which gives further information on which .META. table to refer.

Q 5 - In a Map-Side join, we take rows from one table and map it with rows from the other table. The size of one of the table should be

A - Enough to fit into memory

B - Half the size of the other table

C - Double the size of the other table

D - Small enough to be located in one physical machine

Answer : A

Explanation

If you join two datasets where at least one of them can fit in memory of the map task,then load the smaller dataset into a hash-table so the map tasks can access it while iterating over the other dataset. In these cases, you can skip the Shuffle and Reduce Steps entirely and emit your final

output from the Map Step.

Answer : D

Explanation

By default HBase runs in standalone mode. For a fully distributed configuration set the hbase-cluster.distributed property to true.

Q 7 - The schema level changes to table or column families(like region size, block size etc) are reflected

A - Immediately after the changes

B - Only after a major compaction

C - Only after a minor compaction

D - Restarting the Regionserver.

Answer : B

Explanation

Only after a major compaction and the StoreFiles get re-written the schema level changes are available.

Q 8 - Which filer accepts the pagesize as a parameter?

A - Columnfilter

B - Valuefilter

C - Pagefilter

D - Keyfilter

Answer : C

Explanation

This filter gives the query result in different pages using Pagesize parameter.

Q 9 - The metadata of region is accessed using the file named

A - .metainfo

B - .metaregion

C - .regioninfo

D - .regionmetainfo

Answer : C

Explanation

The file .regioninfo stores the metadata information.

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

Explanation

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


hbase_questions_answers.htm

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