HBase Mock Test


This section presents you various set of Mock Tests related to HBase. You can download these sample mock tests at your local machine and solve offline at your convenience. Every mock test is supplied with a mock test key to let you verify the final score and grade yourself.

Questions and Answers

HBase Mock Test I

Answer : D

Explanation

Hbase is a versatile data base which can handle both unstructured and structured data.

Q 2 - Columns in Hbase are organized to

A - Column Group

B - Column families

C - Column list

D - Column base

Answer : B

Explanation

In Hbase columns are organized to column families.

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

A - Rownum

B - RowIndex

C - RowID

D - RowKey

Answer : D

Explanation

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

Answer : C

Explanation

Rowkey ,table name and column name create a unique combination which can identify a piece of data in Hbase.

Q 6 - Which of the following is not one of the primitive commands to interact with Hbase

A - Drop

B - Get

C - Put

D - Scan

Answer : A

Explanation

The five primitive commands for interacting with Hbase are Get, put, Delete, Scan and Increment.

Q 7 - There are 2 programs which confirm a write into Hbase. One is write-ahead log(WAL) and the other one is

A - Mem confirm log

B - Write complete log

C - log store

D - Memstore

Answer : D

Explanation

The write access log and Memstore confirm the writing of a Hbase value.

Answer : A

Explanation

There is only one Memstore per column family

Q 9 - The number of HF files, one column family in Habse can have is

A - Equal to number of columns in the column family

B - More than one

C - Only one

D - Only tow

Answer : B

Explanation

Onr column family can have multiple HF files associated with it.

Answer : B

Explanation

A single HF file can be associated with only one column family.

Q 11 - While reading data from Hbase the command used to get only a specific column instead of all the columns in a column family is

A - Onecolumn

B - Addcolumn

C - FilterCOlumn

D - Dropcolumns

Answer : A

Explanation

The addcolumn() command displays result for specific column given as a input to this command rather than all the columns in a table, which is the default behavior.

Answer : A

Explanation

The addFamily() command displays all the columns of a specific column family.

Q 13 - While reading from Hbase the sequence in which the read happens is

A - MemCache,Blockcache,HFile

B - Blockcache,HFile,Memcache

C - MemCache,HFile,Blockcache

D - HFile,Memcache,Blockcache

Answer : A

Explanation

The order is first read the Memcache, then the Blockcache and finally the HFile.

Q 14 - A record deleted in Hbase is not removed from Hbase immediately. Instead it is written to another file and marked as Delete. Such a file is Known as

A - DFile

B - Tombfile

C - Tombstone

D - Earmark

Answer : C

Explanation

The deleted records are stored in file is known as Tombstone.

Q 15 - The deleted records in Hbase are stored in the file known as Tombstone. Then the space in freed only by truly removing these records from Hbase. This process is known as

A - Compaction

B - Retraction

C - Consolidation

D - Separation

Answer : A

Explanation

The process of merging tombstone files and creating a new HFile only containing the records not marked for delete is known as compaction.

Q 16 - 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.

Answer : A

Explanation

At the end of major compaction one column family gets one HFile.

Answer : D

Explanation

All the three events of creating,modifying and Deleting a record create a new version of the record inHbase.

Q 19 - Each version of data within a cell adds a versioning information through a

A - VersionNo

B - KeyValue

C - KeyNo

D - VersionValue

Answer : B

Explanation

Each version of data within a cell contributes one KeyValue instance to the Result.

Q 20 - The verison information of a record in a KeyValue instance is inspected using the method

A - getVersion()

B - getTimestamp()

C - getTime()

D - getVersioninfo()

Answer : B

Explanation

The getTimestamp() method is used to inspect the specific verison associated with a KeyValue Instance.

Q 21 - The method which deletes a specific version within a cell is

A - Deletecolumns()

B - Deletecolumn()

C - Deleteversionno()

D - Deletespecific()

Answer : B

Explanation

The deletecolumn() deletes a specific version but deletecolumns() deletes all the versions in a cell prior to the specified version.

Q 22 - The data type of a rowkey is

A - String

B - Number

C - Data

D - Byte

Answer : D

Explanation

The rowkey values are stored as a byte data.

Answer : D

Explanation

Every row in a table has the same column families, although a row need not store data in all its families.

Q 24 - The values stored inside a cell which is identified using a rowkey, column family and column qualifier is stored as

A - Byte

B - Number

C - Varchar

D - Nchar

Answer : A

Explanation

The data stored inside a cell is always in Byte format.

Q 25 - The default number of versions of a cell value which Hbase can store is

A - 2

B - 3

C - 8

D - Unlimited

Answer : B

Explanation

Hbase stores 3 version of a value in a cell. But this can be configured to a higher value.

Answer Sheet

Question Number Answer Key
1 D
2 B
3 C
4 D
5 C
6 A
7 D
8 A
9 B
10 B
11 A
12 A
13 A
14 C
15 A
16 A
17 A
18 D
19 B
20 B
21 B
22 D
23 D
24 A
25 B
hbase_questions_answers.htm
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