Cloudera HBase Certification Questions and Answers (Dumps and Practice Questions)

Question : Which statement is correct regarding the Put operation for inserting the data

1. It doen not replace existing Cell
2. Always creates a new versions of the Cell
3. Default version is the Server's currentTimeMillis
4. Versions can be specified on a per-column basis
5. All of the above



Correct Answer : 5

Put inserts data
Does not "replace" an existing cell
Always creates a new version of the cell
Default version is the servers currentTimeMillis
Versions can be specified on a per-column basis








Question : Which of the code segment can be used to explicitely set the version time as


1. put.add(Bytes.toBytes("cf"), Bytes.toBytes("attr1"), 777, Bytes.toBytes(data));
2. put.add(Bytes.toBytes("cf"), Bytes.toBytes("attr1"), "777", Bytes.toBytes(data));
3. put.add(Bytes.toBytes("cf"), Bytes.toBytes("attr1"), Bytes.toBytes(data), "777");
4. None of the above is correct

Correct Answer : 1

Version timestamp explicitly set to "777"
Put put = new Put( Bytes.toBytes(row ));
long explicitTimeInMs = 777;
put.add(Bytes.toBytes("cf"), Bytes.toBytes("attr1"), explicitTimeInMs, Bytes.toBytes(data));
htable.put(put);







Question : Which statement is true regarding the data delete in HBase
table


1. Deleted data is not immediately removed
2. Delete creates a tombstone marker
3. Tombstones masks the deleted values
4. Data is removed at major compaction
5. All of the above


Correct Answer : 5

Delete marks data has having been deleted
Data is never modified in place
Deleted data isnt immediately removed
Delete creates a "tombstone marker"
Tombstone masks the deleted values
Data is removed at major compaction

Related Questions

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Question : To avoid the loss of older articles version you enabled the temporality in HBase database, so all the version of article can be saved. Now the column
in a table called ARTICLES, user_article_title has a version from 1 to 444 available for a article created by user JOHN with title "HBase Tutorial".
Now to bring the table in stable state you execute a delete statement for deleting version 445. Select the correct statement...


1. The entire row of conatining article will be deleted

2. Only cells with specified version 445 are deleted
3. As version 445 does not exist hence nothing in the row will be deleted

4. The delete fails with an error





Question : Given the following HBase table schema:( for user articles from QuickTechie.com website.)
Row Key, ArticleContent:userProfileName, ArticleContent_A:address, UserVersion:3, UserVersion:10
A table scan will return the column data in which sorted order?

1. Row Key, ArticleContent_Altered:address, ArticleContent:userProfileName, UserVersion:3, UserVersion:10
2. Row Key, ArticleContent_Altered:address,ArticleContent:userProfileName, UserVersion:10, UserVersion:3
3. Row Key, ArticleContent:userProfileName, ArticleContent_Altered:address, UserVersion:3, UserVersion:10
4. Row Key, ArticleContent:userProfileName, ArticleContent_Altered:address, UserVersion:10, UserVersion:3


Question : You are going to store this data in HBase file, select the order in which they will be stored.

Row # ROW KEY COLUMNFamilty:ColumnQualifier:timestamp Column Value
A 01012015002 Article:Metadata,timestamp=201, value=Ankit
B 01012015002 Article:User,timestamp=201, value=Baba
C 01012015001 BLOG:Title,timestamp=501, value=Chitrank
D 01012015001 BLOG:Author,timestamp=501, value=David
E 01012015002 Article:Number,timestamp=201, value=Eigen
F 01012015001 BLOG:Text,timestamp=501, value=Farukh


1. D, F, C, A, E, B
2. C, D, F, A, B, E
3. A, E, B, D, C, F

4. D, S, B, F, C, E


Question : To analysing the entire QuickTechie.com articles backup table stored in HBase, you found that it is not perfoming well and showing slowness.
You considered the block caching option, select the correct statement regarding the block caching enabling and disabling. Assume entire table size is 1TB and
available RAM is 128GB



1. Disabling block caching does not improve scan performance on the ARTICLE table.

2. When you disable block caching, you free up memory for MemStore which improves scan performance for ARTICLE table.
3. By disabling the block caching, it free up that memory for other operations. However, block caching would not help whether you diable or enable for scan operation. Because the entire table is 1TB and max available memory is 128GB, hence full table will not fit in 128GB
4. None of the above.


Question :

To drop a table it must be first disable ?

1. True
2. False




Question :

To change the column families it is not necessary to disable
the table

1. True
2. False