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

Question :

You want to do mostly full table scans on your data. In order to improve performance you increase your block
size. Why does this improve your scan performance?


1. It does not. Increasing block size does not improve scan performance.
2. It does not. Increasing block size means that fewer blocks fit into your block cache. This requires HBase to
read each block from disk rather than cache for each scan, thereby decreasing scan performance.
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4. Increasing block size means fewer block indexes that need to be read from disk, thereby increasing scan performance.




Correct Answer : Get Lastest Questions and Answer :

Change HFile block size to something bigger to improve scan (at cost of random read).




Question :

Your client application connects to HBase for the first time and queries the .META. table. What information
does the .META. table provide to your client application?


1. The location of a Region
2. The location of an MMaster
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4. The location of a ROOT table




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The .META. table keeps a list of all regions in the system. The .META. table structure is as follows:
Key:
Region key of the format ([table],[region start key],[region id]) Values:

info:regioninfo (serialized HRegionInfo instance for this region) info:server (server:port of the RegionServer
containing this region) info:serverstartcode (start-time of the RegionServer process containing this region)





Question :

You have a table where keys range from "A" to "Z", and you want to scan from "D" to "H." Which of the
following is true?


1. A MultiGet must be issued for rows D, E, F, G, H.
2. The scan class supports ranges via the stop and start rows.
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4. In order to range scan, raw scan mode must be enabled.

Correct Answer : Get Lastest Questions and Answer :

Rather than specifying a single row, an optional startRow and stopRow may be defined. If rows are not
specified, the Scanner will iterate over all rows.

Related Questions

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Question : You have created an HBase application called Acmeshell and from within Acmeshell, you want to create a new table named AcmeLogs.
In this AcmeLogs table you will be storing 2 Billion Mobile advertisement and its clickstream information. You start with the following Java code:
You have already created HBaseAdmin object ( name of object acmeAdmin)using the configuration as well as HTableDescriptor with
table name "AcmeLogs". Now you want to finally create the table using HTableDescriptor, select the correct command.

1. HTable.createTable(acmeTable);
2. HBaseAdmin.createTable(acmeTable);
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4. acmeAdmin.createTable(acmeTable);




Question : You have created an advertising application based on HBase called Acmeshell
in Acmeshell you wish to insert text using the add method, with the add text you also want to store the time when the click happened
on the advertisement, in HBase select the correct syntax so that you can also store click timestamp using the Put class?

1. put.add(column_family, column_qualifier, data, click_timestamp)

2. put.add(column_family, column_qualifier, click_timestamp, data)

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4. put.insert(click_timestamp, column_family, column_qualifier, data)





Question :

Select the correct statement for deciding number of column families..

1. Recommend no more than three Column Families
2. Column Families are defined by access scope
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4. All 1,2 and 3 are correct
5. only 1 and 3 are correct




Question :

Select the wrong point about the In Memory ColumnFamilies


1. ColumnFamilies can be defined as in-memory
2. Data is still persisted to disk
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4. Not guaranteed that the entire table will be in memory
5. None of the above




Question :

Select the correct statement for the Time to Live (TTL) for column family



1. ColumnFamilies can set a TTL length in seconds
2. Rows will automatically delete when expiration time is reached
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4. Used in conjunction with minimum versions setting
5. All of the above





Question :

While designoing the row key which of the following is correctly applies..


1. Rowkeys cannot be changed
2. Rows are sorted on insert not on scan
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4. All 1,2 and 3 are applies
5. Only 1 and 2 applies