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

Question :

Select the correct statement for the Put operation

1. It is used to add a row to a table
2. It Takes the row key as a byte array
3. Access Mostly Uused Products by 50000+ Subscribers
4. Only 3 correct
5. All 1,2 and 3 are correct



Correct Answer : Get Lastest Questions and Answer :

Put operation Used to add a row to a table
- Takes the row key as a byte array
- Use Bytes.toBytes(String) to convert a string to byte array

Add method takes various forms:
- add(byte[] colfam, byte[] columns, byte[] value)
- add(byte[] colfam, byte[] column, long ts, byte[] value)
- add(byte[] colfam_and_column, byte[] value)

Put p = new Put(Bytes.toBytes("rowkey"));
p.add(Bytes.toBytes("colfam"),Bytes.toBytes("column"),Bytes.toBytes("value"));
table.put(p);





Question :

While adding multiple data using Batch data into a single put, which of the following staement is wrong


1. Concurrent readers will not see partially written rows
2. Concurrent writers will not update the same row
3. Access Mostly Uused Products by 50000+ Subscribers
4. 1 and 2 are wrong
5. None of 1,2 and 3 is wrong





Correct Answer : Get Lastest Questions and Answer :

Explanation:
Use constants for column family and column name
- Avoids calling Bytes.toBytes more times than necessary
Batch data into a single put
- Concurrent readers will not see partially written rows
- Concurrent writers will not update the same row
- Records with same rowkey/column will have different timestamp
Put method can also take a List of Put
Put p = new Put(Bytes.toBytes("rowkey"));
p.add(META, FNAME, Bytes.toBytes("John"));
p.add(META, LNAME, Bytes.toBytes("Peter"));
p.add(..);
table.put(p);






Question : Select the correct mapping

A setAutoFlush(boolean)
B flushCommits()

X. Buffers the put operations
Y. Executes all buffered operations
Z. Buffer is automatically flushed when it becomes full


1. X and Y applies to A
2. Y and Z applies to B
3. Access Mostly Uused Products by 50000+ Subscribers
4. X,Y and Z all applies to A
5. X,Y and Z all applies to B




Correct Answer : Get Lastest Questions and Answer :


Explanation:
setAutoFlush(boolean);
- Buffers the put operations
- Buffer is automatically flushed when it becomes full
flushCommits()
- Executes all buffered operations

Related Questions

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Question : Which is correct for the Data Storage concept in Hbase


1. Data is written to the Regions MemStore
2. When the MemStore gets to a certain size, it will flush to an immutable file (Store file)
3. Access Mostly Uused Products by 50000+ Subscribers
4. All of the above



Question : In the minor compactation...


1. Combines some store files in a Single file
2. Runs after three store files have accumulated
3. Access Mostly Uused Products by 50000+ Subscribers
4. All 1,2 and 3 are correct
5. Only 1 and 2 are correct




Question : Major compaction ......


1. Reads all the Store files and writes to a single Store
2. Deleted rows and expired versions are removed
3. Access Mostly Uused Products by 50000+ Subscribers
4. None of the 1,2 and 3 are correct
5. All 1,2 and 3 are correct


Question : Which is or are true for Major Compaction
1. Can be configured with hbase.hregion.majorcompaction
2. Heavyweight operation - run when load is low
3. Access Mostly Uused Products by 50000+ Subscribers
4. MemStore can flush to disk during compaction



1. 1,2 and 3
2. 1 and 2
3. Access Mostly Uused Products by 50000+ Subscribers
4. 1 and 3
5. 1 and 4



Question : Minor Compaction ....

1. Can be configured with hbase.hstore.compactionThreshold
2. Larger number of compactions will take longer but will be fewer
3. Access Mostly Uused Products by 50000+ Subscribers
4. All 1,2 and 3 are correct




Question : HLog is an WAL (Write Ahead Log ) implementation

1. True
2. False