Question-91: List the main component of HBase?

Answer: Zookeeper, Catalog Tables, Master, RegionServer, Region

Question-92: Please tell us Operational command in Hbase, we you have used?

Answer:  There are five main command in HBase.

1. Get
2. Put
3. Delete
4. Scan
5. Increment

Question-93: Write down the Java Code snippet to open a connection in HBase?

Answer: If you are going to open connection with the help of Java API. The following code provide the connection

Configuration myConf = HBaseConfiguration.create();

HTableInterface usersTable = new HTable(myConf, "users"); 

Question-94: What is ObjectInspector functionality?

Answer: Hive uses ObjectInspector to analyze the internal structure of the row object and also the structure of the individual columns. ObjectInspector provides a uniform way to access complex objects that can be stored in multiple formats in the memory, including:

• Instance of a Java class (Thrift or native Java)
• A standard Java object (we use java.util.List to represent Struct and Array, and use java.util.Map to represent Map)
• A lazily-initialized object (For example, a Struct of string fields stored in a single Java string object with starting offset for each field) A complex object can be represented by a pair of ObjectInspector and Java Object. The ObjectInspector not only tells us the structure of the Object, but also gives us ways to access the internal fields inside the Object.

Question-95: What is the functionality of Query Processor in Apache Hive?

Answer: This component implements the processing framework for converting SQL to a graph of map/reduce jobs and the execution time framework to run those jobs in the order of dependencies.