Hive Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to Hive. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Q 1 - The query "SHOW DATABASE LIKE 'h.*' ; gives the output with database name
Answer : B
Explanation
Hive support regular expressions which are derived from regex capabilities of Java language.
Q 2 - On dropping an external table
A - The schema gets dropped without dropping the data
Answer : A
Explanation
As the data is stored externally Hive only drops the schema.
Q 3 - If the directory for a partition does not exist, and a query is executed for this partition then
B - mapreduce job is not triggered
Answer : D
Explanation
The map reduce job is triggered but no result will be returned.
Q 4 - The position of a specific column in a Hive table
A - can be anywhere in the table creation clause
B - must match the position of the corresponding data in the data file
C - Must match the position only for date time data type in the data file
Answer : B
Explanation
It is up to the user to ensure the synchronization between schema and data
Q 5 - To select all columns starting with the word 'Sell' form the table GROSS_SELL the query is
A - select '$Sell*' from GROSS_SELL
B - select 'Sell*' from GROSS_SELL
Answer : C
Explanation
Hive supports java based regular expression for querying its metadata.
Q 6 - In case of one large table and 2 small tables, for an optimized query performance
A - The largest one should be cached to memory and small ones should be streamed
B - The small Ones should be cached and large one should be streamed
Answer : B
Explanation
When the small one is cached, each row from the larger table can be efficiently compared with each row of the small table.
Q 7 - The LIMIT clause applied to a select query
A - Executes the entire query before the LIMIT clause
B - Hive fetches one row at a time until it gets the required limit.
C - Creates a temporary file and stores the query result their
Answer : A
Explanation
The query is run on complete data set and then the results are restricted using LIMIT clause.
Q 8 - If a hive query produces unexpected result then its cause can be investigated by using
Answer : B
Explanation
Virtual columns give the complete path and name of data block from where the error is arising.
Q 9 - The explode() function in hive takes an array of input and iterates through it returning each element as a separate row. This is an example of
Answer : C
Explanation
SELECT explode(array(1,2,3)) AS element FROM src;
gives 1 2 3 so it is table generating function
Q 10 - To add a new user defined Function permanently to Hive, we need to
A - Create a new version of HIve
B - Add the .class Java code to FunctionRegistry
Answer : B
Explanation
Functionregistry holds the list of all permanent functions
