Cracking an interview is the most difficult task for your life. You usually tend to get scared by hearing this word as interview shapes your future in the company. However, with the help of our hive interview questions, it has become easier for you to just sit at home and prepare for the interviews. Our experts and professionals know what exactly the interviewers ask in the interview, and accordingly, prepare all the questions and answers that make it easier for you to crack the interview by convincing them.
Hive is a warehouse of data and a software solution created on top of Hadoop for offering data query functions and further analysis works. Hive provides a SQL-like interface to analyze the data stored in different databases and other file systems that can integrate with Apache Hadoop. It facilitates reading, writing, and analyzing huge datasets stored in the distributed storage spaces like SQL. It is basically an ETL application for the entire Hadoop ecosystem. If you know Hadoop programming language, then you can apply for a job in this field in any software companies.
There are two types. Managed table and external table. In managed table both the data an schema in under control of hive but in external table only the schema is under control of Hive.
No Hive does not provide insert and update at row level. So it is not suitable for OLTP system.
Alter Table table_name RENAME TO new_name
Using REPLACE column option ALTER TABLE table_name REPLACE COLUMNS ……
It is a relational database storing the metadata of hive tables, partitions, Hive databases etc
Depending on the nature of data the user has, the inbuilt SerDe may not satisfy the format of the data. SO users need to write their own java code to satisfy their data format requirements.
Hive is a tool in Hadoop ecosystem which provides an interface to organize and query data in a databse like fashion and write SQL like queries. It is suitable for accessing and analyzing data in Hadoop using SQL syntax.
Yes. The TIMESTAMP data types stores date in java.sql.timestamp format
There are three collection data types in Hive.
Yes, using the ! mark just before the command.
For example !pwd at hive prompt will list the current directory.
The hive variable is variable created in the Hive environment that can be referenced by Hive scripts. It is used to pass some values to the hive queries when the query starts executing.
Using the source command.
Hive> source /path/to/file/file_with_query.hql
It is a file containing list of commands needs to run when the hive CLI starts. For example setting the strict mode to be true etc.
The default record delimiter is ? \n And the filed delimiters are ? \001,\002,\003
The schema is validated with the data when reading the data and not enforced when writing data.
SHOW DATABASES LIKE ‘p.*’
With the use command you fix the database on which all the subsequent hive queries will run.
There is no way you can delete the DBPROPERTY.
set hive.mapred.mode = strict;
It sets the mapreduce jobs to strict mode.By which the queries on partitioned tables can not run without a WHERE clause. This prevents very large job running for long time.
This can be done with following query
SHOW PARTITIONS table_name PARTITION(partitioned_column=’partition_value’)
When we issue the command DROP TABLE IF EXISTS table_name
Hive throws an error if the table being dropped does not exist in the first place.
The data stays in the old location. It has to be moved manually.
ALTER TABLE table_name CHANGE COLUMN new_col INT BEFORE x_col
No. It only reduces the number of files which becomes easier for namenode to manage.
By using the ENABLE OFFLINE clause with ALTER TABLE atatement.
By Omitting the LOCAL CLAUSE in the LOAD DATA statement.
There are many opportunities in this field if you have the right expertise and knowledge. For you to become an expert in this field, you can pursue your career in this field, from which you can ensure to gather an adequate amount of knowledge and expertise. With the technological space growing day by day in the market, there are lots of opportunities and scopes improving in this field. Most of the companies are looking to hire people who know how to work on Hadoop and Hive. For a fresher, if you are getting an opportunity to join a firm, then you can get paid up to 6,000 dollars to 12,000 dollars per annum initially, while for the experienced ones, they can earn up to 50,000 dollars per annum.
If you want to become an expert in this field, then it’s important for you to learn the right procedures and gather a sufficient amount of knowledge. You can gather the same just by reading our Hive interview questions and answers.