The Questions That You May Be Asked During a Hive Interview
Are you going to sit for an interview for having a job as a Hive expert? If you are then you may be nervous about facing the interview. It is the same for all. Whenever we try for an interview, we feel nervous and that does not depend on the level of preparation that we have. If you are nervous then you are in the right place. If you continue reading then you will be able to know the Hive Interview Questions that we may be asked. As you will be able to understand the nature of questions that you may be asked you can prepare for the interview better and can be the one who is selected for the job.
Let us see a number of the questions that you may face through such an interview. We have made sure to include the probable answers also so after understanding through this you feel that you are more equipped than the being who will be interviewing you.
What is Hive?
This may be the first question that you may be asked. I am sure you know the answer as your study is related to this field. But then also to be certain that we know the real answer that you must give. The answer should be that it is a creation made by those working on Facebook which allows one who is more or less efficient with SQL to write Hive Query Language. It is somewhat similar to conventional database code which has SQL admittance.
What can you tell about the present version of HIVE and explain the ACID transactions?
This may be the next Hive Interview Questions. You may be also knowing this answer but for the benefit of others and for you to ascertain whether you know the right answer, let us know the answer that should be given. The present version of HIVE that we can use is 0.13.1. Now you may be thinking about how to tackle the next part of the question. The answer is easy. ACID is the short form of Atomicity, Consistency, Isolation, and Durability. These natures of dealings are provided at the row levels. The transactions are:
Can you explain HIVE variable? Explain also why we use it.
This is the next question that is asked by the interviewer. I know you are prepared and you may be thinking how easy the interview is going to be. HIVE variable is generally created within the environment of HIVE which is referenced by the scripting languages of HIVE. The reason of using this methodology is to pass a quantity of values onto the queries when there is working with the query. The source command is used by this methodology.
Explain the nature of data warehouse suitable for HIVE? Also explain the nature of tables that you can use in HIVE?
Are you confused by hearing this one amongst the Hive Interview Questions? If you are so then just continue reading your confusion will be removed and you will know the correct answer. HIVE is not looked upon as a full database. There are some restrictions that are put in place by Hadoop and HDFS. The restrictions are put in place by the rules and regulations of design. HIVE is not suitable for all the nature of data warehouse applications. It is only applicable to use HIVE where there is large database. But in the below nature of the database it is not recommended to use HIVE:
- For analyzing static database
- The response time is less
- There is no rapid change in data.
There are only two types of tables that is used in HIVE. The tables are:
- Managed table
- External table
How can we change the HIVE settings?
Yes, we can definitely change the settings in HIVE within the sessions. For this we need to use the SET command. This helps us for changing the settings for the exact query.
Name the components that are used in HIVE processor?
This may be the next question which your interviewer may be asking with a stubborn face. Yes, it is obvious that you know the answer. But then also to have it consolidated in one place, the components are:
- Logical and Physical plan of generation
- Engine for execution
- UDAF and UDF
- Type checking
- Semantic analyzers
Can you mention the string data size that can be handled by HIVE?
You may be thinking what a question to ask. The answer can be given by anyone. Yes, it can be but then also to make others understand it is better to jot down that over here. The answer is:
The utmost size of string data type that can be supported by HIVE is 2 GB.
HIVE can support by default the text file format. It also supports the Sequence files in binary format, ORC files, Files of Avro Data, and Parquet files.
Explain the function of Object inspector?
Ah now you are confused. There is nothing to be so. As you are in this place you will know the best answer before you sit in the hot seat. The answer is that Object inspector is that which helps in analyzing the interior arrangement of row object and also the individual arrangement of columns. By using this you can have a uniform way of accessing objects that are complex in nature and then those can be stored in different formats within the memory. It also helps us to know the structure of objects and it also gives us access to the internal fields that are inside the object.
Can UNIX shell be run from HIVE?
Yes, we can definitely run UNIX shell commands from Hive using the exclamation mark before the command that we use. If we write!pwd HIVE will list the directory that is currently running.
Explain the usage of Hcatalog?
Do you know the answer? This may be the next question that is asked from the Hive Interview Questions. The answer is given below so that you can refresh your memories.
By using this methodology you can share data with external systems. It gives access to the Hive meta store and other related tools so that data can be written on the data warehouse.
I think the concept is clear in your mind and you can be able to convenience the interviewer about this.
Can you create various tables for the same data in HIVE?
This is the next bomb shell that the interviewer asks. The answer is quite simple. HIVE creates schema and append upon a data file that is existing. Using HIVE you can have different schema for a single data file. This schema will be saved in the meta store and the data that was used will not be parsed in the given schema. As we will try to bring out the data schema will be used.
What is HIVE variable?
Yes, it is an easy question. But it may sound difficult to some. So let us know the answer to this also. The answer is: The hive variable is variable that is shaped in the environment of HIVE. It can be called upon by HIVE scripts. It can be used to convey some value to the queries of HIVE when the query is working.
Explain distributed cache?
- This is the facility that is provided by the Map Reduce feature. It is that which makes available the files that are needed to work upon at the time when a job is executed.
Explain the relationship that is between job and task?
- You may be thinking they both are similar. No, they are not in Big data. A job in Hadoop is divided into parts which are called tasks.
When to use Hive?
Thinking what to answer. There is nothing to think here is the answer that you need to make.
- Hive is helpful when creation of data warehouse applications are involved
- It is helpful if you are working with stationary data as a substitute for active data
- If you are working with data that is of high latency then also you will find the hive to be useful.
- If you have to maintain a data set that is large then you require Hive.
- If you are utilizing queries in place of scripting then you must be using Hive. When we are using queries instead of scripting
What is the comparison between HDFS and NAS?
Another bombshell, are you looking at this question in this manner. There is nothing to worry about just continuing reading and you will understand what you need to answer. First, you have to explain HDFS and NAS and then you can compare the features that they are made of.
- NAS is a data storage server that is connected to a network of computers that enables the assorted group of clientele access to data. This can be hardware and also can be software. Now HDFS which is a file system distributed in nature and it stores the required data in commodity hardware.
- Data stored in HDFS is distributed along all the computers that are in the network while in NAS the storage is made in hardware is specially dedicated for this purpose.
- Both of them work using MapReduce Program but in HDFS computation is associated with the data and in NAS the data is kept separate from the computation.
- HDFS is cost-effective as there is the usage of commodity hardware but NAS is costly comparatively as it uses a dedicated server for this purpose.
- I think after reading this answer you can clearly explain to your interviewer why you should be the one who should be given the job and no one else.
Explain what is SMB Join in HIVE?
This is the next from the Hive Interview Questions. There may be some who would like to know the answer so here is the answer for them. In SMB join in Hive, each one who is using a map can read a bucket from the table and the equivalent container from the next table and then can perform a join. Sort Merge Bucket is the full form of SMB. When it is used there is no limitation on the number of files that can be used and the number of joins that can be made. It is best to use SMB where there is the involvement of a larger table. One thing that is to be noticed is that when creating a join the tables that are used should have the same number of columns.
There might be lots of questions that can be asked in such a difficult interview. However, the above questions are the ones which are generally asked in such interviews.
Being ready with these sorts of Hive Interview Questions you will have the fundamental confidence and attitude so that you are the person who will certainly be the one chosen for the job. The thing that you must do is to make sure that you face up to the questioner with the level of confidence so they sense that you systematically understand HIVE. While answering a single question give a suitable reply in such a frame, that there is nothing else to say about that particular question.
It must be said that there is uncertainty linked with interviews but if you can make sure that you do your homework properly before going for an interview you will be able to face that with more confidence. Never show your nervousness or confusion to the interviewer. They may twist the words in such a manner that simple questions may seem difficult. Keep a cool head and think about the question and then answer that. It can easily be said you know all about HIVE so, you can answer any question that is thrown at you by the interviewer.