Apache Presto Interview Questions for freshers experienced :-
1. What is Presto?
Presto is a distributed SQL query engine. It is an open source software project to develop a database.
2. What are the features of Presto?
There are following features of Presto:
- It is simple to use.
- It provides pluggable connectors.
- It provides pipelined executions.
- It provides user define functions.
3. What are the Presto applications?
There are various Presto applications:
- Teradata
- Airbnb
4. Why should we use Presto?
We should use Presto because of its features:
- It supports standard ANSI SQL.
- It is built in Java.
- It has connector architecture that is Hadoop.
- It runs on multiple Hadoop distributions.
5. What are the components of Presto architecture?
Presto architecture components are given below:
- Client : Clint submits SQL statements to a coordinator to get the result.
- Coordinator: It parses the SQL queries.
- Connector : Storage plugin is called as connectors.
- Worker : It assigns task to worker nodes.
6. What are the log files of the Presto server?
The logs files of the Presto server are given below:
- Launcher.log
- Server.log
- http-request.log
7. What is Presto verifier?
Presto verifier is used to test Presto against another database (such as MySQL).
8. What is the default port of Presto?
The default port of Presto is 8080.
9. What are the Config properties of Presto?
The Config properties of Presto are given below table:
Config Properties—–>Descriptiontask.
info -refresh-max-wait:It reduces coordinator work load.
Task.max-worker-threads:It splits the process and assigns to each worker nodes.
distributed-joins-enabled:It is Hashed based distributed joins.
node-scheduler.network-topology:It sets network topology to scheduler.
10. What are the various data types in Presto?
In Presto, there are various data types in Presto.
- Varchar
- Bigint
- Double
- Decimal
- Json etc.
11. What are the functions of Presto?
There are various functions of Presto that are given below:
Function—>Description
Abs(x):It returns the absolute value of X.
Cbrt(x):It returns the cube root of x.
Ceiling(x):It returns the x value rounded up to nearest integer.
Ceil(x):Arial for ceiling(x)
Log2(x):It returns the base 2 logarithm of x.
12. What is the use of MySQL Connector?
MYSQL Connector is used to query an external MySQL database.
13. How can we create table by using command?
We can create table by using command:
presto:tutorials> create table mysql.tutorials.sample as
select * from mysql.tutorials.author;
presto:tutorials> create table mysql.tutorials.sample as
select * from mysql.tutorials.author;
14. What is JMX Connector?
JMX stands for Java Management Extension. It gives information about the java virtual machine and software running inside JVM.
Apache Presto – Overview
Data analytics is the process of analyzing raw data to gather relevant information for better decision making. It is primarily used in many organizations to make business decisions. Well, big data analytics involves a large amount of data and this process is quite complex, hence companies use different strategies.
For example, Facebook is one of the leading data driven and largest data warehouse company in the world. Facebook warehouse data is stored in Hadoop for large scale computation. Later, when warehouse data grew to petabytes, they decided to develop a new system with low latency. In the year of 2012, Facebook team members designed “Presto” for interactive query analytics that would operate quickly even with petabytes of data.
What is Apache Presto?
Apache Presto is a distributed parallel query execution engine, optimized for low latency and interactive query analysis. Presto runs queries easily and scales without down time even from gigabytes to petabytes.
A single Presto query can process data from multiple sources like HDFS, MySQL, Cassandra, Hive and many more data sources. Presto is built in Java and easy to integrate with other data infrastructure components. Presto is powerful, and leading companies like Airbnb, DropBox, Groupon, Netflix are adopting it.
Presto − Features
Presto contains the following features −
- Simple and extensible architecture.
- Pluggable connectors – Presto supports pluggable connector to provide metadata and data for queries.
- Pipelined executions – Avoids unnecessary I/O latency overhead.
- User-defined functions – Analysts can create custom user-defined functions to migrate easily.
- Vectorized columnar processing.
Presto − Benefits
Here is a list of benefits that Apache Presto offers −
- Specialized SQL operations
- Easy to install and debug
- Simple storage abstraction
- Quickly scales petabytes data with low latency
- Presto − Applications
Presto supports most of today’s best industrial applications. Let’s take a look at some of the notable applications.
Facebook − Facebook built Presto for data analytics needs. Presto easily scales large velocity of data.
Teradata − Teradata provides end-to-end solutions in Big Data analytics and data warehousing. Teradata contribution to Presto makes it easier for more companies to enable all analytical needs.
Airbnb − Presto is an integral part of the Airbnb data infrastructure. Well, hundreds of employees are running queries each day with the technology.
Why Presto?
Presto supports standard ANSI SQL which has made it very easy for data analysts and developers. Though it is built in Java, it avoids typical issues of Java code related to memory allocation and garbage collection. Presto has a connector architecture that is Hadoop friendly. It allows to easily plug in file systems.
Presto runs on multiple Hadoop distributions. In addition, Presto can reach out from a Hadoop platform to query Cassandra, relational databases, or other data stores. This cross-platform analytic capability allows Presto users to extract maximum business value from gigabytes to petabytes of data.