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Category: Tutorials
What is Hadoop? Hadoop is an open-source, distributed computing framework that allows for the processing and storage of large datasets across a cluster of computers. It was created by Doug Cutting and Mike Cafarella and is now maintained by the Apache Software Foundation. History of Hadoop Hadoop was inspired by Google’s MapReduce and Google File…
To find the second-highest salary for each department in SQL? Here are multiple methods to find the second-highest salary for each department in SQL, using different approaches. 1. Using Correlated Subquery This approach involves using a subquery to find the highest salary for each department and then excluding it. The subquery in SQL statement: is…
String manipulation is a common task in data processing. PySpark provides a variety of built-in functions for manipulating string columns in DataFrames. Below, we explore some of the most useful string manipulation functions and demonstrate how to use them with examples. Common String Manipulation Functions Example Usage 1. Concatenation Syntax: 2. Substring Extraction Syntax: 3.…
Creating DataFrames in PySpark Creating DataFrames in PySpark is essential for processing large-scale data efficiently. PySpark allows DataFrames to be created from various sources, ranging from manual data entry to structured storage systems. Below are different ways to create PySpark DataFrames, along with interesting examples. 1. Creating DataFrames from List of Tuples (Manual Entry) This…