Apache Spark Interview Questions for various topics.
Pivoting a string column on a PySpark DataFrame involves transforming unique values from that column into multiple columns. This is often used for reshaping data where observations are spread across multiple rows to a single row per entity with various features. Below is an example of how to achieve this in PySpark. Pivoting a String …
How to Pivot a String Column on PySpark DataFrame? Read More »
Yes, Apache Spark supports reading and writing files in GZIP format. Spark provides built-in support for various compression formats, including GZIP, which can be beneficial for reducing the storage requirements of large datasets and for speeding up the reading and writing processes. Compression is usually transparent in Spark, meaning you don’t need to manually decompress …
When working with large datasets, it’s common to partition data into smaller, more manageable pieces. Apache Spark supports reading partitioned data from Parquet files efficiently. Below is a detailed explanation of the process, including code snippets in PySpark, Scala, and Java. Reading a DataFrame from a Partitioned Parquet File PySpark To read a DataFrame from …
How to Read a DataFrame from a Partitioned Parquet File in Apache Spark? Read More »
Summing a column in a Spark DataFrame is a common operation you might perform during data analysis. In this example, I’ll show you how to sum a column using Scala in Apache Spark. We’ll use some simple data to demonstrate this operation. Summing a Column in a Spark DataFrame Using Scala First, you need to …
How to Sum a Column in a Spark DataFrame Using Scala? Read More »
Apache Spark is a distributed computing framework designed for processing large-scale data efficiently and quickly. It does this by dividing tasks among multiple nodes in a cluster, and it uses a combination of in-memory computing and directed acyclic graph (DAG) scheduling to optimize execution. Below, we explore the internal workings of Apache Spark in greater …
Changing the nullable property of a column in a Spark DataFrame is not straightforward because the schema of a DataFrame is immutable. However, you can achieve this by constructing a new DataFrame with an updated schema. This involves manipulating the schema itself and then creating a new DataFrame with the modified schema. Let’s break this …
How to Change the Nullable Property of a Column in Spark DataFrame? Read More »
When working with Apache Spark, you may encounter situations where you need to filter a DataFrame based on criteria defined in another DataFrame. This is often referred to as using a “denylist” or “blacklist” criteria. Let’s dive into how you can achieve this using PySpark. Steps to Filter a DataFrame Using a Denylist To demonstrate, …
How to Filter Spark DataFrame Using Another DataFrame with Denylist Criteria? Read More »
RDD, which stands for Resilient Distributed Dataset, is a fundamental data structure in Apache Spark. It was the primary abstraction that empowered Spark’s rapid data processing capabilities. Understanding RDD is crucial for effectively leveraging Spark’s potential for big data processing. Let’s delve into what RDD is, its role in Spark, and its significance. What is …
What is RDD in Spark? Uncover Its Role and Importance Read More »
Apache Spark offers advanced window functions to operate on a subset of rows, and two of the primary ways to define such subsets are with the `ROWS BETWEEN` and `RANGE BETWEEN` clauses. Both of these clauses are used within the context of window specifications but have different behaviors. Understanding the differences between them is crucial …
What is the Difference Between ROWS BETWEEN and RANGE BETWEEN in Apache Spark? Read More »
How to Trim a String Column in PySpark DataFrame? Trimming a string refers to removing leading and trailing whitespace from the string. In PySpark, the `trim` function from the `pyspark.sql.functions` module is used to trim string columns in a DataFrame. You can use the `trim`, `ltrim` (to remove left whitespace), and `rtrim` (to remove right …
How to Trim a String Column in PySpark DataFrame? Read More »
