PySpark SQL vs DataFrames: What’s the Difference?

Apache Spark is a powerful open-source framework designed for fast and scalable computation across distributed systems. Among its many libraries, PySpark stands out as one of the most widely used, bringing the full potential of Spark’s distributed computing capabilities to Python developers.

PySpark provides a Python-friendly API that allows developers to utilize Spark’s power for big data processing and analytics. It enables users to work with large-scale structured data easily and efficiently using Python programming.

When working with structured data in PySpark, there are two primary approaches available:

• PySpark SQL API
• PySpark DataFrame API

Both APIs offer powerful tools for processing and analyzing large datasets, but they cater to different use cases and user preferences.

In this article, we’ll explore the key differences between PySpark SQL API and PySpark DataFrame API, their benefits, and when to use each — helping you choose the right approach for your PySpark projects.

Key Points –

• PySpark provides two powerful ways to process structured data — SQL API and DataFrame API.
• SQL API allows you to write SQL queries directly within PySpark using the sql() method.
• DataFrame API offers a Python-friendly approach with methods like select(), filter(), groupBy(), and more.
• DataFrames in PySpark are distributed across the cluster for faster parallel processing.
• SQL API is best suited for users coming from SQL or database backgrounds for simple and ad-hoc queries.
• DataFrame API is perfect for complex data transformations, advanced logic, and chaining multiple operations.
• You can easily mix SQL API and DataFrame API in a single PySpark application — convert DataFrames to SQL views and vice versa.
• Temporary views created from DataFrames using createOrReplaceTempView() allow SQL queries to run on DataFrame data.
• The output of an SQL query returns a DataFrame, enabling further transformations using the DataFrame API.
• Mastering both APIs makes your PySpark skills complete — giving you flexibility, scalability, and efficiency in handling large-scale data.

What is PySpark SQL API?

PySpark SQL is one of the most essential and widely used modules in PySpark that allows working with structured data efficiently. It enables developers to write SQL queries within Spark applications, making data processing simple and familiar for those coming from a SQL background.

The pyspark.sql module allows you to perform SQL-like operations on large datasets stored in Spark memory. You can either write SQL queries just like traditional relational databases (RDBMS) or use the PySpark DataFrame API for programmatic data manipulation. PySpark SQL supports combining both approaches — for example, running SQL queries and then applying DataFrame transformations on the result.

# Create temporary table
# Import SparkSession
from pyspark.sql import SparkSession

spark = SparkSession.builder.appName("sparkbyexample").getOrCreate()

# Creating DataFrame
data = [("Sai", 28), ("Ram", 33), ("Geetha", 25)]
columns = ["Name", "Age"]

df = spark.createDataFrame(data, columns)

# Registering DataFrame as SQL temporary view
df.createOrReplaceTempView("people")

# Running SQL query
result = spark.sql("SELECT * FROM people WHERE Age > 30")
result.show()

This yields the output below.

# Output:
+----+---+
|Name|Age|
+----+---+
| Ram| 33|
+----+---+

What is PySpark Data Frame API?

A PySpark DataFrame is a distributed collection of data organized into rows and columns (just like a table in a relational database or a DataFrame in R/Python). What makes it powerful is that it comes with the scalability and performance benefits of Apache Spark.

In PySpark, DataFrames are distributed across multiple machines in a cluster. This means any operation performed on a DataFrame runs in parallel on different nodes, allowing for faster processing of large datasets without manual handling of data distribution.

# DataFrame API to select columns using where()
result = df.select("Name", "Age").where(df.Age > 30)
result.show()

This yields the output below.

# Output:
+----+---+
|Name|Age|
+----+---+
| Ram| 33|
+----+---+

PySpark SQL vs DataFrame: A Head-to-Head Comparison

Benefits of Using PySpark SQL API

PySpark SQL API is a great starting point for users who are already comfortable with SQL. It offers simplicity and readability, and makes querying big data feel like working with a traditional database.

• SQL Familiarity

If you already know SQL, working with PySpark SQL feels natural. Data Analysts, DBAs, and anyone coming from a database background can start analyzing big data without learning new syntax.

Example:

# Run SQL Query to Group by Department and Count Employees
from pyspark.sql import SparkSession

# Creating Spark Session
spark = SparkSession.builder.appName("sparkbyexample").getOrCreate()

# Sample Data
data = [("Sai", "HR"), ("Ram", "IT"), ("Geetha", "HR"), ("John", "IT"), ("Latha", "Finance")]
columns = ["Name", "Department"]

# Creating DataFrame
df = spark.createDataFrame(data, columns)

# Registering DataFrame as SQL temporary view
df.createOrReplaceTempView("employees")

# Running SQL query for Group By and Count
result = spark.sql("""
    SELECT Department, COUNT(*) AS total_employees
    FROM employees
    GROUP BY Department
""")

result.show()

Yields below output.

# Output:
+----------+---------------+
|Department|total_employees|
+----------+---------------+
|        HR|              2|
|        IT|              2|
|   Finance|              1|
+----------+---------------+

• Ad-Hoc Queries Made Easy:

PySpark SQL is perfect for quick, one-time queries or data exploration. You don’t need to write complex code — just write SQL statements directly and get the output fast.

• Readable & Declarative Style:

SQL is declarative — meaning you describe what you want, not how to get it. This makes SQL queries highly readable and easier to maintain, especially for teams.

• Seamless Integration with BI Tools:

Many Business Intelligence (BI) tools like Tableau, Power BI, and Qlik work smoothly with SQL queries. PySpark SQL makes it easier to connect Spark with these tools for dashboards and reporting.

Benefits of Using PySpark DataFrame API

While PySpark SQL focuses on simplicity, the DataFrame API offers greater control, flexibility, and integration with Python’s rich ecosystem.

• Powerful Data Transformations:

• The DataFrame API is ideal for handling complex data processing tasks like:
• Multi-level joins
• Grouping and aggregations
• Applying User-Defined Functions (UDFs)
• Data cleansing and manipulation

Example:

#  Grouping by Department and Counting Employees
from pyspark.sql import SparkSession
from pyspark.sql.functions import count

# Creating Spark Session
spark = SparkSession.builder.appName("sparkbyexample").getOrCreate()

# Sample Data
data = [("Sai", "HR"), ("Ram", "IT"), ("Geetha", "HR"), ("John", "IT"), ("Latha", "Finance")]
columns = ["Name", "Department"]

# Creating DataFrame
df = spark.createDataFrame(data, columns)

# Grouping by Department and Counting Employees
result = df.groupBy("Department").agg(count("*").alias("total_employees"))

result.show()

This yields the output below.

# Output:
+----------+---------------+
|Department|total_employees|
+----------+---------------+
|        HR|              2|
|        IT|              2|
|   Finance|              1|
+----------+---------------+

• Native Python Experience:

The DataFrame API fits naturally into Python programming. It supports functional programming styles like chaining methods, lambda functions, and integrating with Python’s syntax.

• Type-Safety and Early Error Detection:

Unlike SQL, where errors might show up only at runtime, the DataFrame API often catches mistakes early — like missing columns, wrong data types, or incorrect functions — making debugging easier.

• Easy Integration with Python Libraries

Since the DataFrame API is code-based, it integrates beautifully with popular Python data science libraries like:

• pandas
• NumPy
• Matplotlib
• seaborn
• scikit-learn

This makes PySpark DataFrame API a perfect fit for data engineers and data scientists.

When to Use PySpark SQL API

• Your Team is More Comfortable with SQL:

If your team comes from a SQL or database background (like Data Analysts, DBAs, BI developers), then using SQL syntax feels more natural and faster.

• Building Dashboards or Quick Data Profiling:

SQL API is perfect for running quick queries, data exploration, summarizing reports, or validating data directly using simple SQL commands.

Use case:

• Quick COUNT, SUM, GROUP BY
• Data validation
• Ad-hoc querying

• Easy Integration with BI Tools:

Most BI tools like:

• Tableau
• Power BI
• Apache Superset
  support direct SQL querying.

Hence, using SQL API makes your data models BI-friendly and easier to maintain.

When to Use PySpark DataFrame API

• Complex ETL Pipelines:

DataFrame API is more powerful and flexible when you are writing multi-step data transformations like:

• Building reusable data pipelines
• Filtering
• Aggregations
• Window functions
• Joining multiple tables

• Prefer Python Over SQL:

If your team loves Python coding style and functional programming (map, filter, reduce), DataFrame API blends naturally with that.

DataFrame API makes it easy to integrate Spark output with:

• Integrating with Python Libraries:

DataFrame API makes it easy to integrate Spark output with:

• pandas
• NumPy
• matplotlib
• scikit-learn
• user-defined functions (UDFs)

This is very useful in machine learning pipelines, data science workflows, or custom logic scenarios.

Combine Both SQL API and DataFrame API

PySpark allows to combine both SQL API and DataFrame API in your data processing workflow. This flexibility makes PySpark very powerful, you can use the simplicity of SQL queries to fetch the data and then use the rich DataFrame API to perform further transformations or analysis.

# Combine both sql ApI and DataFrame API
from pyspark.sql import SparkSession

# Creating SparkSession
spark = SparkSession.builder.appName("sparkbyexample").getOrCreate()

# Creating a DataFrame
data = [("Sai", 28), ("Ram", 33), ("Geetha", 25)]
columns = ["Name", "Age"]

df = spark.createDataFrame(data, columns)

# Registering DataFrame as a temporary SQL view
df.createOrReplaceTempView("people")

# Running SQL query using SQL API
result = spark.sql("SELECT * FROM people WHERE Age > 30")

# Showing the result from SQL query
result.show()

# Further transforming the result using DataFrame API
final_result = result.select("Name").withColumnRenamed("Name", "Person_Name")

# Showing the final transformed result
final_result.show()

This yields the output below.

# Output:
+----+---+
|Name|Age|
+----+---+
| Ram| 33|
+----+---+

+-----------+
|Person_Name|
+-----------+
|        Ram|
+-----------+

Frequently Asked Questions of PySpark SQL vs DataFrames

Conclusion

In this article, I have explained how PySpark provides developers with the flexibility to handle structured data efficiently using both SQL API and DataFrame API. The SQL API is ideal for writing quick and simple queries using familiar SQL syntax. The DataFrame API is more powerful when working with complex transformations, Python integration, and advanced data operations.

The real advantage of PySpark comes from the ability to combine both APIs seamlessly, allowing you to run SQL queries on your data and further process the results using DataFrame operations.

Mastering both SQL and DataFrame APIs not only improves your data processing skills but also helps you build scalable, maintainable, and production-ready data pipelines, making you a well-rounded and effective PySpark developer.

Happy Learning!

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• Top 10 PySpark Interview Questions
• PySpark vs Pandas: Key Differences
• PySpark UDF Explained with Examples