Speeding Through Data: Apache Spark vs ClickHouse

Prakhar
6 min readDec 14, 2023

Introduction

In the dynamic world of data management, the quest for optimal speed and efficiency leads us to explore two formidable contenders: Apache Spark and ClickHouse. Picture it as a high-speed race where each platform vies for the coveted title of the fastest, most adept data processing solution.

Today, we embark on a journey to dissect these powerhouses, unraveling their unique capabilities, and differences in data processing methodologies, and uncovering the real story behind their remarkable speeds.

But that’s not all — beyond the Spark vs ClickHouse duel, we’ll draw parallels and distinctions between Spark, Python, and MySQL. For those pondering a transition, seeking similarities and differences among these data giants becomes paramount.

Is it a seamless transition, or are there roadblocks and diversions along the way? Join us as we navigate through the intricacies of speed, data processing techniques, and the intricate intersections of Spark, Python, and MySQL, shedding light on the paths for those considering a switch in their data management journey.

What is ClickHouse

ClickHouse emerges as a beacon of efficiency, promising lightning-fast analytics and unparalleled performance. But what exactly is ClickHouse?

ClickHouse isn’t just another database; it’s a column-oriented, open-source analytical database management system designed to process data at mind-boggling speeds. Engineered by the team behind Yandex, the Russian search engine giant.

ClickHouse was crafted to handle vast volumes of data with ease, delivering exceptional query performance for analytical workloads. ClickHouse stores data by columns rather than rows, optimizing query performance for analytical tasks like complex aggregations, data mining, and reporting.

Moreover, ClickHouse’s compatibility with various data formats and integration capabilities with popular analytics tools make it a formidable player in the data management landscape. Its support for SQL allows users to leverage their existing knowledge while harnessing the power of ClickHouse for advanced analytics and insights.

What is Apache Spark

In the vast landscape of big data processing, Apache Spark shines as a powerful, open-source, and lightning-fast engine, transforming the way we analyze and manipulate data. But what exactly is Apache Spark, and why has it become the go-to choice for data engineers, analysts, and machine learning enthusiasts alike?

Developed at UC Berkeley’s AMPLab and later open-sourced, Spark has revolutionized the data processing paradigm by offering a unified engine that supports various data processing tasks.

Apache Spark isn’t merely a tool; it’s a robust distributed computing framework designed to handle immense volumes of data with unparalleled speed and efficiency.

One of Spark’s defining features is its resilience and fault tolerance, attributed to its ability to efficiently manage data across distributed clusters. This fault tolerance ensures data consistency and reliability, even in the event of node failures, making it a robust choice for mission-critical applications.

But beyond its processing power, Spark’s ecosystem shines with a plethora of libraries like Spark SQL, MLlib, GraphX, and Streaming, empowering users to perform advanced analytics, machine learning, graph computations, and real-time data streaming — all under one unified framework.

In summary, Apache Spark isn’t just about speed; it’s a versatile, scalable, and developer-friendly data processing framework that elevates the possibilities of what can be achieved with big data. Its combination of speed, versatility, and comprehensive toolset positions it as an indispensable tool in the data scientist’s toolkit, fueling innovation and accelerating insights.

Spark Vs ClickHouse

Architecture:

  • ClickHouse: It is a columnar-oriented database management system specifically designed for OLAP (Online Analytical Processing) workloads. ClickHouse excels at performing fast analytics on large volumes of data by storing data in a columnar format, which allows for highly efficient query execution for analytical queries.
  • Apache Spark: Spark is a distributed computing framework that provides in-memory processing capabilities. It supports various workloads, including batch processing, real-time stream processing, machine learning, and graph processing. Spark’s core abstraction is the resilient distributed dataset (RDD), which allows parallel processing and fault tolerance.

Use Cases:

  • ClickHouse: It is primarily used for OLAP queries, data warehousing, and analytics where fast query execution on vast amounts of data is essential. ClickHouse is suitable for scenarios requiring high-speed analytical queries and aggregations over large datasets.
  • Apache Spark: Spark is a versatile framework used for a wide range of applications, including ETL (Extract, Transform, Load), data streaming, machine learning, graph processing, and real-time analytics.

Data Processing Model:

  • ClickHouse: It employs a columnar storage model where data is stored and processed by columns, which enables efficient compression and retrieval of specific columns.
  • Apache Spark: Spark utilizes an in-memory processing model. It can process data in batch or streaming modes and provides a more generalized approach to data processing, allowing users to build complex data pipelines and perform various operations on data.

Scalability and Performance:

  • ClickHouse: It is highly optimized for analytical queries and can handle large-scale data efficiently. ClickHouse achieves exceptional query performance due to its columnar storage, data compression techniques, and efficient query execution engine.
  • Apache Spark: Spark is designed for horizontal scalability and can scale out across a cluster of machines. It provides in-memory computation, which can significantly enhance performance for iterative algorithms and interactive data analysis.

Spark Basics

Now that we know what spark is and how it’s different or similar to ClickHouse let’s see its basic coding snippets

  1. Initializing Spark Session:

This is a local deployment option, used for testing and development.

from pyspark.sql import SparkSession

# Initialize Spark session
spark = SparkSession.builder \
.appName("MySparkApp") \
.getOrCreate()

2. Loading Data and Creating DataFrame:

# Read data from a CSV file and create a DataFrame
df = spark.read.csv("file_path.csv", header=True, inferSchema=True)

3. Performing Operations on DataFrame:

# Show the first few rows of the DataFrame
df.show()

# Select specific columns from the DataFrame
selected_df = df.select("column1", "column2")

# Filter data based on conditions
filtered_df = df.filter(df["column1"] > 100)

# Perform aggregation operations
aggregated_df = df.groupBy("column1").agg({"column2": "sum"})

Similarities

Spark and Python

Let’s see an example of how Python and Spark are similar. In this example, we are squaring a number.

# Python List Comprehension
numbers = [1, 2, 3, 4, 5]
squared_numbers = [x ** 2 for x in numbers]
print(squared_numbers)

Spark Equivalent to it would be

# Spark DataFrame Transformation
from pyspark.sql.functions import col

# Assuming 'df' is a DataFrame
squared_df = df.select(col("column") ** 2)
squared_df.show()

Spark and MySQL

Example 1

Here we will demonstrate how MySQL and Spark are similar. It is a query that performs SUM() operation

-- MySQL Query
SELECT product_id, SUM(quantity_sold) AS total_quantity, SUM(revenue) AS total_revenue
FROM sales_data
GROUP BY product_id;

Spark Equivalent to it would be

from pyspark.sql import SparkSession
from pyspark.sql.functions import col

# Perform operations on imc_transactions DataFrame...
# Initialize Spark session
spark = SparkSession.builder \
.appName("MySQL_Spark_Similarity") \
.getOrCreate()

# Read your data into a DataFrame (example: reading from a file)
data_df = spark.read.format("csv").option("header", "true").load("path_to_your_data.csv")

# Register the DataFrame as a temporary view
data_df.createOrReplaceTempView("table_name")

# Now you can access this table using spark.table()
imc_transactions = spark.table("table_name")

# Assuming 'sales_df' is a DataFrame
selected_agg_df = imc_transactions.groupBy("product_id") \
.agg({"quantity_sold": "sum", "revenue": "sum"}) \
.withColumnRenamed("sum(quantity_sold)", "total_quantity") \
.withColumnRenamed("sum(revenue)", "total_revenue") \
.select("product_id", "total_quantity", "total_revenue")

selected_agg_df.show()

As we can see they are similar in logic only difference is that it looks daunting but it is relatively fine.

Example 2

SELECT column1, SUM(column2) AS total_sum
FROM table_name
WHERE column1 > 100
GROUP BY column1;

Spark Equivalent to it would be

# Spark DataFrame SQL-like Operation
selected_agg_df = df.filter(df["column1"] > 100)\
.groupBy("column1")\
.agg({"column2": "sum"})\
.withColumnRenamed("sum(column2)", "total_sum")\
.select("column1", "total_sum")

selected_agg_df.show()

Example 3

Now let’s jump into a little complex problem. In this problem, we will add more filters and a Date Formatting into the SELECT statement

SELECT 
DATE_FORMAT(payment_added_on,'%Y-%m') AS DDate,
COUNT(payment_id) AS Total_Courses_Sold, COUNT(DISTINCT mem_id) AS Unique_PPC_Sold
FROM
transactions
WHERE
status = 2 and course_type_id = 31 and payment_amount != 1
GROUP BY
DDate

Spark Equivalent to it would be

# Assuming you have a DataFrame registered as a temporary view
transaction = spark.table("transactions")

# Perform the query using Spark SQL
result = transaction \
.filter((col("payment_status") == 2) &
(col("course_type_id") == 31) &
(col("payment_amount") != 1) \
.select(date_format("transaction_added_on", "yyyy-MM").alias("DDate"),
count("payment_id").alias("Total_Courses_Sold"),
countDistinct("customer_id").alias("Unique_Course_Sold")) \
.groupBy("DDate") \
.agg(count("payment_id").alias("Total_Courses_Sold"),
countDistinct("mem_id").alias("Unique_PPC_Sold"))

# Show the result
result.show()

# Stop Spark session
spark.stop()

Conclusion

In the domain of analysis, Apache Spark stands out with its versatile toolkit. Its in-memory computing and diverse libraries, including Spark SQL and MLlib, offer robust capabilities for deep insights across various app data facets.

However, ClickHouse’s lightning-fast query performance and efficiency in handling extensive datasets make it a standout choice for immediate feedback on course popularity, rapid sales trend evaluation, and swift assessments of marketing strategies.

The decision boils down to priorities: Spark for detailed exploration and machine learning, ClickHouse for swift, time-sensitive evaluations.

Ultimately, by aligning the strengths of either solution with your specific needs — be it detailed analysis or immediate insights — you can harness the power of data to propel your app’s success.

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Prakhar

A Curious guy ready to get his hands dirty in data pool