🔬 Tidyverse Series – Post 12: Handling Big Data Efficiently with Arrow & Parquet Link to heading

🛠 Why Arrow & Parquet? Link to heading

Traditional file formats like CSV can be slow and inefficient when working with large datasets. The combination of Apache Arrow and the Parquet format provides a modern, high-performance solution for big data processing in R.

🔹 Why Use Arrow & Parquet? Link to heading

✔️ Faster than CSV for reading and writing large datasets
✔️ Columnar storage improves query performance
✔️ Multi-language interoperability (R, Python, SQL, etc.)
✔️ Works seamlessly with dplyr and database backends
✔️ Supports efficient in-memory operations with Apache Arrow

These technologies enable scalable data workflows in R without memory bottlenecks.


📚 Key Arrow & Parquet Functions Link to heading

Function Purpose
write_parquet() Save data in Parquet format
read_parquet() Load Parquet files efficiently
arrow::open_dataset() Query large datasets directly
as_arrow_table() Convert data frames to Arrow tables
collect() Retrieve query results as a tibble

These functions allow for faster data storage and retrieval while minimizing disk space usage.


📊 Example: Converting a Large CSV to Parquet Link to heading

Imagine we have a 10GB CSV file that takes too long to load into R. Using Parquet, we can reduce read time significantly.

➡️ Save a CSV as a Parquet file Link to heading

library(arrow)
library(readr)

df <- read_csv("large_data.csv")
write_parquet(df, "large_data.parquet")

Parquet is compressed, reducing storage size and improving I/O speed.

➡️ Read the Parquet file back into R Link to heading

df <- read_parquet("large_data.parquet")

✅ Loads in seconds instead of minutes and consumes less memory.


🚀 Querying Large Datasets with arrow::open_dataset() Link to heading

Instead of loading the entire dataset into memory, we can query only the relevant rows from a large dataset using open_dataset().

➡️ Query large Parquet datasets efficiently Link to heading

library(dplyr)

# Open the dataset
big_data <- open_dataset("data_directory/")

# Query specific rows without loading the full dataset
filtered_data <- big_data %>%
  filter(category == "Cancer") %>%
  select(sample_id, gene_expression) %>%
  collect()

✅ This avoids memory overload by fetching only the necessary data.


📉 Comparison: CSV vs. Parquet Performance Link to heading

File Type Load Time File Size Memory Usage
CSV 120s 10GB High
Parquet 5s 2GB Low

Parquet reduces load time by ~24x and file size by ~5x compared to CSV. 🚀


📌 Key Takeaways Link to heading

Arrow and Parquet provide a modern, scalable alternative to CSV for handling large datasets.
Columnar storage significantly boosts performance, especially for analytics workflows.
Interoperability allows seamless data exchange between R, Python, SQL, and big data platforms.
open_dataset() enables querying large datasets without loading them into memory.

📌 Next up: Tidyverse for Bioinformatics – Case Studies! Stay tuned! 🚀

👇 Have you used Arrow or Parquet in your workflow? Let’s discuss!

#Tidyverse #Arrow #Parquet #BigData #RStats #DataScience #Bioinformatics #OpenScience #ComputationalBiology