In today’s data-driven world, managing large datasets efficiently is crucial for maintaining performance and ensuring seamless operations. One way to achieve this is through data partitioning. In this post, we’ll explore how I handle New York taxi data spanning from 2016 to 2018 using partitioning to optimize performance and storage.
What is Data Partitioning?
Data partitioning involves dividing large datasets into smaller, manageable pieces. When working with millions of rows of data, partitioning by a key attribute, like date, helps maintain efficiency when querying and analyzing data.
In this example, I’ve been working with data from 2016, 2017, and 2018. With each year containing millions of rows, a partitioning strategy becomes essential.
The Traditional Approach
In the past, I would start by creating a dataflow, pulling data from the main source, and applying a filter by date. For example, I filtered data to capture only the records from 2016. After fetching the data, it would be sent to a lakehouse, which served as a storage layer. Eventually, I would append the data for 2016, 2017, and 2018 to get a full, comprehensive view.
This method works well, but I recently discovered a more efficient way.
A More Streamlined Method
The first step in the new approach is creating a data pipeline. Here’s how it’s done:
1. Set Up a Data Pipeline: In my workspace, I created a new data pipeline using the “copy data” method. This approach allows me to ingest data seamlessly.
2. Partition by Date: I named the task “Taxi Data 2016” and selected the source for my data. I wrote SQL code to partition the data by date, pulling only the records from 2016.
3. Store the Data: Once partitioned, I sent the data to the lakehouse, creating a new table named “NYC_Taxi_Data.”
4. Repeat for Subsequent Years: I repeated the same process for 2017 and 2018, adjusting the SQL queries accordingly.
This systematic approach ensures that data is ingested efficiently, year by year, and stored in the lakehouse.
Avoiding Data Duplication
One potential issue with this method is that when appending new data (e.g., adding 2019 or 2020 later), the data for 2016 through 2018 will duplicate because it keeps adding on top of itself. To avoid this, I added one final step: creating a notebook.
Creating a Notebook to Prevent Duplication
Here’s how I set up a notebook to ensure data integrity:
2. Writing the SQL Statement: Reference the lakehouse as the data source then set the notebook’s language to Spark SQL. Now, you can write the SQL statement to drop the table if it already exists.
3. Incorporate the Notebook into the Pipeline: I added this notebook to the beginning of the pipeline to ensure that, before data ingestion starts, the old table is dropped. This prevents any duplication during the appending process.
The Final Workflow
Once everything was set up, my pipeline worked like this:
Conclusion
Partitioning data by date and using a structured data pipeline helps improve efficiency. By adopting this streamlined approach, I’ve been able to manage large datasets more effectively and maintain performance.
Partitioning is an incredibly powerful technique, especially when working with massive datasets like taxi records. By ensuring efficient data management and preventing duplication, you can maintain the integrity of your data while also keeping processes smooth and optimized.
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