A data scientist working with medical claims data faced memory issues when merging large datasets. With 64GB of RAM, the datasets, which are extremely sparse, resulted in over 100 million rows after merging. The Jupyter notebook kernel crashed due to insufficient memory. Dask, a tool designed for handling data that doesn’t fit into memory, was employed. The data was read from CSV files, repartitioned for Dask, and intermediate results were saved as Parquet files to manage memory. Despite these efforts, the final merge still caused a crash. The process involved reading 11 CSV files, merging them step-by-step, and saving intermediate results to disk to free up memory. However, the last merge step overwhelmed the system, suggesting a need for alternative tools or strategies for handling such large-scale data operations.
Source: stackoverflow.com
