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Delta
Delta Lake is an open-source storage layer that brings ACID transactions to Apache Spark and big data workloads. It sits on top of existing cloud storage systems like S3, ADLS, or GCS and adds transactional consistency and schema enforcement to your Parquet files.
Use Cases
Data Lakes with ACID Guarantees: Perfect for real-time and batch data processing in Data Lake environments.
Streaming + Batch Workflows: Unified processing with support for incremental updates.
Time Travel: Easy rollback and audit of data versions.
Upserts (MERGE INTO): Efficient updates/deletes on Parquet data using Spark SQL.
Slowly Changing Dimensions (SCD): Managing dimension tables in a data warehouse setup.
Technical Context
Underlying Format: Parquet
Transaction Log: _delta_log folder with JSON commit files
Operations Supported:
-MERGE
-UPDATE / DELETE
-OPTIMIZE / ZORDER
Integration: Supported in open-source via delta-rs, [Delta Kernel], and Delta Standalone Reader.
git clone https://github.com/gchandra10/python_delta_demo