When designing a data lake or lakehouse storage standard.
Data Lake File Format Selection AI Prompt
This prompt helps select the right file and table formats for a lake or lakehouse based on workloads, engines, and update requirements. It is especially valuable when teams need to choose between plain file formats and ACID table formats for different layers. The response should clearly separate storage format from table-management capabilities.
Select the right file format and table format for each layer of this data lake.
Workloads: {{workloads}} (batch analytics, streaming, ML feature engineering, etc.)
Platform: {{compute_engines}} (Spark, Trino, Dremio, BigQuery, etc.)
1. File format comparison:
Parquet:
- Columnar, splittable, highly compressed
- Best for: analytical reads, column-selective queries, broad engine support
- Limitations: no ACID transactions, no efficient row-level updates, schema evolution is limited
- Choose when: read-heavy analytics, stable schemas, no need for row-level changes
ORC:
- Similar to Parquet, marginally better for Hive workloads
- Choose when: primary engine is Hive or Hive-compatible
Avro:
- Row-based, schema embedded in file, excellent schema evolution support
- Best for: streaming ingestion, schema-registry integration, write-heavy workloads
- Choose when: Kafka → data lake ingestion, schema evolution is frequent
Delta Lake / Apache Iceberg / Apache Hudi (table formats):
- ACID transactions, time travel, schema evolution, row-level deletes
- Delta: tightest Spark integration, best for Databricks
- Iceberg: broadest engine support (Spark, Trino, Flink, Dremio, BigQuery), best for multi-engine lakes
- Hudi: streaming-optimized, best for CDC and near-real-time use cases
2. Recommendation by layer:
- Bronze (raw ingest): Parquet or Avro depending on source
- Silver (cleansed): Delta or Iceberg (need row-level updates for SCD)
- Gold (marts): Delta or Iceberg (need ACID for concurrent writes)
3. Compression codec recommendation:
- Snappy: fast compression/decompression, moderate compression ratio (default)
- Zstd: better compression ratio than Snappy at similar speed (preferred for cold storage)
- Gzip: maximum compression, slow decompression (use only for archival)
Return: format selection matrix, recommendation per layer, and compression codec guide.When to use this prompt
When supporting multiple compute engines over the same data.
When deciding between Parquet, Avro, Delta, Iceberg, or Hudi.
When compression choices affect performance and storage cost.
What the AI should return
Return a format-selection matrix, layer-by-layer recommendation, and codec guide. Explain trade-offs for analytics, streaming, schema evolution, and row-level updates. The output should tell the reader what to use in Bronze, Silver, and Gold, and why.
How to use this prompt
Open your data context
Load your dataset, notebook, or working environment so the AI can operate on the actual project context.
Copy the prompt text
Use the copy button above and paste the prompt into the AI assistant or prompt input area.
Review the output critically
Check whether the result matches your data, assumptions, and desired format before moving on.
Chain into the next prompt
Once you have the first result, continue deeper with related prompts in Infrastructure and Platform.
Frequently asked questions
What does the Data Lake File Format Selection prompt do?+
It gives you a structured infrastructure and platform starting point for data engineer work and helps you move faster without starting from a blank page.
Who is this prompt for?+
It is designed for data engineer workflows and marked as intermediate, so it works well as a guided starting point for that level of experience.
What type of prompt is this?+
Data Lake File Format Selection is a single prompt. You can copy it as-is, adapt it, or use it as one step inside a larger workflow.
Can I use this outside MLJAR Studio?+
Yes. The prompt text works in other AI tools too, but MLJAR Studio is the best fit when you want local execution, visible Python code, and reusable notebooks.
What should I open next?+
Natural next steps from here are Compute Sizing Guide, Platform Evaluation Chain, Warehouse Cost Optimization.