2.3. Data Transformation and Processing
First Principle: Data transformation and processing fundamentally involve cleaning, enriching, and structuring raw data into a format suitable for machine learning, optimizing data quality and feature readiness for model training.
Raw ingested data is rarely in a format ready for machine learning. It often needs extensive cleaning, transformation, and aggregation. This is where data processing services come in.
Key Concepts of Data Transformation & Processing for ML:
- ETL (Extract, Transform, Load): A common process in data warehousing and data lakes for moving data from various sources, transforming it into a clean and consistent format, and loading it into a target.
- Data Cleaning: Handling missing values, removing duplicates, correcting errors, normalizing data.
- Data Enrichment: Combining data from multiple sources, adding new features.
- Data Structuring: Converting unstructured or semi-structured data into a structured format (e.g., flat tables, feature vectors).
- Batch Processing: For large volumes of data processed periodically.
- Streaming Processing: For continuous, real-time transformations.
AWS Services for Data Transformation & Processing in ML:
- Batch ETL: AWS Glue, Amazon EMR, Amazon Athena.
- Streaming ETL: Kinesis Data Analytics, Spark Streaming.
- ML-Specific Data Prep: SageMaker Processing Jobs, SageMaker Data Wrangler.
Scenario: You have raw customer interaction logs in Amazon S3, structured customer demographic data in Amazon RDS, and real-time clickstream data in Kinesis Data Streams. You need to clean, combine, and transform these into features suitable for an ML model.
Reflection Question: How do data transformation and processing services (e.g., AWS Glue for batch ETL, Kinesis Data Analytics for streaming, SageMaker Data Wrangler for ML-specific prep) fundamentally enable cleaning, enriching, and structuring raw data into a format suitable for machine learning, optimizing data quality and feature readiness?