Summary of ETL - Extract Transform Load | Summary of all the key concepts in building ETL Pipeline
ETL (Extract Transform Load) is essential for building a data warehouse.
- The extract phase involves getting data from various sources in different formats.
- real-time streaming, batch processing, and flat files are common methods for extraction.
- Complex logic is avoided in the extraction phase, with basic transformations like date calculations.
- Data format consistency is crucial to ensure uniform representation of data from multiple sources.
- data quality rules can be applied during extraction to ensure data integrity.
- staging tables are used for extraction and are typically truncated and loaded without running business queries.
- Load strategies include full and delta loads, with historical loads done initially.
- The transform phase involves applying data transformations to make raw data meaningful.
- Common transformation steps include mapping, data enrichment, joins, filters, removing duplicates, and aggregation.
- dimension tables require primary and foreign keys, attributes, load strategies, and granularity definitions.
- Fact tables contain measures and have primary and foreign keys to relate to dimension tables.
- The EDW (Enterprise data warehouse) stores processed data for business decisions, while data marts are subject-specific areas for analysis.
- The load phase involves loading data into dimension tables, fact tables, EDW, and data marts.
- The video serves as a comprehensive guide for both beginners and experienced professionals in ETL development.
Speakers
- Nitin (host)
Notable Quotes
— 10:59 — « in transform phase whatever data you have ingested in your staging tables you will apply different data transformations or different data mapping rules on it to make it more meaningful. »
— 16:14 — « and in transform phase you can enrich the data. »
— 17:46 — « when youre loading a dimension table these are the key points you should consider: dimension table must also have a functional identifier or a natural key. »
— 20:52 — « so there is a foreign key relationship between primary key and foreign key. »
— 21:34 — « dimension tables are always loaded first and the fact table source the primary key of dimension table into it as a reference them as a foreign key. »
Category
Educational