Can you explain the concept of ELT in the context of Dart and how it differs from ETL?

The ELT (Extract, Load, Transform) concept in the context of Dart and Flutter is typically used when working with data and differs from the traditional ETL (Extract, Transform, Load) order of operations.

• ETL: Data is first extracted (Extract), then transformed (Transform) into the required format or structure, and only after that loaded (Load) into the target system.

• ELT: Data is first extracted (Extract), then immediately loaded (Load) into a storage or database, and the transformation (Transform) occurs within the target system.

In the context of Dart/Flutter, ELT can mean that the application receives data (for example, from an API), immediately saves it locally (for example, in an SQLite or Hive database), and then performs data transformations and processing within the application for display or further use.

This approach allows separating the loading and processing stages, increasing performance and flexibility, especially when working with large volumes of data or offline mode.

Example:

// Extract & Load
final rawData = await fetchDataFromApi();
await localDatabase.save(rawData);

// Transform
final processedData = await localDatabase.queryProcessedData();

Thus, ELT in Dart/Flutter is an approach where data is first saved, then processed, unlike the traditional ETL where processing occurs before loading.