ETL Data Transformations

Start with expressions and filters

Begin with Expression Transformation to explore calculations within a single row. The map covers conditional tests and non-aggregate calculations, as well as where an expression transformation can be created. Use its branches to organize the points you want to remember.

Next, open Filter Trans. It shows how a filter condition lets matching rows pass and drops rows that do not meet the condition. Compare it with the other filter map, which also covers true, false and null conditions.

Follow the join maps

The join maps offer different starting points for studying source data. One describes matching columns between sources and introduces master and detail branches. Another covers joining related sources or data from the same source, including where the master and detail pipelines go.

Once those ideas are familiar, look at the map on the transaction scope property. It distinguishes preserving transaction boundaries from dropping them. Move between the maps to connect the master and detail branches with the transaction scope choices.

Compare other transformations

The union map describes merging data from multiple pipelines or branches into one pipeline without removing duplicates. The aggregation map covers calculations on groups, aggregate expressions and conditional clauses. Compare these with the expression map to distinguish group calculations from calculations within a single row.

Use the maps together

There are no quizzes listed on this page. With a free account, you can make your own quiz and use it alongside the maps, returning to a branch when you want to check an explanation. These transformation resources are part of a wider unit in Databases and data science. Choose a map and follow its branches as a starting point.