Data Blending

Data blending combines data from two or more separate data sources into a single view, using a common field to link them together.

How Blending Works

Tableau treats one data source as the primary and the other as secondary. When a field from the secondary source is added to a view, Tableau aggregates its values and matches them to the primary source using shared linking fields.

Setting Up a Blend

Connect to the first data source (primary)
Connect to the second data source (secondary)
Drag fields from both onto the same worksheet
Tableau automatically detects and links matching field names

Blending vs Joining

A join combines data at the row level before aggregation, within the same connection, while blending combines already-aggregated results from two separate data sources at the visualization level.

Common Use Case

Blending is useful when combining data that lives in genuinely different systems - for example, sales data from a database and target figures from a spreadsheet - where a full join isn't practical.