What a single row in a fact table stands for at its most detailed level, defined by its dimension keys and attributes, such as one row for each order line on each day.
Also called granularity.
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Terms in this definition
- Fact table
Stores the numbers captured when business events happen, like what each sale brought in; an analytical model rolls these up into measures and slices them by dimensions.
Related terms
- Aggregate table
A summarised copy of a fact table at a coarser grain or with fewer dimensions (daily store sales, for instance) that makes frequent queries faster. Power BI semantic models can achieve the same result through user-defined aggregations.
- Data lineage
Unity Catalog tracks, without any set-up and at column granularity, where data comes from and where it goes across tables, notebooks, pipelines, jobs and dashboards. You can explore the graph in Catalog Explorer or query it through system tables.
- Degenerate dimension
Something like an order number that describes the data but has the same grain as the fact table, so it lives in the fact table instead of a dimension table of its own; a Power Query table or a view can expose it.
- Dimensionality
Which dimension keys a fact table carries determines its dimensionality. Granularity is a separate idea: it depends on the key values themselves.
- Sort by column
Lets one column, such as Month Name, be ordered by another at the same grain, such as Month Number, using the Column tools tab. Every value in the sorted column must correspond to exactly one sort-by value.