--- title: "KEEP modifier" slug: "keep-modifier" updated: 2025-12-23T10:25:23Z published: 2025-12-23T10:25:23Z --- > ## Documentation Index > Fetch the complete documentation index at: https://kb.pigment.com/llms.txt > Use this file to discover all available pages before exploring further. # KEEP modifier ## Description Retains the listed Dimensions on a Block and removes all others. ## Syntax `source_block [KEEP [aggregator] [ON RANK(<dimension1>)]: dimension2[, dimension3]]` - `source_block` The Metric whose Dimensions you want to keep. - `aggregator` The aggregation method applied to the removed Dimensions (e.g. `SUM`, `AVG`, `FIRST`, `FIRSTNONBLANK`). If omitted, the default is `SUM`. - `ON RANK` () Required when KEEP retains more than one Dimension and the aggregation is `FIRST` or `FIRSTNONBLANK`. Omitting `ON RANK` in this situation produces an error. See **Examples**below. - `dimension1` The Dimension you want to retain. - `dimension2` Any additional Dimensions to retain, separated by a comma. The default aggregator, if omitted, is `SUM` for objects of the Number data type. Other aggregators are described in the article [Aggregation data in formulas](/v1/docs/aggregate-data-in-formulas#aggregation-methods). ## Return type `same as source object` ## Examples `Revenue` is a Metric of the Number data type, with the following Dimensions: `Country`, `Product`, and `Month`. | Case | Results | | --- | --- | | `Revenue[KEEP SUM: Country]` | Returns the Revenue by Country where all other Dimensions were aggregated using sum. | | `Revenue[KEEP AVG: Month]` | Returns the Revenue by Month where all other Dimensions were aggregated using average. | | `Revenue[KEEP FIRSTNONBLANK ON RANK(Product): Country, Month]` | Returns the Revenue by Product, Country and Month, taking the first non-blank value of the Product Dimension. The ON operator is used with the [RANK function](/v1/docs/rank-function) to define which Dimension provides the first non-blank value. | **See also**: [REMOVE](/v1/docs/remove-modifier)