When a user filters an Explore on a field type that supports suggestions, by default Looker will suggest possible values for the field (see Changing filter suggestions for information about how you can affect filter suggestions). To provide suggestions for a filter field, Looker executes a query on your database to retrieve a list of distinct values for the field. Looker typically generates these suggestions by executing a query such as the following on the filter field:
SELECT DISTINCT field_name FROM table
WHERE (field_name LIKE '%' OR field_name LIKE '% %')
GROUP BY 1 ORDER BY 1 LIMIT 1000
The suggestion parameter lets you hard-code the list of suggested values for a
dimension, filter field, or parameter that will appear when someone uses that field to filter a query.
If the field is in a large table, this query can be too slow or create too large a database load. By using suggestions you can hard-code a list of possible values instead and improve performance.
The suggestions parameter is also useful because it lets you specify a more limited list if you don't want certain values from a field to appear as suggestions.
Examples
Replace the default suggestions for the colors dimension with a hard-coded list:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-25 UTC."],[],[],null,["# suggestions (for fields)\n\n\u003e This page refers to the `suggestions` parameter that is part of a [dimension](/looker/docs/2512/reference/param-field-dimension), [filter field](/looker/docs/2512/reference/param-field-filter), or [parameter](/looker/docs/2512/reference/param-field-parameter).\n\u003e\n\u003e You can also use `suggestions` as part of a [view](/looker/docs/2512/reference/param-view-view), as described on the [`suggestions` (for views)](/looker/docs/2512/reference/param-view-suggestions) parameter documentation page.\n\nUsage\n-----\n\n```\nview: view_name {\n dimension: field_name {\n suggestions: [\"suggestion string\", \"suggestion string\", \"...\"]\n }\n}\n```\n\nDefinition\n----------\n\nWhen a user [filters an Explore](/looker/docs/2512/filtering-and-limiting) on a [field type that supports suggestions](/looker/docs/2512/changing-filter-suggestions#fields_that_support_suggestions), by default Looker will suggest possible values for the field (see [Changing filter suggestions](/looker/docs/2512/changing-filter-suggestions) for information about how you can affect filter suggestions). To provide suggestions for a filter field, Looker executes a query on your database to retrieve a list of distinct values for the field. Looker typically generates these suggestions by executing a query such as the following on the filter field: \n\n SELECT DISTINCT field_name FROM table\n WHERE (field_name LIKE '%' OR field_name LIKE '% %')\n GROUP BY 1 ORDER BY 1 LIMIT 1000\n\nThe `suggestion` parameter lets you hard-code the list of suggested values for a\n[dimension](/looker/docs/2512/reference/param-field-dimension), [filter field](/looker/docs/2512/reference/param-field-filter), or [parameter](/looker/docs/2512/reference/param-field-parameter) that will appear when someone uses that field to filter a query.\n| **Note:** Although Looker caches up to 1,000 results for this query, only the first 100 results appear to the user as filter suggestions.\n\nIf the field is in a large table, this query can be too slow or create too large a database load. By using `suggestions` you can hard-code a list of possible values instead and improve performance.\n\nThe `suggestions` parameter is also useful because it lets you specify a more limited list if you don't want certain values from a field to appear as suggestions.\n| **Caution:** The `label` values from the [`case`](/looker/docs/2512/reference/param-field-case) parameter will take precedence over suggestions presented to users from the `suggestions` parameter.\n\nExamples\n--------\n\nReplace the default suggestions for the `colors` dimension with a hard-coded list: \n\n dimension: colors {\n type: string\n sql: ${TABLE}.colors ;;\n suggestions: [\"red\", \"yellow\", \"blue\"]\n }"]]