view: view_name {
  dimension: field_name {
    allow_fill: yes 
Possible Field Types
Dimension, Dimension Group

Default Value

A Boolean (yes or no)


Some datasets have values, such as dates, that follow a predictable pattern. A user might pull data by a time frame and find that some dates, weeks, months, or other date types don't have any corresponding value. By default, the data table and the visualization will display the dates that the query returns and skip any missing dates.

For these cases, Looker's dimension fill option lets the user fill in missing dates and values in the data table and in the axis of the query's visualization. This option is found in the dimension's gear menu in the Data section of an Explore.

The allow_fill parameter for a dimension is used to enable or disable the option to fill in the missing values in the data table and in the axis of the visualization. By default, if the dimension type supports filling in missing values, the option is shown in the dimension's gear menu. To disable the option to fill in missing values for a dimension, set allow_fill to no.

The allow_fill option is available for dimension groups and dimensions that have a fixed number of values, such as yes/no and tiered values, as well as date types such as day_of_week or hour_of_day.

You can also use the case or tier parameter to apply the allow_fill option to any dimension option that is based on a list of values. Missing values are filled in automatically for queries that run with a single dimension and/or a single pivot, as long as the user has not applied filters to any measures.

Dimension fill can be applied to multiple dimensions at once in a query — including pivoted dimensions — however, Looker may automatically disable dimension fill to optimize query performance if it detects that too many fields will be generated with filled values.


Prevent a user from being able to fill in missing values for the Created Date dimension:

dimension: created_date {
  type: date
  sql: ${TABLE}.created_date ;;
  allow_fill: no

Things to consider

There are a few other cases when the user will not be able to dimension fill:

  • When dimensions make use of the order_by_field parameter.

  • When dimensions have a filter applied to them and also have a fixed number of values, such as yes/no, days of the week, days of the month, and so on. Filtering against these field types eliminates the fixed number of values that Looker needs to accurately fill in missing values.

  • When the user is drilling into a pivoted dimension.

  • When Looker detects that too many rows or columns will be generated with filled values and automatically disables dimension fill to optimize query performance.