Dimensions reference doc

Dimensions are the columns in your table. They are the "attributes" of your data. For example, user_id in your users table is a dimension.

Dimensions match 1:1 with columns in your dbt models.

Adding dimensions to your project

For a dimension to appear in Lightdash, you just need to declare it in your dbt model's YAML file.

version: 2

models:
  - name: my_model
    columns:
      - name: user_id # will be "User id" in LightDash
        description: 'Unique identifier for a user."

Column descriptions in your YAML file are automatically pulled into Lightdash and you can spot them if you hover over the dimension name 👀

screenshot-column-descriptions

Dimension types

Dimension types are automatically pulled from your tables schemas in Lightdash. We currently support these dimension types:

Dimension Types
string
number
timestamp
date
boolean

Dimension configuration

To customize the dimension, you can do it in your dbt model's YAML file.

version: 2

models:
  - name: sales_stats
    meta:
      joins:
        - join: web_sessions
          sql_on: ${web_sessions.date} = ${sales_stats.date}
    columns:
      - name: revenue_gbp_total_est
        description: "Total estimated revenue in GBP based on forecasting done by the finance team."
        meta:
          dimension:
            type: string
            label: 'Total revenue' # this is the label you'll see in Lightdash
            description: 'My custom description' # you can override the description you'll see in Lightdash here
            sql: "IF(${TABLE}.revenue_gbp_total_est = NULL, 0, ${registered_user_email})" # custom SQL applied to the column from dbt used to define the dimension
            hidden: false
            round: 2
            format: 'gbp'
            group_label: "Revenue"
      - name: forecast_date
        description: "Date of the forecasting."
        meta:
          dimension:
            type: date
            time_intervals: ['DAY', 'WEEK', 'MONTH', 'QUARTER'] # not required: the default time intervals for dates are `['DAY', 'WEEK', 'MONTH', 'YEAR']`
            urls:
              - label: "Open in forecasting tool"
                url: "https://finance.com/forceasts/weeks/${ value.raw }"
              - label: Open in Google Calendar
                url: 'https://calendar.google.com/calendar/u/0/r/day/${ value.formatted |split: "-" |join: "/"}'
            required_attributes:
              is_admin: "true"

All the properties you can customize:

Property	Required	Value	Description
label	No	string	Custom label. If you set this property, this is what you'll see in Lightdash instead of the dimension name.
type	No	Dimension type	The dimension type is automatically pulled from your table schemas in Lightdash but you can override the type using this property.
description	No	string	Description of the dimension in Lightdash. You can use this to override the description you have for the dimension in dbt.
sql	No	string	Custom SQL applied to the column used to define the dimension.
time_intervals	No	`'default'` or `OFF` or an array[] containing elements of date, numeric or string options	`'default'` (or not setting the `time_intervals` property) will be converted into `['DAY', 'WEEK', 'MONTH', 'YEAR']` for dates and `['RAW', 'DAY', 'WEEK', 'MONTH', 'YEAR']` for timestamps; if you want no time intervals set `'OFF'`.
hidden	No	boolean	If set to `true`, the dimension is hidden from Lightdash. By default, this is set to `false` if you don't include this property.
round	No	number	Rounds a number to a specified number of digits
format	No	string	This option will format the output value on the result table and CSV export. Currently supports one of the following: `['km', 'mi', 'usd', 'gbp', 'eur', 'percent', 'id']`
compact	No	string	This option will compact the number value (e.g. 1,500 to 1.50K). Currently supports one of the following: `['thousands', 'millions', 'billions', 'trillions']`
group_label	No	string	If you set this property, the dimension will be grouped in the sidebar with other dimensions with the same group label.
urls	No	Array of { url, label }	Adding urls to a dimension allows your users to click dimension values in the UI and take actions, like opening an external tool with a url, or open at a website. You can use liquid templates to customise the link based on the value of the dimension.
required_attributes	No	Object with { user_attribute, value }	Adding urls to a dimension allows your users to click dimension values in the UI and take actions, like opening an external tool with a url, or open at a website. You can use liquid templates to customise the link based on the value of the dimension.

Compact values

You can compact values in your YAML. For example, if I wanted all of my revenue values to be shown in thousands (e.g. 1,500 appears as 1.50K), then I would write something like this in my .yml:

    version: 2
    models:
    - name: sales
      columns:
        - name: revenue
          meta:
            dimension:
                compact: thousands # You can also use 'K'

Value	Alias	Example output
thousands	"K" and "thousand"	1K
millions	"M" and "million"	1M
billions	"B" and "billion"	1B
trillions	"T" and "trillion"	1T

Time intervals

Lightdash automatically adds intervals for dimensions that are timestamps or dates, so you don't have to!

For example, here we have the timestamp dimension created defined in our dbt project:

      - name: created
        description: 'Timestamp when the user was created.'

Lightdash breaks this out into the default intervals automatically. So, this is how created appears in our Lightdash project:

screenshot-default-intervals

By default, the time intervals we use are:

Date: ['DAY', 'WEEK', 'MONTH', 'YEAR']

Timestamp: ['RAW', 'DAY', 'WEEK', 'MONTH', 'YEAR']

To turn off time intervals for a dimension, set `time_intervals: OFF`

If you want to turn off time intervals for a dimension, you can simply set the time_intervals property to OFF.

In this example, created would now appear as a single, timestamp dimension without a drop-down list of time intervals in Lightdash:

      - name: created
        description: 'Timestamp when the user was created.'
        meta:
          dimension:
            time_intervals: OFF

screenshot-intervals-off

Date options

Option	Description	Type	Displayed value	Notes
RAW	Original value	Date / DateTime	2019-01-01 / 2019-01-01, 09:30:30:300 UTC
YEAR	Date truncated to the nearest year	Date	2019
QUARTER	Date truncated to the nearest quarter	Date	2019-Q1
MONTH	Date truncated to the nearest month	Date	2019-01-01
WEEK	Date truncated to the nearest week	Date	2019-01-01	The start of the week depends on your warehouse configuration
DAY	Date truncated to the nearest day	Date	2019-01-01
HOUR	Datetime truncated to the nearest hour	DateTime	2019-01-01, 09 UTC
MINUTE	Datetime truncated to the nearest minute	DateTime	2019-01-01, 09:30 UTC
SECOND	Datetime truncated to the nearest second	DateTime	2019-01-01, 09:30:30 UTC
MILLISECOND	Datetime truncated to the nearest millisecond	DateTime	2019-01-01, 09:30:30:300 UTC

Numeric options

Option	Description	Type	Displayed value	Notes
DAY_OF_WEEK_INDEX	Index of the day of the week	Number	0	The value range and start of the week depends on your warehouse configuration
DAY_OF_MONTH_NUM	Day of the month	Number	21
DAY_OF_YEAR_NUM	Day of the year	Number	127
MONTH_NUM	Month number	Number	7
QUARTER_NUM	Quarter number	Number	3
YEAR_NUM	Year number	Number	2019

String options

Option	Description	Type	Displayed value
DAY_OF_WEEK_NAME	Day of the week	String	Monday
MONTH_NAME	Month name	String	March
QUARTER_NAME	Quarter name	String	Q3

Format

You can use the format parameter to have your dimensions show in a particular format in Lightdash. These are the options:

Option	Description	Raw value	Displayed value
km	Adds the suffix `km` to your value	10	10 km
mi	Adds the suffix `mile` to your value	10	10 mi
usd	Adds the `$` symbol to your number value	10	$10.00
gbp	Adds the `£` symbol to your number value	10	£10.00
eur	Adds the `€` symbol to your number value	10	€10.00
percent	Adds the `%` symbol and multiplies your value by 100	0.1	%10
id	Removes commas and spaces from number or string types so that they appear like IDs.	12,389,572	12389572

URLs

Lightdash users can interact with dimension values by clicking on them. By adding custom urls you can configure the actions available to your users. Like linking to external tools, or taking actions in other tools.

In the example below, users can click on a company name and open a corresponding record in their CRM or search for the company in google or open that company's Slack channel.

columns:
  - name: company_name
    label: Registered trading name of the company
    meta:
      dimension:
        urls:
          - label: Search for company in Google
            url: "https://google.com/search?${ value.formatted | url_encode }"
          - label: Open in CRM
            url: "https://mycrm.com/companies/${ row.company.company_id.raw | url_encode }"

The ${ value.formatted } will be replaced with the value of the company name in the Lightdash UI at query run time. The ${ row.company.company_id.raw } will be replaced with the value of the company id in the Lightdash UI at query run time. The action will be disabled if the column "company_id" from table "company" is not part of the query.

You can reference values from other columns in your URLs

You can reference another dimension from your table in your URL. For these URLs to work, the other column you've referenced needs to be included in your results table. For example, say I’ve added a URL to company_name and it uses the field customer_id:

columns:
  - name: company_name
    label: Registered trading name of the company
    meta:
      dimension:
        urls:
          - label: "Open company"
            url: "https://example.com/company/${row.customers.customer_id.raw | url_encode }"

This URL will only work if I have customer_id included in my results table.

Required attributes

Lightdash can use user attributes to limit some dimensions to some users.

In the example below, only users with is_admin attribute true can use the salary dimension on user table

columns: 
  - name: 
    description: User name
  - salary: 
    description: User salary 
    meta: 
      dimension: 
        required_attributes: 
          is_admin: true 

Users without access to this dimension will not see it on the explore page.

If a user without access to this dimension runs a query that contains this dimension, they will get a Forbidden error.

Current limitations

Lightdash dimensions and custom metrics are protected by this feature, however, it is possible to write custom SQL to bypass this filter, for example:

Developers and admins running SQL queries on SQL runner.
Custom SQL or subqueries on table calculations

info

Scheduler deliveries will run against the user who created the scheduled delivery, be careful when sharing required attributes with other users.

Liquid Templating

Use templates to configure the url values depending on the query, this allows your urls to depend on the results of queries.

Available liquid tags

Tag	Description
`${ value.formatted }`	The exact value of the dimension as seen in the Lightdash UI. For example "$1,427.20"
`${ value.raw }`	The raw value of the dimension returned from the underlying SQL query. For example "1427.2 "
`${ row.table_name.column_name.formatted }`	The exact value of the column as seen in the Lightdash UI. For example "$1,427.20"
`${ row.table_name.column_name.raw }`	The raw value of the dimension returned from the underlying SQL query. For example "1427.2 "

Available liquid filters

Filters can be used to make small transformations of your values:

Filter	Description	Example usage
url_encode	Encode a string as url safe, for example it replaces spaces with `%20`	`${value.formatted \
downcase	Convert string to all lowercase	`${value.formatted \
append	Append a string to another	`${value.formatted \

There are many more filters available in the Liquid documentation.

Using special characters or capital letters in your column names

If you use special characters on your column names, you might get errors when using those columns on explore. For example, having a column named Status with capital S on a table named orders in postgres throws the following error:

column orders.status does not exist

To fix this, we can add the quoted column to our sql meta tag on dimensions

- name: status
  meta:
    dimension:
      type: string
      sql: '"orders"."Status"' # you can also use '${TABLE}."Status"'

This will quote the Status columns on the SQL query

SELECT
  "orders".order_id AS "orders_order_id",
  "orders"."Status" AS "orders_status"
FROM "postgres"."jaffle"."orders" AS "orders"

Dimensions reference doc

Adding dimensions to your project​

Dimension types​

Dimension configuration​

Compact values​

Time intervals​

By default, the time intervals we use are:​

To turn off time intervals for a dimension, set time_intervals: OFF​

Date options​

Numeric options​

String options​

Format​

URLs​

You can reference values from other columns in your URLs​

Required attributes​

Current limitations​

Liquid Templating​

Using special characters or capital letters in your column names​