Last Updated: December 17, 2024

Note: Google Data Studio is now known as Looker Studio.

A data source schema is made up of a set of fields called the data source schema fields:

A connector is used to pull these fields from a data source.

Only the fields provided by the connector are the ones available to use in your schema and reports.

There are two broad categories of data source fields in Looker Studio: 

• Regular fields
• Calculated fields

Regular fields

It is a field that doesn’t perform an action(s) on another field(s) in your data source schema or chart.  

Calculated fields

It is a field that performs certain action(s) on another field(s) in your data source schema or chart via a formula. These actions could be:

• Arithmetic and math operations
• Manipulating text, date and geographic information
• Using branching logic to evaluate data

Through calculated fields, you can create new metrics and dimensions.

Regular fields can be further categorized into:

• Data Source Schema specific fields
• Chart Specific (or chart level) fields

Data Source Schema specific field

It refers to the regular field of a data source schema. The data source schema field is available in any report that uses that data source schema.

Chart Specific (or chart level) field

It refers to the regular field of a specific chart in a report. The chart specific field is not available to other charts of the same or other Looker studio reports.

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Data source schema specific fields can be further categorized into:

• Data source schema specific dimensions
• Data source schema specific metrics

Data source schema specific dimension

It refers to the regular dimension of a data source schema. 

The regular dimension is the field that is used to describe or categorize your data. In the context of Google Analytics, dimension is one of the attributes of your website visitors. 

The data source schema specific dimension is available in any report that uses that data source schema.

Data source schema specific metric

It refers to the regular metric of a data source schema. 

The regular metric is the field that is used to measure one of the characteristics of a dimension. In the context of Google Analytics, metrics is a numeric field which is used to measure one of the characteristics of a GA dimension. 

The data source schema specific metric is available in any report that uses that data source schema.

Chart specific (or chart level) fields can be further categorized into:

• Chart specific (or chart level) dimensions
• Chart specific (or chart level) metrics

Chart specific (or chart level) dimension

It refers to the regular dimension of a specific chart in a report. 

The chart specific dimension is not available to the charts of the same or other Looker Studio reports.

Chart specific (or chart level) metric

It refers to the regular metric of a specific chart in a report. 

The chart specific metric is not available to the charts of the same or other Looker Studio reports.

Following is the visual summary:

Calculated fields can be further categorized into:

• Data Source Schema specific calculated fields
• Chart Specific (or chart level) calculated fields

Data Source schema specific calculated field

It is the calculated field created in a data source schema. 

When you create a calculated field in a data source schema, the calculated field is available in any report that uses that data source schema. 

A Looker studio report which uses multiple data source schemas is based on multiple data sources: 

Note: You can’t use a data source specific calculated field with blended data (more about blended data later).

Chart specific (or chart level) calculated field

It is the calculated field created in a specific chart in a report. 

When you create a calculated field in a chart, the calculated field is available only in the chart in which you create it. 

However, you can use a chart specific calculated field with blended data.

Note: When using a chart specific calculated field, you can not reference other chart-specific calculated fields in your formula, even if those fields are defined in the same chart. If you want to reference other calculated fields, use a data source schema specific calculated field.

Data source schema specific calculated fields can be further categorized into:

• Data source schema specific calculated dimensions
• Data source schema specific calculated metrics

Data source schema specific calculated dimension

It is the dimension that performs certain action(s) on another field(s) in your data source schema via a formula. 

When you create a calculated dimension in a data source schema, the calculated dimension is available in any report that uses that data source schema. 

Note: All calculated dimensions appear in the data source schema with an ‘fx’ symbol.

Data source schema specific calculated metric

It is the metric that performs certain action(s) on another field(s) in your data source schema via a formula. 

When you create a calculated metric in a data source schema, the calculated metric is available in any report that uses that data source schema. 

Note: All calculated metrics appear in the data source schema with an ‘fx’ symbol.

Chart specific calculated fields can be further categorized into:

• Chart specific calculated dimensions
• Chart specific calculated metrics

Chart specific calculated dimension

It is the dimension that performs certain action(s) on another field(s) in your chart via a formula. 

When you create a calculated dimension in a chart, the dimension is available only in the chart in which you create it. 

However, you can use a chart specific calculated dimension with blended data.

Chart specific calculated metric

It is the metric that performs certain action(s) on another field(s) in your chart via a formula. 

When you create a calculated metric in a chart, the metric is available only in the chart in which you create it. 

However, you can use a chart specific calculated metric with blended data.

Following is the visual summary:

The parameter field

While editing a data source schema, you get the option to add one or more parameter fields:

A parameter is a data source schema field whose value is supplied by a report user. It is used in calculated fields and report components just like a dimension or a metric.

Through parameters, you can pass user-supplied data to calculated fields and connectors. So if you want your report to display results based on user input then you use the parameter field.

You will find parameters at the bottom of the list of the available fields in your data source schema or report editor:

Note: Parameters appear as a purple field.

To learn more about parameters in Looker studio, read this article: How to create and use parameters in Looker Studio.

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Introduction to fields data types

The data type of a data source field determines the kind of data to expect (in the specified data set) when processing the field. 

For example, when the data type of a field is ‘Number’ it tells Looker Studio to expect a number when processing the field.

When the data type of a field is ‘Currency (US – Dollars) it tells Looker Studio to expect currency data in US dollars when processing the field.

Similarly, when the data type of a field is ‘Text’ it tells Looker Studio to expect text data when processing the field.

The data type determines which operations are allowed and not allowed on a data source field.

For example, you can’t apply an arithmetic function to a ‘Text’ field or use a ‘Number’ field as the date range dimension in a report.

If you want to change the data type of a field then just click on the drop-down menu next to a data type.

Note: Changing the field type can have a considerable impact on how you see your data in reports.

Looker Studio supports the following data types:

1. Numeric
2. Text
3. Date and Time
4. Boolean
5. Geo
6. Currency
7. URL
8. Image
9. Image link

To learn more about the various data types in Google Looker studio, read this article: Guide to Data Types in Looker Studio