Parameters

As explored in the article, Understanding the GA4 BigQuery Export Schema and Structure, the GA4 BigQuery export schema has a very challenging structure, with nested and repeated fields being particularly complex

One of the major benefits of using Decode GA4 is that it automatically flattens event_params, user_properties, and optionally and item_params, which are represented by complex nested and repeated columns in the raw export.

It also detects precisely which data types are observed and extracts the data into the appropriate data type based on this observation.

Event Parameters

There are sets of standard event parameters to be expected, as outlined in the following Google Analytics documentation.

An example of the actual event_parameter values in a standard, live web property are shown below, along with observation frequency, first/last dates, observed data types and the BigQuery data type for the event_parameter struct sub-columns.

These parameter statistics are available to inspect post-installation.

Values are accessed using the dot notation (e.g. event_parameter.engagement_time_msec).

As in a standard installation, in our example data there are no default user properties or item parameters, and none observed.