This is a common question if the data you’re collecting has evolved over time. For example, if you used to track the event
Signup but now track
Signed Up, you’d probably like to merge those two tables to make querying simple and understandable.
Segment does not have a way to update the event data in the context of your warehouse to retroactively merge the tables created from changed events. Instead, you can create a “materialized” view of the unioned events. This is supported in Redshift, Postgres, Snowflake, and others, but may not be available in all warehouses.
Protocols customers can also use Transformations to change events at the source, which applies to all cloud-mode destinations (destinations that receive data from the Segment servers) including your data warehouse. Protocols Transformations offer an excellent way to quickly resolve implementation mistakes and help transition events to a Segment spec.
Note: Transformations are currently limited to event, property and trait name changes, and do not apply to historical data.