Data processing in REDS (Walmart DSP)
There is a vast amount of data included in Raw Event Data Stream (REDS) feeds, and every partner has the ability to modify which columns are included from each stream. To gather the schema specific to your REDS feed efficiently, the Walmart DSP offers a suite of REDS API endpoints that allow retrieving the definitions of all your REDS feeds and the enumeration maps for all impression-feed facets.
The following table highlights the contents of all REDS data streams. To view examples of stream data and events, download the REDS sample data file.
| Data Streams | Description |
|---|---|
| Impressions | Information about won impression events. |
| Clicks | Information about click events. |
| Video events | Post-impression event information relating to viewability, audio, and video metrics. |
For a complete list, see REDS feeds.
Impressions stream
All won impression events are tracked in the Impressions stream. It records the users (cookies or device IDs) to whom an impression was served, along with their associated metadata.
Processing tips
The following section describes how data is processed in an impression stream.
- The impression ID is an identifier of an impression event in a partner account, but it is not considered to be the 'unique identifier' for every event.
- Due to how we process our logs, some data that is captured near the beginning of an hour may be logged in the previous hour's folder. For example, an impression event that occurred at 14:01:03 UTC may be filed in the folder for hour 13 instead of hour 14.
Clicks stream
All recorded click events are tracked in the Clicks stream. It records the users (their cookies or device IDs) that clicked a creative, along with their associated metadata.
Processing tips
The following section describes how to process data in an clicks stream by using the impression ID.
- To join Clicks to Impressions, use the impression ID. Since there is a direct link between clicks and impressions, you can also join on the bid request ID or display impression ID.
- Though very rare, there can be instances in which a click event cannot be attributed to an Impressions event, but can be tracked back to a bid. This can happen when the feedback call gets modified before we have an opportunity to record it. This is just an anomaly of the Internet. Certain browsers with an ad blocker can change the query parameters on our feedback pixel, disabling our ability to parse and record impressions; however, the click generated from the impression is perfectly valid.
Video events stream
The Video events stream is a post-impression event feed with data pertaining to viewability, video events, and video-quartile metrics.
NOTE: This event feed also contains audio event data.
Processing tips
The following section describes how to process data in an video event stream by using the impression ID.
- Impression IDs included within the Video events feed can be joined to an impression ID within the Impressions feed.
- Every impression may not have a post-impression event that is recorded in this feed. Multiple records are expected for a given impression ID, as each record will define the tracked activity. For example, you will receive one record if the video was in view, and a separate record if the video started playing, etc.
- We track viewability on a sample of your total impressions (by default, 13% of impressions are appended with MOAT viewability pixels). If you would like the sample rate increased, please speak with your Account Manager.