Collecting and updating of User ID values for previous sessions

Benefits of using User ID

User ID helps you collect user behavior data across multiple devices and sessions, using the unique user ID from your CRM. In other words, it lets you connect data about actions of a single user on different devices, thus allowing for a deeper analysis of each user interaction with your website.

Collect User ID data into tables with hits data

In the tables with hits data User IDs are collected into userId field.
The field takes values of &uid parameter of queries that send your Google Analytics data.

Collect User ID data into tables with sessions data

In the tables with sessions data User IDs are collected into user.Id field.

To collect the data, please set values of which custom dimension you want to collect on the «Settings» tab of your pipeline:

If don't have required custom dimension but collect data in tables with hits data, it will be saved to tables with sessions data too.

Data update

Value of user.Id filed updates for the sessions every day for period of the last 30 days.


  • 1st session — clientId:CID — user.Id:NULL
  • 2nd session — clientId:CID — user.Id:UID

In this case all user.Id:NULL with clientId:CID get the UID value.

Another example:

  • 1st session — clientId:CID — user.Id:UID1
  • 2nd session — clientId:CID — user.Id:UID2

A user had user.Id:UID1 that later changed to UID2 value. In this case value UID2 isn't assigned to the session where user.Id value is UID1.

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