A contract-specific limit exists, that restricts the number of trackable expressions per dimension (e.g. page, event, ad media, ...).
For example: How many different pages can be tracked in total?
Therefore, Mapp provides the possibility to different group expressions. For example, All pages, that have been accessed only once.
The expressions, that were grouped like this, are depicted as "webtrekk_aggregated". In our example, all Page Impressions of the grouped pages would be assigned to the new page "webtrekk_aggregated".
Please refer to the Support for activating data cleansing.
What does webtrekk_fallback mean?
How does an automatic limit cleanup work?