Sometimes when you're building queries in Scuba, some data is less useful for you. For example, you might have back-end events with names that mirror front-end events, or device heartbeat data that you don't care about.
To simplify your query building, you can create a prefilter.
A prefilter is applied after retrieving data from disk, before any other calculations are performed. A prefilter can change your results. For example, say you have an actor property defined as sum(sales). Then say you have a prefilter that filters only to events that included use of a coupon. The sum(sales) actor property then shows only the sales that used a coupon.
When a prefilter is applied, Scuba still initially scans all events. As a result, a prefilter might not significantly improve performance on a long-running query.
Create a prefilter
To define a prefilter, do the following:
- In the Scuba UI ,navigate to Explore or any of the apps.
- Define a query.
- Below the query definition, but above the GO button, look for Pre-filtered to. Click all events to define the prefilter.
A prefilter must be an event property that uses only other event properties (including columns from a dataset).
About default prefilters and board filters
You might notice a prefilter on your query even before you add one. If so, this means that your admin has defined a default prefilter. A default prefilter runs on all queries, but not on boards or in the flow builder.
Remove a default prefilter by clicking its adjacent trash icon. To reapply a default prefilter, click Clear all in the query builder.
For more information about default prefilters, see Create a default prefilter in the Admin Guide.
A board can also supply a filter to queries that are pinned to it. To remove a board filter from your query, open the query in Explore. See Save variants of a board with board filters for more information.