We have a list of items with 12,000 items (let's say "Tools") or so. We are trying to filter for a lookup value, as follows:
ClearCollect(ToolsCollection,Filter(Tools, Toolbox.Id=12345))
ClearCollect
The ClearCollect function deletes all the records from a collection and then adds a different set of records to the same collection. With a single function, ClearCollect offers the combination of Clear and then Collect. ClearCollect returns the modified collection as a table. ClearCollect can only be used in a behavior formula. Ref: https://powerapps.microsoft.com/el-gr/blog/powerapps-data-row-limit-for-non-delegable-queries/
However, it is not returning any items (for some Tools anyway). NB I can create a filtered list in SharePoint that is filtered to "Toolbox (indexed)".