Thread:Extension talk:DynamicPageList (Wikimedia)/Performance concerns regarding the Intersection extension/reply

Yes this is still the case.

The performance concerns would be difficult to address (or at least beyond my ability) unless we store category membership information in a different type of data structure (aka something other than the db).

I don't think there were any discussions about this. Its fairly self-obvious if you look at the code. (People like to point at it being enabled at en.wikitonary for how it can't be that bad, but I think the fact its enabled there is more a historical accident than anything else [that is of course just my opinion]. One could easily make queries there that would take longer to complete then the timeout for rendering a page.