Translations:Help:CirrusSearch/433/en

Regex scan all the textual characters in a given list of pages; they don't have a word index to speed things up, and the process is interrupted if it must run more than twenty seconds. Regex run last, so to limit needless character-level scanning, you advance it a list of pages (a search domain) selected by an indexed search added to the query as a "clause", and you do this to every single regex query.