Yes, I also wrote some virtual tables e.g. to read a directory listing or a list of lines from all files which are selected by another SQL statement or simply to use DBase/FoxPro files from within SQLite (long time ago now and not used anymore since about 2010); but this was long before the value enabled virtual tables became invented. I may have to step into this subject myself once more to see if and how our wishes for parameterized functionality can be accomplished with that capabilities. Unfortunately I am very busy and short in time. But thanks for this good hint.