SELECT ix FROM qpvtab WHERE vn='sqlite3_vtab_distinct';
SELECT DISTINCT ix FROM qpvtab WHERE vn='sqlite3_vtab_distinct';
SELECT distinct vn, ix FROM qpvtab(3)
WHERE +vn IN ('sqlite3_vtab_distinct','nOrderBy');
SELECT vn, ix FROM qpvtab
GROUP BY vn
HAVING vn='sqlite3_vtab_distinct';