I want the sql to be executed on a copy of Moodle database, not the Moodle database. I went to Admin -> Plugins -> Blocks -> Configurable Report settings, I filled in the "DB Host", "DB Name", "DB Username", "DB Password" and saved them. But the sql of Configurable reports still ran on the Moodle DB. Then I configurable the database settings of Configurable reports using some wrong information, but the configurable reports still ran on the Moodle database (it should report that the database connection fails.). No matter what I input for the database settings for Configurable reports, it always accesses the Moodle database to execute the sql.