> My assumption is that if I opened this connection with this flag then this connection can be used only for reading, hence 'READ-ONLY connection'. Yes, the "main" database is opened r/o. Databases are attached r/o. Except of course "temp" which is r/w. Note that read-only does not mean immutable. Other connections can still write to the database. This means that all the "normal facilities" must be present to support this eventuality -- the prohibition against writing is merely logical.