We are using multiple processes accessing the same on-disk db with almost exclusively virtual tables.
Once the tables have been declared (CREATE VIRTUAL TABLE...), all other connections need only to load the modules. The xConnect method gets called on first access. -----Urspr?ngliche Nachricht----- Von: Dominique Devienne [mailto:ddevienne at gmail.com] Gesendet: Dienstag, 06. Oktober 2015 15:51 An: sqlite-users at mailinglists.sqlite.org Betreff: [sqlite] Multiple connections to in-memory DB and virtual tables We use (for years now) an in-memory DB with both tables and virtual tables in our app. We recently started experimenting with multiple connections to the same in-memory DB, thanks to URI filenames and shared cache, to perform queries in parallel. This seems to work well with regular tables, and we get close to a 3x speedup using 4-5 threads on some use cases (running many queries). But now we're trying to configure virtual tables and multiple connections to that unique in-memory DB, and we're having some trouble. We're not sure yet it's not related to our code, which so far assumed a single connection was in use accessing the vtables, but I'd like to get a reality check for that use case from experts. On the first connection, we declare the virtual module and its virtual tables. This also adds the vtables to sqlite_master. But then on additional connections to that same in-memory DB, we also need to declare a vmodule and vtables, right? Yet it's already in sqlite_master, and it fails on the "create virtual table" statement. Is this use case supported by SQLite? Has any one tried this successfully? Any chance this might work in the near future? Thanks for any input on this. --DD PS: assume read-only use cases for now, and no concurrent writes during these // queries. _______________________________________________ sqlite-users mailing list sqlite-users at mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users ___________________________________________ Gunter Hick Software Engineer Scientific Games International GmbH FN 157284 a, HG Wien Klitschgasse 2-4, A-1130 Vienna, Austria Tel: +43 1 80100 0 E-Mail: hick at scigames.at This communication (including any attachments) is intended for the use of the intended recipient(s) only and may contain information that is confidential, privileged or legally protected. Any unauthorized use or dissemination of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by return e-mail message and delete all copies of the original communication. Thank you for your cooperation.
