One possibility: Does ATTACH DATABASE count as a schema change?
From: Vince Scafaria Sent: Monday, February 29, 2016 10:31 PM To: 'sqlite-users at mailinglists.sqlite.org' <sqlite-users at mailinglists.sqlite.org> Subject: Database is locked (wal) - purely from read-only connections/queries Richard, I can confirm that having a writable connection open first, prior to trying any reads, does avoid the "database is locked" error. However, I still do get "SQLite error (17): statement aborts" errors. What are the rules I must follow to avoid getting these SQLITE_SCHEMA errors? I am not running any SQL that I would generally consider to be altering the schema. I'm simply doing multiple concurrent reads on read-only connections and running INSERT/UPDATE (not CREATE/DROP) statements on the writable connection. Thank you. Vince Scafaria
