> I have a table like this: > > CREATE TABLE queue ( > key TEXT NOT NULL PRIMARY KEY UNIQUE, > status INTEGER > ); > CREATE INDEX IF NOT EXISTS keys ON queue (key);
Your index is redundant. There is already a unique index on key since it is a primary key. It should probably be: create unique index if not exists keys on queue(status, key); > And then I process it like this, N keys at a time: > > SELECT key FROM queue WHERE status=0 LIMIT N; > BEGIN TRANSACTION; > for key in keys: > UPDATE queue SET status=1 WHERE key=key; > END TRANSACTION; > > How can this SELECT and UPDATE be combined more efficiently? update queue set status=1 where key in (select key from queue where status=0 limit N); --- () ascii ribbon campaign against html e-mail /\ www.asciiribbon.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
