On 13 Sep 2012, at 11:36pm, Igor Tandetnik <itandet...@mvps.org> wrote:
>> "statement-level read consistency. This guarantees that all the data >> returned by a single query comes from a single point in time—the time that >> the query began. Therefore, a query never sees dirty data or any of the >> changes made by transactions that commit during query execution. As query >> execution proceeds, only data committed before the query began is visible to >> the query. The query does not see changes committed after statement >> execution begins." > > But I can't help but wonder. Consider this scenario: > > begin; > update mytable set myfield=1; > commit; > > begin; > update mytable set myfield=2; > select myfield from mytable; > commit; > > Are you saying that in Oracle, the SELECT statement would observe myfield=1? > That seems to follow from the definition you quote, but I can't imagine how > such behavior could be useful. In SQLite, the SELECT statement would > certainly see myfield=2. Worse still, consider begin; update mytable set myfield=2; select myfield,anotherfield from mytable where myfield=1; commit; It's possible that you might get a row which didn't have myfield=1 at SELECT time ? Oh dear. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
