2017-07-25, 09:06
(2017-07-25, 08:32)jingai Wrote: Do you think it'd be possible to set derived_merge=off only for queries that DELETE from a table used in a subquery rather than setting it unconditionally for 5.7.6+?
I'm sure it would be possible to analyze the query in the MySQL database wrapper in order to detect DELETE queries and apply the setting before executing such a query (then unset it afterwards) but... that's just a bigger hack than the one we have already. Obviously for a connection that doesn't need the setting (pre 5.7.6) none of this would be required so any "analyzing" could be skipped entirely. Can't be done higher up because SQLite doesn't care about this. Then everything would need to be thoroughly re-tested.