Implement bulk_create auto-incrementing pk assignment on MySQL when possible

[Simon Charette]

​From this article it seems that it might be possible to implement AutoField (and friends) assignment on MySQL for bulk_create by using a range of (last_insert_id(), last_insert_id() + affected_rows) .

​The criteria are the following

Use simple-inserts (e.g. no subquery or insert from select) and don't mix objects with primary keys and ones without.

bulk_create doesn't rely on subqueries and ​it already partitions between objects with and without a primary key.

Don't use innodb_autoinc_lock_mode=2 (interleaved) with binlog_format=STATEMENT

This is detectable by issuing introspection just like we do with other connection.features.

The default on MySQL 5.7 was (innodb_autoinc_lock_mode=1, binlog_format=STATEMENT) and is (innodb_autoinc_lock_mode=2, binlog_format=ROW) on MySQL 8 which both ensures that auto-increment values are assigned in a predictable and repeatable order ​as explained in the docs and thus allows for this feature to be used in setups using default InnoDB configurations.

[Mariusz Felisiak]

Thanks, it's worth trying. I think we can close it as a duplicate of #19527.