[FIX] core: searching through o2m with auto_join

Replaces the auto_join scheme which is pretty fast but doesn't quite
work (it's *completely* broken for read_group) by a subquery which is
slower but has the same semantics as the ORM version.

Ideally we'd use `EXISTS (select 1 from ...)` but that has no support
inside the SQL compiler right now, so use `id in (select inverse_field
from ...)`.

Here are some measures of a `read_group` on a simple object with lines
filtered on line values, similar to

    read_group([('order_line.product_uom', '=', xxx)],
               fields=['total_amount'], groupby=['user_id'])

    +-------+-------+-------+--------+
    |       |   ORM |  join |subquery|
    +-------+-------+-------+--------+
    | large |   160 |    10 |     20 |
    +-------+-------+-------+--------+
    |  many | 36000 |    50 |    180 |
    +-------+-------+-------+--------+

* values of data fields (filtering, grouping and aggregating) randomly
picked between 10 different values
* "large" is 1000 objects with 1000~15000 lines each
* "many" is 1000000 objects with 1~40 lines each

closes odoo/odoo#48494

Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

0 files changed, 0 insertions, 0 deletions