3c2065c89d
Avoid pathological performance issue caused by injecting ids retrieved with
another query.
Consider a domain like `[('m2m', 'in', ids)]` on a many2many field. The
current implementation will perform the subquery:
SELECT m2m_id1 FROM m2m_table WHERE m2m_id2 IN (ids)
and inject its result into the main query as:
SELECT id FROM ... WHERE id IN (result_ids)
The latter may be very slow if `result_ids` is a huge list of ids.
The fix injects the first query into the main query as:
SELECT id FROM ... WHERE id IN (
SELECT m2m_id1 FROM m2m_table WHERE m2m_id2 IN (ids)
)
As a result, the database will typically JOIN both tables, and avoid generating
the whole list from the subquery.
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| .. | ||
| __init__.py | ||
| expression.py | ||
| fields.py | ||
| orm.py | ||
| osv.py | ||
| query.py | ||