2.0.43

Released: August 11, 2025

orm

[orm] [bug] Fixed issue where using the post_update feature would apply incorrect
"pre-fetched" values to the ORM objects after a multi-row UPDATE process
completed. These "pre-fetched" values would come from any column that had
an Column.onupdate callable or a version id generator used by
orm.Mapper.version_id_generator; for a version id generator
that delivered random identifiers like timestamps or UUIDs, this incorrect
data would lead to a DELETE statement against those same rows to fail in
the next step.

References: #12748
[orm] [bug] Fixed issue where _orm.mapped_column.use_existing_column
parameter in _orm.mapped_column() would not work when the
_orm.mapped_column() is used inside of an Annotated type alias in
polymorphic inheritance scenarios. The parameter is now properly recognized
and processed during declarative mapping configuration.

References: #12787
[orm] [bug] Improved the implementation of the _orm.selectin_polymorphic()
inheritance loader strategy to properly render the IN expressions using
chunks of 500 records each, in the same manner as that of the
_orm.selectinload() relationship loader strategy. Previously, the IN
expression would be arbitrarily large, leading to failures on databases
that have limits on the size of IN expressions including Oracle Database.

References: #12790

[engine] [usecase] Added new parameter create_engine.skip_autocommit_rollback
which provides for a per-dialect feature of preventing the DBAPI
.rollback() from being called under any circumstances, if the
connection is detected as being in "autocommit" mode. This improves upon
a critical performance issue identified in MySQL dialects where the network
overhead of the .rollback() call remains prohibitive even if autocommit
mode is set.

References: #12784

[postgresql] [bug] Fixed regression in PostgreSQL dialect where JSONB subscription syntax
would generate incorrect SQL for JSONB-returning functions, causing syntax
errors. The dialect now properly wraps function calls and expressions in
parentheses when using the [] subscription syntax, generating
(function_call)[index] instead of function_call[index] to comply
with PostgreSQL syntax requirements.

References: #12778

[oracle] [usecase] Extended _oracle.VECTOR to support sparse vectors. This update
introduces _oracle.VectorStorageType to specify sparse or dense
storage and added _oracle.SparseVector. Pull request courtesy
Suraj Shaw.

References: #12711