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| author | jonathan vanasco <jonathan@2xlp.com> | 2021-09-27 15:15:33 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-11-09 11:34:48 -0500 |
| commit | b2df5be7ee8b5ee7ae67323b5018ca37bbf0ce2a (patch) | |
| tree | 2abd440bff67b013bae396dd697a1e2f10fe0b17 /doc | |
| parent | cf404d840c15fe167518dd884b295dc99ee26178 (diff) | |
| download | sqlalchemy-b2df5be7ee8b5ee7ae67323b5018ca37bbf0ce2a.tar.gz | |
Deprecate create_engine.implicit_returning
The :paramref:`_sa.create_engine.implicit_returning` parameter is
deprecated on the :func:`_sa.create_engine` function only; the parameter
remains available on the :class:`_schema.Table` object. This parameter was
originally intended to enable the "implicit returning" feature of
SQLAlchemy when it was first developed and was not enabled by default.
Under modern use, there's no reason this parameter should be disabled, and
it has been observed to cause confusion as it degrades performance and
makes it more difficult for the ORM to retrieve recently inserted server
defaults. The parameter remains available on :class:`_schema.Table` to
specifically suit database-level edge cases which make RETURNING
infeasible, the sole example currently being SQL Server's limitation that
INSERT RETURNING may not be used on a table that has INSERT triggers on it.
Also removed from the Oracle dialect some logic that would upgrade
an Oracle 8/8i server version to use implicit returning if the
parameter were explictly passed; these versions of Oracle
still support RETURNING so the feature is now enabled for all
Oracle versions.
Fixes: #6962
Change-Id: Ib338e300cd7c8026c3083043f645084a8211aed8
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/build/changelog/unreleased_20/6962.rst | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/doc/build/changelog/unreleased_20/6962.rst b/doc/build/changelog/unreleased_20/6962.rst new file mode 100644 index 000000000..fcc3c1997 --- /dev/null +++ b/doc/build/changelog/unreleased_20/6962.rst @@ -0,0 +1,28 @@ +.. change:: + :tags: deprecations, engine + :tickets: 6962 + + The :paramref:`_sa.create_engine.implicit_returning` parameter is + deprecated on the :func:`_sa.create_engine` function only; the parameter + remains available on the :class:`_schema.Table` object. This parameter was + originally intended to enable the "implicit returning" feature of + SQLAlchemy when it was first developed and was not enabled by default. + Under modern use, there's no reason this parameter should be disabled, and + it has been observed to cause confusion as it degrades performance and + makes it more difficult for the ORM to retrieve recently inserted server + defaults. The parameter remains available on :class:`_schema.Table` to + specifically suit database-level edge cases which make RETURNING + infeasible, the sole example currently being SQL Server's limitation that + INSERT RETURNING may not be used on a table that has INSERT triggers on it. + + +.. change:: + :tags: bug, oracle + :tickets: 6962 + + Related to the deprecation for + :paramref:`_sa.create_engine.implicit_returning`, the "implicit_returning" + feature is now enabled for the Oracle dialect in all cases; previously, the + feature would be turned off when an Oracle 8/8i version were detected, + however online documentation indicates both versions support the same + RETURNING syntax as modern versions. |