diff options
| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2022-11-13 21:48:53 -0500 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2022-11-15 14:16:06 -0500 |
| commit | d5be2cc1391d0ff4b21557b036eba4713fde7bcf (patch) | |
| tree | a50189a0e7cf8d8ff7f9d1081246d746347e1951 /lib/sqlalchemy/sql/schema.py | |
| parent | 93dc7ea1502c37793011b094447641361aff5aba (diff) | |
| download | sqlalchemy-d5be2cc1391d0ff4b21557b036eba4713fde7bcf.tar.gz | |
perf improvements related to corresponding_column (2)
commit two of two. this reorganizes ColumnCollection
to build a new index up front that's used to optimize
the corresponding_column() method.
Additional performance enhancements within ORM-enabled SQL statements,
specifically targeting callcounts within the construction of ORM
statements, using combinations of :func:`_orm.aliased` with
:func:`_sql.union` and similar "compound" constructs, in addition to direct
performance improvements to the ``corresponding_column()`` internal method
that is used heavily by the ORM by constructs like :func:`_orm.aliased` and
similar.
Fixes: #8796
Change-Id: I4a76788007d5a802b9a4081e6a0f6e4b52497b50
Diffstat (limited to 'lib/sqlalchemy/sql/schema.py')
| -rw-r--r-- | lib/sqlalchemy/sql/schema.py | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index dde5cd372..cd10d0c4a 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -2360,6 +2360,9 @@ class Column(DialectKWArgs, SchemaItem, ColumnClause[_T]): name: Optional[str] = None, key: Optional[str] = None, name_is_truncatable: bool = False, + compound_select_cols: Optional[ + _typing_Sequence[ColumnElement[Any]] + ] = None, **kw: Any, ) -> Tuple[str, ColumnClause[_T]]: """Create a *proxy* for this column. @@ -2401,7 +2404,9 @@ class Column(DialectKWArgs, SchemaItem, ColumnClause[_T]): key=key if key else name if name else self.key, primary_key=self.primary_key, nullable=self.nullable, - _proxies=[self], + _proxies=list(compound_select_cols) + if compound_select_cols + else [self], *fk, ) except TypeError as err: |