From https://www.sqlite.org/partialindex.html
> Partial indexes have been supported in SQLite since version 3.8.0.
Reflection does not expose the predicate of partial indexes. The
postgresql dialect does detect such indexes and issue a warning. I
looked into matching this level of support, but the sqlite pragma
index_info does not expose the predicate. Getting this data would
probably require parsing the CREATE INDEX statement from sqlite_master.
logic to some degree in DefaultExecutionContext. In particular
we are removing post_insert() which doesn't appear to be used
based on a survey of prominent third party dialects. Callcounts
aren't added to existing execute profiling tests and inserts might be
a little better.
- simplify the execution_options join in DEC. Callcounts don't
appear affected.
levels; :meth:`.Connection.get_isolation_level`,
:attr:`.Connection.default_isolation_level`.
- enhance documentation inter-linkage between new accessors,
existing isolation_level parameters, as well as in
the dialect-level methods which should be fully covered
by Engine/Connection level APIs now.
:meth:`.Session.get_bind` method when calling upon
:meth:`.Query.count`, :meth:`.Query.update`, :meth:`.Query.delete`,
as well as queries against mapped columns,
:obj:`.column_property` objects, and SQL functions and expressions
derived from mapped columns. This allows sessions that rely upon
either customized :meth:`.Session.get_bind` schemes or "bound" metadata
to work in all relevant cases.
fixes#3227fixes#3242fixes#1326
now be constructed such that the visit methods receive an indication
of the owning expression object, if any. Any visit method that
accepts keyword arguments (e.g. ``**kw``) will in most cases
receive a keyword argument ``type_expression``, referring to the
expression object that the type is contained within. For columns
in DDL, the dialect's compiler class may need to alter its
``get_column_specification()`` method to support this as well.
The ``UserDefinedType.get_col_spec()`` method will also receive
``type_expression`` if it provides ``**kw`` in its argument
signature.
fixes#3074
expression in an :class:`.Index` that did not correspond directly
to a table-bound column; typically when a :func:`.text` construct
was one of the expressions within the index; or could misinterpret the
list of expressions if one or more of them were such an expression.
fixes#3174
the :func:`.orm.load_only` option to cover all attributes not
explicitly mentioned, now takes into account the superclasses
of a given entity, if that entity is mapped with inheritance mapping,
so that attribute names within the superclasses are also omitted
from the load. Additionally, the polymorphic discriminator column
is unconditionally included in the list, just in the same way that
primary key columns are, so that even with load_only() set up,
polymorphic loading of subtypes continues to function correctly.
fixes#3287
repaired to work more usefully with tables that have Python-
side default values and/or functions, as well as server-side
defaults. The feature will now work with a dialect that uses
"positional" parameters; a Python callable will also be
invoked individually for each row just as is the case with an
"executemany" style invocation; a server- side default column
will no longer implicitly receive the value explicitly
specified for the first row, instead refusing to invoke
without an explicit value. fixes#3288
:class:`.Query` before it fetched results, particularly when
row processors can't be formed, the cursor would stay open with
results pending and not actually be closed. This is typically only
an issue on an interpreter like Pypy where the cursor isn't
immediately GC'ed, and can in some circumstances lead to transactions/
locks being open longer than is desirable.
fixes#3285
of ``__slots__`` for many internal objects. This optimization is
particularly geared towards the base memory size of large applications
that have lots of tables and columns, and greatly reduces memory
size for a variety of high-volume objects including event listening
internals, comparator objects and parts of the ORM attribute and
loader strategy system.
to start up listener collections; this pulls the overhead off of construction
and makes performance much like the descriptor version, while still allowing
slots. Fix up some profiles.
assume that the empty string, or a set with a single empty string
value, is in fact a set with a single empty string; instead, this
is by default treated as the empty set. In order to handle persistence
of a :class:`.mysql.SET` that actually wants to include the blank
value ``''`` as a legitimate value, a new bitwise operational mode
is added which is enabled by the
:paramref:`.mysql.SET.retrieve_as_bitwise` flag, which will persist
and retrieve values unambiguously using their bitflag positioning.
Storage and retrieval of unicode values for driver configurations
that aren't converting unicode natively is also repaired.
fixes#3283
Mike Bayer