Fixed an issue in the ``CacheKey.to_offline_string()`` method used by the
dogpile.caching example where attempting to create a proper cache key from
the special "lambda" query generated by the lazy loader would fail to
include the parameter values, leading to an incorrect cache key.

Fixes: #6858
Change-Id: Ice27087583c6f3ff79cf7d5b879e5dd0a4e58158

Fixed further regressions in the same area as that of :ticket:`6052` where
loader options as well as invocations of methods like
:meth:`_orm.Query.join` would fail if the left side of the statement for
which the option/join depends upon were replaced by using the
:meth:`_orm.Query.with_entities` method, or when using 2.0 style queries
when using the :meth:`_sql.Select.with_only_columns` method. A new set of
state has been added to the objects which tracks the "left" entities that
the options / join were made against which is memoized when the lead
entities are changed.

Fixes: #6503
Fixes: #6253
Change-Id: I211b2af98b0b20d1263fb15dc513884dcc5de6a4

Fixed regression involving clause adaption of labeled ORM compound
elements, such as single-table inheritance discriminator expressions with
conditionals or CASE expressions, which could cause aliased expressions
such as those used in ORM join / joinedload operations to not be adapted
correctly, such as referring to the wrong table in the ON clause in a join.

This change also improves a performance bump that was located within the
process of invoking :meth:`_sql.Select.join` given an ORM attribute
as a target.

Fixes: #6550
Change-Id: I98906476f0cce6f41ea00b77c789baa818e9d167

Fixed issue in subquery loader strategy which prevented caching from
working correctly. This would have been seen in the logs as a "generated"
message instead of "cached" for all subqueryload SQL emitted, which by
saturating the cache with new keys would degrade overall performance; it
also would produce "LRU size alert" warnings.

In this issue we also observe that the local LRU cache for lazyloader
and selectinloader will get used for all subsequent loads as well,
which makes it more likely to hit the limit of 30.   However rather than
trying to work this out, it would be better if we removed the
loader-local LRU caches altogether once we are confident these
are working well.

Fixes: #6459
Change-Id: Id953e8f75536bb87f7e3315929cebcd8f84a5a50

The :class:`.TypeDecorator` class will now emit a warning when used in SQL
compilation with caching unless the ``.cache_ok`` flag is set to ``True``
or ``False``. ``.cache_ok`` indicates that all the parameters passed to the
object are safe to be used as a cache key, ``False`` means they are not.

Fixes: #6436
Change-Id: Ib1bb7dc4b124e38521d615c2e2e691e4915594fb

Fixed critical issue in the new :meth:`_orm.PropComparator.and_` feature
where loader strategies that emit secondary SELECT statements such as
:func:`_orm.selectinload` and :func:`_orm.lazyload` would fail to
accommodate for bound parameters in the user-defined criteria in terms of
the current statement being executed, as opposed to the cached statement,
causing stale bound values to be used.

This also adds a warning for the case where an object that uses
:func:`_orm.lazyload` in conjunction with :meth:`_orm.PropComparator.and_`
is attempted to be serialized; the loader criteria cannot reliably
be serialized and deserialized and eager loading should be used for this
case.

Fixes: #6139
Change-Id: I5a638bbecb7b583db2d3c0b76469f5a25c13dd3b

Fixed a critical regression in the relationship lazy loader where the SQL
criteria used to fetch a related many-to-one object could go stale in
relation to other memoized structures within the loader if the mapper had
configuration changes, such as can occur when mappers are late configured
or configured on demand, producing a comparison to None and returning no
object. Huge thanks to Alan Hamlett for their help tracking this down late
into the night.

The primary change is that mapper._get_clause() uses a fixed name
for its bound parameters, which is memoized under a lambda statement
in the case of many-to-one lazy loading.  This has implications for some other
logic namely the .compare() used by loader strategies to determine
use_get needed to be adjusted.

This change also repairs the lambda module's behavior of removing
the "required" flag from bound parameters, which caused this issue
to also fail silently rather than issuing an error for a required
bind parameter.

Fixes: #6055
Change-Id: I19e1aba9207a049873e0f13c19bad7541e223cfd

Implemented support for "table valued functions" along with additional
syntaxes supported by PostgreSQL, one of the most commonly requested
features. Table valued functions are SQL functions that return lists of
values or rows, and are prevalent in PostgreSQL in the area of JSON
functions, where the "table value" is commonly referred towards as the
"record" datatype. Table valued functions are also supported by Oracle and
SQL Server.

Moved from I5b093b72533ef695293e737eb75850b9713e5e03 due
to accidental push

Fixes: #3566
Change-Id: Iea36d04c80a5ed3509dcdd9ebf0701687143fef5

This also introduces that the "orm" plugin may be used
when the plugin_subject is None.

Fixed regression where the :paramref:`.Bundle.single_entity` flag would
take effect for a :class:`.Bundle` even though it were not set.
Additionally, this flag is legacy as it only makes sense for the
:class:`_orm.Query` object and not 2.0 style execution.  a deprecation
warning is emitted when used with new-style execution.

Fixes: #5702
Change-Id: If9f43365b9d966cb398890aeba2efa555658a7e5

* Fix subclass traversals to not run classes multiple times

* switch compiler visitor to use an attrgetter, to avoid
  an eval() at startup time

* don't pre-generate traversal functions, there's lots of these
  which are expensive to generate at once and most applications
  won't use them all; have it generate them on first use instead

* Some ideas about removing asyncio imports, they don't seem to
  be too signficant, apply some more simplicity to the overall
  "greenlet fallback" situation

Fixes: #5681
Change-Id: Ib564ddaddb374787ce3e11ff48026e99ed570933