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+# ext/asyncio/engine.py
+# Copyright (C) 2020-2024 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+from __future__ import annotations
+
+import asyncio
+import contextlib
+from typing import Any
+from typing import AsyncIterator
+from typing import Callable
+from typing import Dict
+from typing import Generator
+from typing import NoReturn
+from typing import Optional
+from typing import overload
+from typing import Tuple
+from typing import Type
+from typing import TYPE_CHECKING
+from typing import TypeVar
+from typing import Union
+
+from . import exc as async_exc
+from .base import asyncstartablecontext
+from .base import GeneratorStartableContext
+from .base import ProxyComparable
+from .base import StartableContext
+from .result import _ensure_sync_result
+from .result import AsyncResult
+from .result import AsyncScalarResult
+from ... import exc
+from ... import inspection
+from ... import util
+from ...engine import Connection
+from ...engine import create_engine as _create_engine
+from ...engine import create_pool_from_url as _create_pool_from_url
+from ...engine import Engine
+from ...engine.base import NestedTransaction
+from ...engine.base import Transaction
+from ...exc import ArgumentError
+from ...util.concurrency import greenlet_spawn
+from ...util.typing import Concatenate
+from ...util.typing import ParamSpec
+
+if TYPE_CHECKING:
+    from ...engine.cursor import CursorResult
+    from ...engine.interfaces import _CoreAnyExecuteParams
+    from ...engine.interfaces import _CoreSingleExecuteParams
+    from ...engine.interfaces import _DBAPIAnyExecuteParams
+    from ...engine.interfaces import _ExecuteOptions
+    from ...engine.interfaces import CompiledCacheType
+    from ...engine.interfaces import CoreExecuteOptionsParameter
+    from ...engine.interfaces import Dialect
+    from ...engine.interfaces import IsolationLevel
+    from ...engine.interfaces import SchemaTranslateMapType
+    from ...engine.result import ScalarResult
+    from ...engine.url import URL
+    from ...pool import Pool
+    from ...pool import PoolProxiedConnection
+    from ...sql._typing import _InfoType
+    from ...sql.base import Executable
+    from ...sql.selectable import TypedReturnsRows
+
+_P = ParamSpec("_P")
+_T = TypeVar("_T", bound=Any)
+
+
+def create_async_engine(url: Union[str, URL], **kw: Any) -> AsyncEngine:
+    """Create a new async engine instance.
+
+    Arguments passed to :func:`_asyncio.create_async_engine` are mostly
+    identical to those passed to the :func:`_sa.create_engine` function.
+    The specified dialect must be an asyncio-compatible dialect
+    such as :ref:`dialect-postgresql-asyncpg`.
+
+    .. versionadded:: 1.4
+
+    :param async_creator: an async callable which returns a driver-level
+        asyncio connection. If given, the function should take no arguments,
+        and return a new asyncio connection from the underlying asyncio
+        database driver; the connection will be wrapped in the appropriate
+        structures to be used with the :class:`.AsyncEngine`.   Note that the
+        parameters specified in the URL are not applied here, and the creator
+        function should use its own connection parameters.
+
+        This parameter is the asyncio equivalent of the
+        :paramref:`_sa.create_engine.creator` parameter of the
+        :func:`_sa.create_engine` function.
+
+        .. versionadded:: 2.0.16
+
+    """
+
+    if kw.get("server_side_cursors", False):
+        raise async_exc.AsyncMethodRequired(
+            "Can't set server_side_cursors for async engine globally; "
+            "use the connection.stream() method for an async "
+            "streaming result set"
+        )
+    kw["_is_async"] = True
+    async_creator = kw.pop("async_creator", None)
+    if async_creator:
+        if kw.get("creator", None):
+            raise ArgumentError(
+                "Can only specify one of 'async_creator' or 'creator', "
+                "not both."
+            )
+
+        def creator() -> Any:
+            # note that to send adapted arguments like
+            # prepared_statement_cache_size, user would use
+            # "creator" and emulate this form here
+            return sync_engine.dialect.dbapi.connect(  # type: ignore
+                async_creator_fn=async_creator
+            )
+
+        kw["creator"] = creator
+    sync_engine = _create_engine(url, **kw)
+    return AsyncEngine(sync_engine)
+
+
+def async_engine_from_config(
+    configuration: Dict[str, Any], prefix: str = "sqlalchemy.", **kwargs: Any
+) -> AsyncEngine:
+    """Create a new AsyncEngine instance using a configuration dictionary.
+
+    This function is analogous to the :func:`_sa.engine_from_config` function
+    in SQLAlchemy Core, except that the requested dialect must be an
+    asyncio-compatible dialect such as :ref:`dialect-postgresql-asyncpg`.
+    The argument signature of the function is identical to that
+    of :func:`_sa.engine_from_config`.
+
+    .. versionadded:: 1.4.29
+
+    """
+    options = {
+        key[len(prefix) :]: value
+        for key, value in configuration.items()
+        if key.startswith(prefix)
+    }
+    options["_coerce_config"] = True
+    options.update(kwargs)
+    url = options.pop("url")
+    return create_async_engine(url, **options)
+
+
+def create_async_pool_from_url(url: Union[str, URL], **kwargs: Any) -> Pool:
+    """Create a new async engine instance.
+
+    Arguments passed to :func:`_asyncio.create_async_pool_from_url` are mostly
+    identical to those passed to the :func:`_sa.create_pool_from_url` function.
+    The specified dialect must be an asyncio-compatible dialect
+    such as :ref:`dialect-postgresql-asyncpg`.
+
+    .. versionadded:: 2.0.10
+
+    """
+    kwargs["_is_async"] = True
+    return _create_pool_from_url(url, **kwargs)
+
+
+class AsyncConnectable:
+    __slots__ = "_slots_dispatch", "__weakref__"
+
+    @classmethod
+    def _no_async_engine_events(cls) -> NoReturn:
+        raise NotImplementedError(
+            "asynchronous events are not implemented at this time.  Apply "
+            "synchronous listeners to the AsyncEngine.sync_engine or "
+            "AsyncConnection.sync_connection attributes."
+        )
+
+
+@util.create_proxy_methods(
+    Connection,
+    ":class:`_engine.Connection`",
+    ":class:`_asyncio.AsyncConnection`",
+    classmethods=[],
+    methods=[],
+    attributes=[
+        "closed",
+        "invalidated",
+        "dialect",
+        "default_isolation_level",
+    ],
+)
+class AsyncConnection(
+    ProxyComparable[Connection],
+    StartableContext["AsyncConnection"],
+    AsyncConnectable,
+):
+    """An asyncio proxy for a :class:`_engine.Connection`.
+
+    :class:`_asyncio.AsyncConnection` is acquired using the
+    :meth:`_asyncio.AsyncEngine.connect`
+    method of :class:`_asyncio.AsyncEngine`::
+
+        from sqlalchemy.ext.asyncio import create_async_engine
+        engine = create_async_engine("postgresql+asyncpg://user:pass@host/dbname")
+
+        async with engine.connect() as conn:
+            result = await conn.execute(select(table))
+
+    .. versionadded:: 1.4
+
+    """  # noqa
+
+    # AsyncConnection is a thin proxy; no state should be added here
+    # that is not retrievable from the "sync" engine / connection, e.g.
+    # current transaction, info, etc.   It should be possible to
+    # create a new AsyncConnection that matches this one given only the
+    # "sync" elements.
+    __slots__ = (
+        "engine",
+        "sync_engine",
+        "sync_connection",
+    )
+
+    def __init__(
+        self,
+        async_engine: AsyncEngine,
+        sync_connection: Optional[Connection] = None,
+    ):
+        self.engine = async_engine
+        self.sync_engine = async_engine.sync_engine
+        self.sync_connection = self._assign_proxied(sync_connection)
+
+    sync_connection: Optional[Connection]
+    """Reference to the sync-style :class:`_engine.Connection` this
+    :class:`_asyncio.AsyncConnection` proxies requests towards.
+
+    This instance can be used as an event target.
+
+    .. seealso::
+
+        :ref:`asyncio_events`
+
+    """
+
+    sync_engine: Engine
+    """Reference to the sync-style :class:`_engine.Engine` this
+    :class:`_asyncio.AsyncConnection` is associated with via its underlying
+    :class:`_engine.Connection`.
+
+    This instance can be used as an event target.
+
+    .. seealso::
+
+        :ref:`asyncio_events`
+
+    """
+
+    @classmethod
+    def _regenerate_proxy_for_target(
+        cls, target: Connection
+    ) -> AsyncConnection:
+        return AsyncConnection(
+            AsyncEngine._retrieve_proxy_for_target(target.engine), target
+        )
+
+    async def start(
+        self, is_ctxmanager: bool = False  # noqa: U100
+    ) -> AsyncConnection:
+        """Start this :class:`_asyncio.AsyncConnection` object's context
+        outside of using a Python ``with:`` block.
+
+        """
+        if self.sync_connection:
+            raise exc.InvalidRequestError("connection is already started")
+        self.sync_connection = self._assign_proxied(
+            await greenlet_spawn(self.sync_engine.connect)
+        )
+        return self
+
+    @property
+    def connection(self) -> NoReturn:
+        """Not implemented for async; call
+        :meth:`_asyncio.AsyncConnection.get_raw_connection`.
+        """
+        raise exc.InvalidRequestError(
+            "AsyncConnection.connection accessor is not implemented as the "
+            "attribute may need to reconnect on an invalidated connection.  "
+            "Use the get_raw_connection() method."
+        )
+
+    async def get_raw_connection(self) -> PoolProxiedConnection:
+        """Return the pooled DBAPI-level connection in use by this
+        :class:`_asyncio.AsyncConnection`.
+
+        This is a SQLAlchemy connection-pool proxied connection
+        which then has the attribute
+        :attr:`_pool._ConnectionFairy.driver_connection` that refers to the
+        actual driver connection. Its
+        :attr:`_pool._ConnectionFairy.dbapi_connection` refers instead
+        to an :class:`_engine.AdaptedConnection` instance that
+        adapts the driver connection to the DBAPI protocol.
+
+        """
+
+        return await greenlet_spawn(getattr, self._proxied, "connection")
+
+    @util.ro_non_memoized_property
+    def info(self) -> _InfoType:
+        """Return the :attr:`_engine.Connection.info` dictionary of the
+        underlying :class:`_engine.Connection`.
+
+        This dictionary is freely writable for user-defined state to be
+        associated with the database connection.
+
+        This attribute is only available if the :class:`.AsyncConnection` is
+        currently connected.   If the :attr:`.AsyncConnection.closed` attribute
+        is ``True``, then accessing this attribute will raise
+        :class:`.ResourceClosedError`.
+
+        .. versionadded:: 1.4.0b2
+
+        """
+        return self._proxied.info
+
+    @util.ro_non_memoized_property
+    def _proxied(self) -> Connection:
+        if not self.sync_connection:
+            self._raise_for_not_started()
+        return self.sync_connection
+
+    def begin(self) -> AsyncTransaction:
+        """Begin a transaction prior to autobegin occurring."""
+        assert self._proxied
+        return AsyncTransaction(self)
+
+    def begin_nested(self) -> AsyncTransaction:
+        """Begin a nested transaction and return a transaction handle."""
+        assert self._proxied
+        return AsyncTransaction(self, nested=True)
+
+    async def invalidate(
+        self, exception: Optional[BaseException] = None
+    ) -> None:
+        """Invalidate the underlying DBAPI connection associated with
+        this :class:`_engine.Connection`.
+
+        See the method :meth:`_engine.Connection.invalidate` for full
+        detail on this method.
+
+        """
+
+        return await greenlet_spawn(
+            self._proxied.invalidate, exception=exception
+        )
+
+    async def get_isolation_level(self) -> IsolationLevel:
+        return await greenlet_spawn(self._proxied.get_isolation_level)
+
+    def in_transaction(self) -> bool:
+        """Return True if a transaction is in progress."""
+
+        return self._proxied.in_transaction()
+
+    def in_nested_transaction(self) -> bool:
+        """Return True if a transaction is in progress.
+
+        .. versionadded:: 1.4.0b2
+
+        """
+        return self._proxied.in_nested_transaction()
+
+    def get_transaction(self) -> Optional[AsyncTransaction]:
+        """Return an :class:`.AsyncTransaction` representing the current
+        transaction, if any.
+
+        This makes use of the underlying synchronous connection's
+        :meth:`_engine.Connection.get_transaction` method to get the current
+        :class:`_engine.Transaction`, which is then proxied in a new
+        :class:`.AsyncTransaction` object.
+
+        .. versionadded:: 1.4.0b2
+
+        """
+
+        trans = self._proxied.get_transaction()
+        if trans is not None:
+            return AsyncTransaction._retrieve_proxy_for_target(trans)
+        else:
+            return None
+
+    def get_nested_transaction(self) -> Optional[AsyncTransaction]:
+        """Return an :class:`.AsyncTransaction` representing the current
+        nested (savepoint) transaction, if any.
+
+        This makes use of the underlying synchronous connection's
+        :meth:`_engine.Connection.get_nested_transaction` method to get the
+        current :class:`_engine.Transaction`, which is then proxied in a new
+        :class:`.AsyncTransaction` object.
+
+        .. versionadded:: 1.4.0b2
+
+        """
+
+        trans = self._proxied.get_nested_transaction()
+        if trans is not None:
+            return AsyncTransaction._retrieve_proxy_for_target(trans)
+        else:
+            return None
+
+    @overload
+    async def execution_options(
+        self,
+        *,
+        compiled_cache: Optional[CompiledCacheType] = ...,
+        logging_token: str = ...,
+        isolation_level: IsolationLevel = ...,
+        no_parameters: bool = False,
+        stream_results: bool = False,
+        max_row_buffer: int = ...,
+        yield_per: int = ...,
+        insertmanyvalues_page_size: int = ...,
+        schema_translate_map: Optional[SchemaTranslateMapType] = ...,
+        preserve_rowcount: bool = False,
+        **opt: Any,
+    ) -> AsyncConnection: ...
+
+    @overload
+    async def execution_options(self, **opt: Any) -> AsyncConnection: ...
+
+    async def execution_options(self, **opt: Any) -> AsyncConnection:
+        r"""Set non-SQL options for the connection which take effect
+        during execution.
+
+        This returns this :class:`_asyncio.AsyncConnection` object with
+        the new options added.
+
+        See :meth:`_engine.Connection.execution_options` for full details
+        on this method.
+
+        """
+
+        conn = self._proxied
+        c2 = await greenlet_spawn(conn.execution_options, **opt)
+        assert c2 is conn
+        return self
+
+    async def commit(self) -> None:
+        """Commit the transaction that is currently in progress.
+
+        This method commits the current transaction if one has been started.
+        If no transaction was started, the method has no effect, assuming
+        the connection is in a non-invalidated state.
+
+        A transaction is begun on a :class:`_engine.Connection` automatically
+        whenever a statement is first executed, or when the
+        :meth:`_engine.Connection.begin` method is called.
+
+        """
+        await greenlet_spawn(self._proxied.commit)
+
+    async def rollback(self) -> None:
+        """Roll back the transaction that is currently in progress.
+
+        This method rolls back the current transaction if one has been started.
+        If no transaction was started, the method has no effect.  If a
+        transaction was started and the connection is in an invalidated state,
+        the transaction is cleared using this method.
+
+        A transaction is begun on a :class:`_engine.Connection` automatically
+        whenever a statement is first executed, or when the
+        :meth:`_engine.Connection.begin` method is called.
+
+
+        """
+        await greenlet_spawn(self._proxied.rollback)
+
+    async def close(self) -> None:
+        """Close this :class:`_asyncio.AsyncConnection`.
+
+        This has the effect of also rolling back the transaction if one
+        is in place.
+
+        """
+        await greenlet_spawn(self._proxied.close)
+
+    async def aclose(self) -> None:
+        """A synonym for :meth:`_asyncio.AsyncConnection.close`.
+
+        The :meth:`_asyncio.AsyncConnection.aclose` name is specifically
+        to support the Python standard library ``@contextlib.aclosing``
+        context manager function.
+
+        .. versionadded:: 2.0.20
+
+        """
+        await self.close()
+
+    async def exec_driver_sql(
+        self,
+        statement: str,
+        parameters: Optional[_DBAPIAnyExecuteParams] = None,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> CursorResult[Any]:
+        r"""Executes a driver-level SQL string and return buffered
+        :class:`_engine.Result`.
+
+        """
+
+        result = await greenlet_spawn(
+            self._proxied.exec_driver_sql,
+            statement,
+            parameters,
+            execution_options,
+            _require_await=True,
+        )
+
+        return await _ensure_sync_result(result, self.exec_driver_sql)
+
+    @overload
+    def stream(
+        self,
+        statement: TypedReturnsRows[_T],
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> GeneratorStartableContext[AsyncResult[_T]]: ...
+
+    @overload
+    def stream(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> GeneratorStartableContext[AsyncResult[Any]]: ...
+
+    @asyncstartablecontext
+    async def stream(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> AsyncIterator[AsyncResult[Any]]:
+        """Execute a statement and return an awaitable yielding a
+        :class:`_asyncio.AsyncResult` object.
+
+        E.g.::
+
+            result = await conn.stream(stmt):
+            async for row in result:
+                print(f"{row}")
+
+        The :meth:`.AsyncConnection.stream`
+        method supports optional context manager use against the
+        :class:`.AsyncResult` object, as in::
+
+            async with conn.stream(stmt) as result:
+                async for row in result:
+                    print(f"{row}")
+
+        In the above pattern, the :meth:`.AsyncResult.close` method is
+        invoked unconditionally, even if the iterator is interrupted by an
+        exception throw.   Context manager use remains optional, however,
+        and the function may be called in either an ``async with fn():`` or
+        ``await fn()`` style.
+
+        .. versionadded:: 2.0.0b3 added context manager support
+
+
+        :return: an awaitable object that will yield an
+         :class:`_asyncio.AsyncResult` object.
+
+        .. seealso::
+
+            :meth:`.AsyncConnection.stream_scalars`
+
+        """
+        if not self.dialect.supports_server_side_cursors:
+            raise exc.InvalidRequestError(
+                "Cant use `stream` or `stream_scalars` with the current "
+                "dialect since it does not support server side cursors."
+            )
+
+        result = await greenlet_spawn(
+            self._proxied.execute,
+            statement,
+            parameters,
+            execution_options=util.EMPTY_DICT.merge_with(
+                execution_options, {"stream_results": True}
+            ),
+            _require_await=True,
+        )
+        assert result.context._is_server_side
+        ar = AsyncResult(result)
+        try:
+            yield ar
+        except GeneratorExit:
+            pass
+        else:
+            task = asyncio.create_task(ar.close())
+            await asyncio.shield(task)
+
+    @overload
+    async def execute(
+        self,
+        statement: TypedReturnsRows[_T],
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> CursorResult[_T]: ...
+
+    @overload
+    async def execute(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> CursorResult[Any]: ...
+
+    async def execute(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> CursorResult[Any]:
+        r"""Executes a SQL statement construct and return a buffered
+        :class:`_engine.Result`.
+
+        :param object: The statement to be executed.  This is always
+         an object that is in both the :class:`_expression.ClauseElement` and
+         :class:`_expression.Executable` hierarchies, including:
+
+         * :class:`_expression.Select`
+         * :class:`_expression.Insert`, :class:`_expression.Update`,
+           :class:`_expression.Delete`
+         * :class:`_expression.TextClause` and
+           :class:`_expression.TextualSelect`
+         * :class:`_schema.DDL` and objects which inherit from
+           :class:`_schema.ExecutableDDLElement`
+
+        :param parameters: parameters which will be bound into the statement.
+         This may be either a dictionary of parameter names to values,
+         or a mutable sequence (e.g. a list) of dictionaries.  When a
+         list of dictionaries is passed, the underlying statement execution
+         will make use of the DBAPI ``cursor.executemany()`` method.
+         When a single dictionary is passed, the DBAPI ``cursor.execute()``
+         method will be used.
+
+        :param execution_options: optional dictionary of execution options,
+         which will be associated with the statement execution.  This
+         dictionary can provide a subset of the options that are accepted
+         by :meth:`_engine.Connection.execution_options`.
+
+        :return: a :class:`_engine.Result` object.
+
+        """
+        result = await greenlet_spawn(
+            self._proxied.execute,
+            statement,
+            parameters,
+            execution_options=execution_options,
+            _require_await=True,
+        )
+        return await _ensure_sync_result(result, self.execute)
+
+    @overload
+    async def scalar(
+        self,
+        statement: TypedReturnsRows[Tuple[_T]],
+        parameters: Optional[_CoreSingleExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> Optional[_T]: ...
+
+    @overload
+    async def scalar(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreSingleExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> Any: ...
+
+    async def scalar(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreSingleExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> Any:
+        r"""Executes a SQL statement construct and returns a scalar object.
+
+        This method is shorthand for invoking the
+        :meth:`_engine.Result.scalar` method after invoking the
+        :meth:`_engine.Connection.execute` method.  Parameters are equivalent.
+
+        :return: a scalar Python value representing the first column of the
+         first row returned.
+
+        """
+        result = await self.execute(
+            statement, parameters, execution_options=execution_options
+        )
+        return result.scalar()
+
+    @overload
+    async def scalars(
+        self,
+        statement: TypedReturnsRows[Tuple[_T]],
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> ScalarResult[_T]: ...
+
+    @overload
+    async def scalars(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> ScalarResult[Any]: ...
+
+    async def scalars(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreAnyExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> ScalarResult[Any]:
+        r"""Executes a SQL statement construct and returns a scalar objects.
+
+        This method is shorthand for invoking the
+        :meth:`_engine.Result.scalars` method after invoking the
+        :meth:`_engine.Connection.execute` method.  Parameters are equivalent.
+
+        :return: a :class:`_engine.ScalarResult` object.
+
+        .. versionadded:: 1.4.24
+
+        """
+        result = await self.execute(
+            statement, parameters, execution_options=execution_options
+        )
+        return result.scalars()
+
+    @overload
+    def stream_scalars(
+        self,
+        statement: TypedReturnsRows[Tuple[_T]],
+        parameters: Optional[_CoreSingleExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> GeneratorStartableContext[AsyncScalarResult[_T]]: ...
+
+    @overload
+    def stream_scalars(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreSingleExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> GeneratorStartableContext[AsyncScalarResult[Any]]: ...
+
+    @asyncstartablecontext
+    async def stream_scalars(
+        self,
+        statement: Executable,
+        parameters: Optional[_CoreSingleExecuteParams] = None,
+        *,
+        execution_options: Optional[CoreExecuteOptionsParameter] = None,
+    ) -> AsyncIterator[AsyncScalarResult[Any]]:
+        r"""Execute a statement and return an awaitable yielding a
+        :class:`_asyncio.AsyncScalarResult` object.
+
+        E.g.::
+
+            result = await conn.stream_scalars(stmt)
+            async for scalar in result:
+                print(f"{scalar}")
+
+        This method is shorthand for invoking the
+        :meth:`_engine.AsyncResult.scalars` method after invoking the
+        :meth:`_engine.Connection.stream` method.  Parameters are equivalent.
+
+        The :meth:`.AsyncConnection.stream_scalars`
+        method supports optional context manager use against the
+        :class:`.AsyncScalarResult` object, as in::
+
+            async with conn.stream_scalars(stmt) as result:
+                async for scalar in result:
+                    print(f"{scalar}")
+
+        In the above pattern, the :meth:`.AsyncScalarResult.close` method is
+        invoked unconditionally, even if the iterator is interrupted by an
+        exception throw.  Context manager use remains optional, however,
+        and the function may be called in either an ``async with fn():`` or
+        ``await fn()`` style.
+
+        .. versionadded:: 2.0.0b3 added context manager support
+
+        :return: an awaitable object that will yield an
+         :class:`_asyncio.AsyncScalarResult` object.
+
+        .. versionadded:: 1.4.24
+
+        .. seealso::
+
+            :meth:`.AsyncConnection.stream`
+
+        """
+
+        async with self.stream(
+            statement, parameters, execution_options=execution_options
+        ) as result:
+            yield result.scalars()
+
+    async def run_sync(
+        self,
+        fn: Callable[Concatenate[Connection, _P], _T],
+        *arg: _P.args,
+        **kw: _P.kwargs,
+    ) -> _T:
+        """Invoke the given synchronous (i.e. not async) callable,
+        passing a synchronous-style :class:`_engine.Connection` as the first
+        argument.
+
+        This method allows traditional synchronous SQLAlchemy functions to
+        run within the context of an asyncio application.
+
+        E.g.::
+
+            def do_something_with_core(conn: Connection, arg1: int, arg2: str) -> str:
+                '''A synchronous function that does not require awaiting
+
+                :param conn: a Core SQLAlchemy Connection, used synchronously
+
+                :return: an optional return value is supported
+
+                '''
+                conn.execute(
+                    some_table.insert().values(int_col=arg1, str_col=arg2)
+                )
+                return "success"
+
+
+            async def do_something_async(async_engine: AsyncEngine) -> None:
+                '''an async function that uses awaiting'''
+
+                async with async_engine.begin() as async_conn:
+                    # run do_something_with_core() with a sync-style
+                    # Connection, proxied into an awaitable
+                    return_code = await async_conn.run_sync(do_something_with_core, 5, "strval")
+                    print(return_code)
+
+        This method maintains the asyncio event loop all the way through
+        to the database connection by running the given callable in a
+        specially instrumented greenlet.
+
+        The most rudimentary use of :meth:`.AsyncConnection.run_sync` is to
+        invoke methods such as :meth:`_schema.MetaData.create_all`, given
+        an :class:`.AsyncConnection` that needs to be provided to
+        :meth:`_schema.MetaData.create_all` as a :class:`_engine.Connection`
+        object::
+
+            # run metadata.create_all(conn) with a sync-style Connection,
+            # proxied into an awaitable
+            with async_engine.begin() as conn:
+                await conn.run_sync(metadata.create_all)
+
+        .. note::
+
+            The provided callable is invoked inline within the asyncio event
+            loop, and will block on traditional IO calls.  IO within this
+            callable should only call into SQLAlchemy's asyncio database
+            APIs which will be properly adapted to the greenlet context.
+
+        .. seealso::
+
+            :meth:`.AsyncSession.run_sync`
+
+            :ref:`session_run_sync`
+
+        """  # noqa: E501
+
+        return await greenlet_spawn(
+            fn, self._proxied, *arg, _require_await=False, **kw
+        )
+
+    def __await__(self) -> Generator[Any, None, AsyncConnection]:
+        return self.start().__await__()
+
+    async def __aexit__(self, type_: Any, value: Any, traceback: Any) -> None:
+        task = asyncio.create_task(self.close())
+        await asyncio.shield(task)
+
+    # START PROXY METHODS AsyncConnection
+
+    # code within this block is **programmatically,
+    # statically generated** by tools/generate_proxy_methods.py
+
+    @property
+    def closed(self) -> Any:
+        r"""Return True if this connection is closed.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Connection` class
+            on behalf of the :class:`_asyncio.AsyncConnection` class.
+
+        """  # noqa: E501
+
+        return self._proxied.closed
+
+    @property
+    def invalidated(self) -> Any:
+        r"""Return True if this connection was invalidated.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Connection` class
+            on behalf of the :class:`_asyncio.AsyncConnection` class.
+
+        This does not indicate whether or not the connection was
+        invalidated at the pool level, however
+
+
+        """  # noqa: E501
+
+        return self._proxied.invalidated
+
+    @property
+    def dialect(self) -> Dialect:
+        r"""Proxy for the :attr:`_engine.Connection.dialect` attribute
+        on behalf of the :class:`_asyncio.AsyncConnection` class.
+
+        """  # noqa: E501
+
+        return self._proxied.dialect
+
+    @dialect.setter
+    def dialect(self, attr: Dialect) -> None:
+        self._proxied.dialect = attr
+
+    @property
+    def default_isolation_level(self) -> Any:
+        r"""The initial-connection time isolation level associated with the
+        :class:`_engine.Dialect` in use.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Connection` class
+            on behalf of the :class:`_asyncio.AsyncConnection` class.
+
+        This value is independent of the
+        :paramref:`.Connection.execution_options.isolation_level` and
+        :paramref:`.Engine.execution_options.isolation_level` execution
+        options, and is determined by the :class:`_engine.Dialect` when the
+        first connection is created, by performing a SQL query against the
+        database for the current isolation level before any additional commands
+        have been emitted.
+
+        Calling this accessor does not invoke any new SQL queries.
+
+        .. seealso::
+
+            :meth:`_engine.Connection.get_isolation_level`
+            - view current actual isolation level
+
+            :paramref:`_sa.create_engine.isolation_level`
+            - set per :class:`_engine.Engine` isolation level
+
+            :paramref:`.Connection.execution_options.isolation_level`
+            - set per :class:`_engine.Connection` isolation level
+
+
+        """  # noqa: E501
+
+        return self._proxied.default_isolation_level
+
+    # END PROXY METHODS AsyncConnection
+
+
+@util.create_proxy_methods(
+    Engine,
+    ":class:`_engine.Engine`",
+    ":class:`_asyncio.AsyncEngine`",
+    classmethods=[],
+    methods=[
+        "clear_compiled_cache",
+        "update_execution_options",
+        "get_execution_options",
+    ],
+    attributes=["url", "pool", "dialect", "engine", "name", "driver", "echo"],
+)
+class AsyncEngine(ProxyComparable[Engine], AsyncConnectable):
+    """An asyncio proxy for a :class:`_engine.Engine`.
+
+    :class:`_asyncio.AsyncEngine` is acquired using the
+    :func:`_asyncio.create_async_engine` function::
+
+        from sqlalchemy.ext.asyncio import create_async_engine
+        engine = create_async_engine("postgresql+asyncpg://user:pass@host/dbname")
+
+    .. versionadded:: 1.4
+
+    """  # noqa
+
+    # AsyncEngine is a thin proxy; no state should be added here
+    # that is not retrievable from the "sync" engine / connection, e.g.
+    # current transaction, info, etc.   It should be possible to
+    # create a new AsyncEngine that matches this one given only the
+    # "sync" elements.
+    __slots__ = "sync_engine"
+
+    _connection_cls: Type[AsyncConnection] = AsyncConnection
+
+    sync_engine: Engine
+    """Reference to the sync-style :class:`_engine.Engine` this
+    :class:`_asyncio.AsyncEngine` proxies requests towards.
+
+    This instance can be used as an event target.
+
+    .. seealso::
+
+        :ref:`asyncio_events`
+    """
+
+    def __init__(self, sync_engine: Engine):
+        if not sync_engine.dialect.is_async:
+            raise exc.InvalidRequestError(
+                "The asyncio extension requires an async driver to be used. "
+                f"The loaded {sync_engine.dialect.driver!r} is not async."
+            )
+        self.sync_engine = self._assign_proxied(sync_engine)
+
+    @util.ro_non_memoized_property
+    def _proxied(self) -> Engine:
+        return self.sync_engine
+
+    @classmethod
+    def _regenerate_proxy_for_target(cls, target: Engine) -> AsyncEngine:
+        return AsyncEngine(target)
+
+    @contextlib.asynccontextmanager
+    async def begin(self) -> AsyncIterator[AsyncConnection]:
+        """Return a context manager which when entered will deliver an
+        :class:`_asyncio.AsyncConnection` with an
+        :class:`_asyncio.AsyncTransaction` established.
+
+        E.g.::
+
+            async with async_engine.begin() as conn:
+                await conn.execute(
+                    text("insert into table (x, y, z) values (1, 2, 3)")
+                )
+                await conn.execute(text("my_special_procedure(5)"))
+
+
+        """
+        conn = self.connect()
+
+        async with conn:
+            async with conn.begin():
+                yield conn
+
+    def connect(self) -> AsyncConnection:
+        """Return an :class:`_asyncio.AsyncConnection` object.
+
+        The :class:`_asyncio.AsyncConnection` will procure a database
+        connection from the underlying connection pool when it is entered
+        as an async context manager::
+
+            async with async_engine.connect() as conn:
+                result = await conn.execute(select(user_table))
+
+        The :class:`_asyncio.AsyncConnection` may also be started outside of a
+        context manager by invoking its :meth:`_asyncio.AsyncConnection.start`
+        method.
+
+        """
+
+        return self._connection_cls(self)
+
+    async def raw_connection(self) -> PoolProxiedConnection:
+        """Return a "raw" DBAPI connection from the connection pool.
+
+        .. seealso::
+
+            :ref:`dbapi_connections`
+
+        """
+        return await greenlet_spawn(self.sync_engine.raw_connection)
+
+    @overload
+    def execution_options(
+        self,
+        *,
+        compiled_cache: Optional[CompiledCacheType] = ...,
+        logging_token: str = ...,
+        isolation_level: IsolationLevel = ...,
+        insertmanyvalues_page_size: int = ...,
+        schema_translate_map: Optional[SchemaTranslateMapType] = ...,
+        **opt: Any,
+    ) -> AsyncEngine: ...
+
+    @overload
+    def execution_options(self, **opt: Any) -> AsyncEngine: ...
+
+    def execution_options(self, **opt: Any) -> AsyncEngine:
+        """Return a new :class:`_asyncio.AsyncEngine` that will provide
+        :class:`_asyncio.AsyncConnection` objects with the given execution
+        options.
+
+        Proxied from :meth:`_engine.Engine.execution_options`.  See that
+        method for details.
+
+        """
+
+        return AsyncEngine(self.sync_engine.execution_options(**opt))
+
+    async def dispose(self, close: bool = True) -> None:
+        """Dispose of the connection pool used by this
+        :class:`_asyncio.AsyncEngine`.
+
+        :param close: if left at its default of ``True``, has the
+         effect of fully closing all **currently checked in**
+         database connections.  Connections that are still checked out
+         will **not** be closed, however they will no longer be associated
+         with this :class:`_engine.Engine`,
+         so when they are closed individually, eventually the
+         :class:`_pool.Pool` which they are associated with will
+         be garbage collected and they will be closed out fully, if
+         not already closed on checkin.
+
+         If set to ``False``, the previous connection pool is de-referenced,
+         and otherwise not touched in any way.
+
+        .. seealso::
+
+            :meth:`_engine.Engine.dispose`
+
+        """
+
+        await greenlet_spawn(self.sync_engine.dispose, close=close)
+
+    # START PROXY METHODS AsyncEngine
+
+    # code within this block is **programmatically,
+    # statically generated** by tools/generate_proxy_methods.py
+
+    def clear_compiled_cache(self) -> None:
+        r"""Clear the compiled cache associated with the dialect.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class on
+            behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        This applies **only** to the built-in cache that is established
+        via the :paramref:`_engine.create_engine.query_cache_size` parameter.
+        It will not impact any dictionary caches that were passed via the
+        :paramref:`.Connection.execution_options.compiled_cache` parameter.
+
+        .. versionadded:: 1.4
+
+
+        """  # noqa: E501
+
+        return self._proxied.clear_compiled_cache()
+
+    def update_execution_options(self, **opt: Any) -> None:
+        r"""Update the default execution_options dictionary
+        of this :class:`_engine.Engine`.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class on
+            behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        The given keys/values in \**opt are added to the
+        default execution options that will be used for
+        all connections.  The initial contents of this dictionary
+        can be sent via the ``execution_options`` parameter
+        to :func:`_sa.create_engine`.
+
+        .. seealso::
+
+            :meth:`_engine.Connection.execution_options`
+
+            :meth:`_engine.Engine.execution_options`
+
+
+        """  # noqa: E501
+
+        return self._proxied.update_execution_options(**opt)
+
+    def get_execution_options(self) -> _ExecuteOptions:
+        r"""Get the non-SQL options which will take effect during execution.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class on
+            behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        .. versionadded: 1.3
+
+        .. seealso::
+
+            :meth:`_engine.Engine.execution_options`
+
+        """  # noqa: E501
+
+        return self._proxied.get_execution_options()
+
+    @property
+    def url(self) -> URL:
+        r"""Proxy for the :attr:`_engine.Engine.url` attribute
+        on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        """  # noqa: E501
+
+        return self._proxied.url
+
+    @url.setter
+    def url(self, attr: URL) -> None:
+        self._proxied.url = attr
+
+    @property
+    def pool(self) -> Pool:
+        r"""Proxy for the :attr:`_engine.Engine.pool` attribute
+        on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        """  # noqa: E501
+
+        return self._proxied.pool
+
+    @pool.setter
+    def pool(self, attr: Pool) -> None:
+        self._proxied.pool = attr
+
+    @property
+    def dialect(self) -> Dialect:
+        r"""Proxy for the :attr:`_engine.Engine.dialect` attribute
+        on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        """  # noqa: E501
+
+        return self._proxied.dialect
+
+    @dialect.setter
+    def dialect(self, attr: Dialect) -> None:
+        self._proxied.dialect = attr
+
+    @property
+    def engine(self) -> Any:
+        r"""Returns this :class:`.Engine`.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class
+            on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        Used for legacy schemes that accept :class:`.Connection` /
+        :class:`.Engine` objects within the same variable.
+
+
+        """  # noqa: E501
+
+        return self._proxied.engine
+
+    @property
+    def name(self) -> Any:
+        r"""String name of the :class:`~sqlalchemy.engine.interfaces.Dialect`
+        in use by this :class:`Engine`.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class
+            on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+
+        """  # noqa: E501
+
+        return self._proxied.name
+
+    @property
+    def driver(self) -> Any:
+        r"""Driver name of the :class:`~sqlalchemy.engine.interfaces.Dialect`
+        in use by this :class:`Engine`.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class
+            on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+
+        """  # noqa: E501
+
+        return self._proxied.driver
+
+    @property
+    def echo(self) -> Any:
+        r"""When ``True``, enable log output for this element.
+
+        .. container:: class_bases
+
+            Proxied for the :class:`_engine.Engine` class
+            on behalf of the :class:`_asyncio.AsyncEngine` class.
+
+        This has the effect of setting the Python logging level for the namespace
+        of this element's class and object reference.  A value of boolean ``True``
+        indicates that the loglevel ``logging.INFO`` will be set for the logger,
+        whereas the string value ``debug`` will set the loglevel to
+        ``logging.DEBUG``.
+
+        """  # noqa: E501
+
+        return self._proxied.echo
+
+    @echo.setter
+    def echo(self, attr: Any) -> None:
+        self._proxied.echo = attr
+
+    # END PROXY METHODS AsyncEngine
+
+
+class AsyncTransaction(
+    ProxyComparable[Transaction], StartableContext["AsyncTransaction"]
+):
+    """An asyncio proxy for a :class:`_engine.Transaction`."""
+
+    __slots__ = ("connection", "sync_transaction", "nested")
+
+    sync_transaction: Optional[Transaction]
+    connection: AsyncConnection
+    nested: bool
+
+    def __init__(self, connection: AsyncConnection, nested: bool = False):
+        self.connection = connection
+        self.sync_transaction = None
+        self.nested = nested
+
+    @classmethod
+    def _regenerate_proxy_for_target(
+        cls, target: Transaction
+    ) -> AsyncTransaction:
+        sync_connection = target.connection
+        sync_transaction = target
+        nested = isinstance(target, NestedTransaction)
+
+        async_connection = AsyncConnection._retrieve_proxy_for_target(
+            sync_connection
+        )
+        assert async_connection is not None
+
+        obj = cls.__new__(cls)
+        obj.connection = async_connection
+        obj.sync_transaction = obj._assign_proxied(sync_transaction)
+        obj.nested = nested
+        return obj
+
+    @util.ro_non_memoized_property
+    def _proxied(self) -> Transaction:
+        if not self.sync_transaction:
+            self._raise_for_not_started()
+        return self.sync_transaction
+
+    @property
+    def is_valid(self) -> bool:
+        return self._proxied.is_valid
+
+    @property
+    def is_active(self) -> bool:
+        return self._proxied.is_active
+
+    async def close(self) -> None:
+        """Close this :class:`.AsyncTransaction`.
+
+        If this transaction is the base transaction in a begin/commit
+        nesting, the transaction will rollback().  Otherwise, the
+        method returns.
+
+        This is used to cancel a Transaction without affecting the scope of
+        an enclosing transaction.
+
+        """
+        await greenlet_spawn(self._proxied.close)
+
+    async def rollback(self) -> None:
+        """Roll back this :class:`.AsyncTransaction`."""
+        await greenlet_spawn(self._proxied.rollback)
+
+    async def commit(self) -> None:
+        """Commit this :class:`.AsyncTransaction`."""
+
+        await greenlet_spawn(self._proxied.commit)
+
+    async def start(self, is_ctxmanager: bool = False) -> AsyncTransaction:
+        """Start this :class:`_asyncio.AsyncTransaction` object's context
+        outside of using a Python ``with:`` block.
+
+        """
+
+        self.sync_transaction = self._assign_proxied(
+            await greenlet_spawn(
+                self.connection._proxied.begin_nested
+                if self.nested
+                else self.connection._proxied.begin
+            )
+        )
+        if is_ctxmanager:
+            self.sync_transaction.__enter__()
+        return self
+
+    async def __aexit__(self, type_: Any, value: Any, traceback: Any) -> None:
+        await greenlet_spawn(self._proxied.__exit__, type_, value, traceback)
+
+
+@overload
+def _get_sync_engine_or_connection(async_engine: AsyncEngine) -> Engine: ...
+
+
+@overload
+def _get_sync_engine_or_connection(
+    async_engine: AsyncConnection,
+) -> Connection: ...
+
+
+def _get_sync_engine_or_connection(
+    async_engine: Union[AsyncEngine, AsyncConnection]
+) -> Union[Engine, Connection]:
+    if isinstance(async_engine, AsyncConnection):
+        return async_engine._proxied
+
+    try:
+        return async_engine.sync_engine
+    except AttributeError as e:
+        raise exc.ArgumentError(
+            "AsyncEngine expected, got %r" % async_engine
+        ) from e
+
+
+@inspection._inspects(AsyncConnection)
+def _no_insp_for_async_conn_yet(
+    subject: AsyncConnection,  # noqa: U100
+) -> NoReturn:
+    raise exc.NoInspectionAvailable(
+        "Inspection on an AsyncConnection is currently not supported. "
+        "Please use ``run_sync`` to pass a callable where it's possible "
+        "to call ``inspect`` on the passed connection.",
+        code="xd3s",
+    )
+
+
+@inspection._inspects(AsyncEngine)
+def _no_insp_for_async_engine_xyet(
+    subject: AsyncEngine,  # noqa: U100
+) -> NoReturn:
+    raise exc.NoInspectionAvailable(
+        "Inspection on an AsyncEngine is currently not supported. "
+        "Please obtain a connection then use ``conn.run_sync`` to pass a "
+        "callable where it's possible to call ``inspect`` on the "
+        "passed connection.",
+        code="xd3s",
+    )