httk.store.backend.duckdb.engine
================================

.. py:module:: httk.store.backend.duckdb.engine

.. autoapi-nested-parse::

   DuckDB database construction for :class:`~httk.store.backend.sql.engine.Backend`.



Functions
---------

.. autoapisummary::

   httk.store.backend.duckdb.engine.database


Module Contents
---------------

.. py:function:: database(cls, path = None, *, memory_limit = None, read_only = False)

   Build a DuckDB-backed backend stored in ``path``, or in memory when ``path`` is None.

   :param cls: The backend class to instantiate.
   :param path: The database file path, or ``None`` for an in-memory database.
   :param memory_limit: An optional DuckDB ``memory_limit`` setting such as
       ``"1GB"``. DuckDB's own default allows every instance up to about 80% of
       system RAM, which multiplies dangerously across parallel test or ingest
       processes; when this parameter is ``None`` the ``HTTK_DUCKDB_MEMORY_LIMIT``
       environment variable (if set) supplies the cap instead, so process trees
       can be memory-guarded wholesale.
   :param read_only: Open the file in DuckDB ``READ_ONLY`` access mode. A read-only
       database takes no write lock, so several processes (and this one) may open the
       same file concurrently for reading; write operations on the resulting backend
       will fail. Ignored for the in-memory database.
   :return: The configured backend wrapper.
   :raises ImportError: If the ``duckdb_engine`` SQLAlchemy dialect is not installed;
       install the ``httk-store[duckdb]`` extra to use it.