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63 lines
1.7 KiB
ReStructuredText
63 lines
1.7 KiB
ReStructuredText
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`psycopg2.pool` -- Connections pooling
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======================================
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.. sectionauthor:: Daniele Varrazzo <daniele.varrazzo@gmail.com>
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.. index::
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pair: Connection; Pooling
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.. module:: psycopg2.pool
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Creating new PostgreSQL connections can be an expensive operation. This
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module offers a few pure Python classes implementing simple connection pooling
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directly into the client application.
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.. class:: AbstractConnectionPool(minconn, maxconn, \*args, \*\*kwargs)
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Base class implementing generic key-based pooling code.
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New *minconn* connections are created automatically. The pool will support
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a maximum of about *maxconn* connections. *\*args* and *\*\*kwargs* are
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passed to the :func:`~psycopg2.connect` function.
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The following methods are expected to be implemented by subclasses:
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.. method:: getconn(key=None)
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Get a free connection and assign it to *key* if not ``None``.
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.. method:: putconn(conn, key=None)
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Put away a connection.
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.. method:: closeall
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Close all the connections handled by the pool.
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Notice that all the connections are closed, including ones
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eventually in use by the application.
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The following classes are :class:`AbstractConnectionPool` subclasses ready to
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be used.
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.. autoclass:: SimpleConnectionPool
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.. note:: This pool class is useful only for single-threaded applications.
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.. index:: Multithread; Connection pooling
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.. autoclass:: ThreadedConnectionPool
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.. note:: This pool class can be safely used in multi-threaded applications.
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.. autoclass:: PersistentConnectionPool
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.. note::
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This pool class is mostly designed to interact with Zope and probably
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not useful in generic applications.
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