# PoolKey


A unique identifier for a connection pool instance.


`PoolKey: TypeAlias = tuple[BackendName, str, int]`


The triple `(backend, host, port)` distinguishes pools that target different servers. Two calls to [get_connection()](get_connection.md#gdtest_complete_docstrings.get_connection) with the same pool key reuse the same underlying pool.


## See Also

[BackendName](BackendName.md#gdtest_complete_docstrings.BackendName)  

[get_connection()](get_connection.md#gdtest_complete_docstrings.get_connection)