Question

我们正在从django后端和lambda连接到Postgresql（RDS）服务器，有时django后端查询超时，我运行以下查询来查看锁：

                SELECT
                    pg_stat_activity.client_addr,
                    pg_stat_activity.query
                FROM pg_class
                JOIN
                    pg_locks ON pg_locks.relation = pg_class.oid
                JOIN
                    pg_stat_activity ON pg_locks.pid =
                    pg_stat_activity.pid
                WHERE
                    pg_locks.granted='t' AND
                    pg_class.relname='accounts_user'

这为我提供了从lambda执行的30行简单选择查询，如下所示：

SELECT first_name, picture, username FROM accounts_user WHERE id = $1

此查询为什么拥有锁？我应该担心吗？

我正在使用pg8000库从Lambda连接

    with pgsql.cursor() as cursor:
        cursor.execute(
            """
            SELECT first_name, picture, username
            FROM accounts_user
            WHERE id = %s
            """,
            (author_user_id,),
        )
        row = cursor.fetchone()
    # use the row ..

我在Github上发布了一个问题，可能是因为我使用的库不正确。 https://github.com/tlocke/pg8000/issues/16

Answer 1

您也可以尝试重用数据库连接，请参见https://docs.djangoproject.com/en/2.2/ref/settings/#conn-max-age

    DATABASES = {
        'default': {
            ...
            'CONN_MAX_AGE': 600,             # reuse database connection
        }
    }

pg_locks表有很多简单的选择语句

1 个答案: