使用临时表来优化视图和UDF的性能。 将视图中使用的UDF的结果存储在临时表中,然后在查询视图时直接引用该临时表,以避免重复计算UDF的结果。
代码示例:
创建一个UDF:
CREATE FUNCTION get_customer_name(customer_id int) RETURNS text AS $$ SELECT name FROM customers WHERE id = customer_id; $$ LANGUAGE SQL;
创建一个视图:
CREATE VIEW orders_view AS SELECT order_id, order_date, get_customer_name(customer_id) as customer_name FROM orders;
使用临时表来优化视图和UDF的性能:
CREATE TEMP TABLE temp_orders AS SELECT order_id, order_date, customer_id, get_customer_name(customer_id) as customer_name FROM orders;
CREATE VIEW orders_view AS SELECT order_id, order_date, customer_name FROM temp_orders;