Exists 与 In 的物化视图性能

物化视图是一种数据库技术，通过事先计算和存储查询结果，提高查询性能和数据访问效率。在物化视图中，存在两种常见的操作：Exists和In。本文将探讨这两种操作在物化视图中的性能表现，并提供相应的案例代码进行演示。

sql
-- 创建物化视图
CREATE MATERIALIZED VIEW mv_exists AS
SELECT column1, column2
FROM table1
WHERE EXISTS (
    SELECT 1
    FROM table2
    WHERE table1.column1 = table2.column1
);
-- 查询物化视图
SELECT column1, column2
FROM mv_exists
WHERE column1 = 'value';

sql
-- 创建物化视图
CREATE MATERIALIZED VIEW mv_in AS
SELECT column1, column2
FROM table1
WHERE column1 IN (
    SELECT column1
    FROM table2
);
-- 查询物化视图
SELECT column1, column2
FROM mv_in
WHERE column1 = 'value';

sql
-- 创建物化视图
CREATE MATERIALIZED VIEW mv_exists AS
SELECT product_id, product_name
FROM Product
WHERE EXISTS (
    SELECT 1
    FROM Order
    WHERE Product.product_id = Order.product_id
    AND Order.shipped = false
);
-- 查询物化视图
SELECT product_id, product_name
FROM mv_exists;

sql
-- 创建物化视图
CREATE MATERIALIZED VIEW mv_in AS
SELECT product_id, product_name
FROM Product
WHERE product_id IN (
    SELECT product_id
    FROM Order
    WHERE shipped = false
);
-- 查询物化视图
SELECT product_id, product_name
FROM mv_in;