SQL Server-聚焦IN VS EXISTS VS JOIN性能分析
N VS EXISTS VS JOIN性能分析我们继续创建测试表，如下
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CREATE SCHEMA
CREATE TABLE t_outer (
id INT NOT NULL PRIMARY KEY,
val1 INT NOT NULL,
val2 INT NOT NULL
)
CREATE TABLE t_inner (
id INT NOT NULL PRIMARY KEY,
val1 INT NOT NULL,
val2 INT NOT NULL
)
CREATE TABLE t_smallinner (
id INT NOT NULL PRIMARY KEY,
val1 INT NOT NULL,
val2 INT NOT NULL
)
GO
CREATE INDEX ix_outer_val1 ON .t_outer (val1)
CREATE INDEX ix_inner_val1 ON .t_inner (val1)
CREATE INDEX ix_smallinner_val1 ON .t_smallinner (val1)
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创建三个表即t_outer、t_inner、t_smaler同时将三个表中的列val1创建索引而对t_smaller表中的val2未创建索引，下面我们开始插入测试数据
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USE TSQL2012
GO
DECLARE @num INT
SET @num = 1WHILE @num
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