2022年6月23日
Logical Processing Order of the SELECT statement
摘要： What's the execute order of the different parts of a SQL select statement? 问题 What's the execute order of the different parts of a SQL select statemen 阅读全文
posted @ 2022-06-23 13:40 ChuckLu 阅读(17) 评论(0) 推荐(0)
Multiple Indexes vs Multi-Column Indexes
摘要： Multiple Indexes vs Multi-Column Indexes 问题 What is the difference between creating one index across multiple columns versus creating multiple indexes 阅读全文
posted @ 2022-06-23 13:17 ChuckLu 阅读(34) 评论(0) 推荐(0)
Partitioned SUM and COUNT sql online,在线示例，online example, partition by
摘要： 最新的理解 4张表 as cte1， abcd 3张表 as cte2, aef 把cet1和cte2进行join的时候，partition需要调整， cte1里面的partition by需要加上ef的字段 cte2里面的partition by需要加上bcd的字段 核心，这里做除法的时候 cou 阅读全文
posted @ 2022-06-23 12:24 ChuckLu 阅读(12) 评论(0) 推荐(0)