选择索引

Question

我们假设我们有下表

 TABLE Something
      id
      description
      status

      PK (clustered index): id
      NC Index: id_status

1. NC索引没用吗？

2. 如果我们用索引状态替换NC索引id_status，并且查询在JOIN查询中引用status和id，这是否意味着PK_id和PK_status都将被使用？

Answer 1

不是一个真正的答案，只是帮助找到所有依赖于特定表的存储过程。这样，您可以检查SP

如何使用或不使用索引

SELECT OBJECT_NAME(sed.referencing_id) AS 'ReferEntity'
   ,o.type_desc AS 'Description'
   ,UPPER(sed.referenced_database_name) AS 'DB_Name'
   ,sed.referenced_schema_name AS 'Schema'
   ,sed.referenced_entity_name as 'EntityName'
   ,count(*) over (partition by OBJECT_NAME(sed.referencing_id)) as CountAll
FROM sys.sql_expression_dependencies AS sed 
INNER JOIN sys.objects AS o
    ON sed.referencing_id = o.object_id
WHERE o.type_desc = 'SQL_STORED_PROCEDURE'
    and sed.referenced_entity_name = 'MyTable'
order by 1