SELECT 索引名称=a.name
,表名=c.name
,索引字段名=d.name
,索引字段位置=d.colid
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FROM sysindexes a JOIN sysindexkeys b ON a.id=b.id AND a.indid=b.indid JOIN sysobjects c ON b.id=c.id JOIN syscolumns d ON b.id=d.id AND b.colid=d.colid WHERE a.indid NOT IN (0,255) -- and c.xtype='U' and c.status>0 --查所有用户表 AND c. name = 'message' --查指定表 ORDER BY c. name ,a. name ,d. name |
需创建索引 例如:
根据某列判断是否有重复记录,如果该列为非主键,则创建索引
根据经常查询的列,创建索引
无须创建索引
字段内容大部分一样,例如:男,女
不要给所有的列都创建索引,这样在创建新记录时,增加维护开销时间。
Oracle 查询用户表索引
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select index_name,index_type,table_name from user_indexes where table_name= '表名' |
SqlServer查询一个表上的索引
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SELECT TableId=O.[object_id], TableName=O. Name , IndexId= ISNULL (KC.[object_id],IDX.index_id), IndexName=IDX. Name , IndexType= ISNULL (KC.type_desc, 'Index' ), Index_Column_id=IDXC.index_column_id, ColumnID=C.Column_id, ColumnName=C. Name , Sort= CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id, 'IsDescending' ) WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END , PrimaryKey= CASE WHEN IDX.is_primary_key=1 THEN N '√' ELSE N '' END , [UQIQUE]= CASE WHEN IDX.is_unique=1 THEN N '√' ELSE N '' END , Ignore_dup_key= CASE WHEN IDX.ignore_dup_key=1 THEN N '√' ELSE N '' END , Disabled= CASE WHEN IDX.is_disabled=1 THEN N '√' ELSE N '' END , Fill_factor=IDX.fill_factor, Padded= CASE WHEN IDX.is_padded=1 THEN N '√' ELSE N '' END FROM sys.indexes IDX INNER JOIN sys.index_columns IDXC ON IDX.[object_id]=IDXC.[object_id] AND IDX.index_id=IDXC.index_id LEFT JOIN sys.key_constraints KC ON IDX.[object_id]=KC.[parent_object_id] AND IDX.index_id=KC.unique_index_id INNER JOIN sys.objects O ON O.[object_id]=IDX.[object_id] INNER JOIN sys.columns C ON O.[object_id]=C.[object_id] AND O.type= 'U' AND O.is_ms_shipped=0 AND IDXC.Column_id=C.Column_id where O. name = 'cz201' --cz201是你要查询的表 |
以上内容就是本文全部所述,希望大家喜欢。