詳解sqlserver查詢表索引
SELECT 索引名稱=a.name
,表名=c.name
,索引字段名=d.name
,索引字段位置=d.colid
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 --查所有用戶表 AND c.name='message' --查指定表 ORDER BY c.name,a.name,d.name
需創(chuàng)建索引 例如:
根據(jù)某列判斷是否有重復(fù)記錄,如果該列為非主鍵,則創(chuàng)建索引
根據(jù)經(jīng)常查詢的列,創(chuàng)建索引
無須創(chuàng)建索引
字段內(nèi)容大部分一樣,例如:男,女
不要給所有的列都創(chuàng)建索引,這樣在創(chuàng)建新記錄時,增加維護開銷時間。
Oracle 查詢用戶表索引
select index_name,index_type,table_name from user_indexes where table_name='表名'
SqlServer查詢一個表上的索引
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是你要查詢的表
以上內(nèi)容就是本文全部所述,希望大家喜歡。
版權(quán)聲明:本站文章來源標注為YINGSOO的內(nèi)容版權(quán)均為本站所有,歡迎引用、轉(zhuǎn)載,請保持原文完整并注明來源及原文鏈接。禁止復(fù)制或仿造本網(wǎng)站,禁止在非maisonbaluchon.cn所屬的服務(wù)器上建立鏡像,否則將依法追究法律責任。本站部分內(nèi)容來源于網(wǎng)友推薦、互聯(lián)網(wǎng)收集整理而來,僅供學(xué)習參考,不代表本站立場,如有內(nèi)容涉嫌侵權(quán),請聯(lián)系alex-e#qq.com處理。
關(guān)注官方微信