索引的重建与查询

Posted 2020-09-26

sp_helpindex ‘tablename‘
----------------------------------------------------------------------------------
--查询当前数据库的所有索引值
SELECT database_id,object_id,index_id,object_name(object_id) as table_name,
avg_fragmentation_in_percent,fragment_count,
avg_fragment_size_in_pages 
FROM sys.dm_db_index_physical_stats(DB_ID(),NULL,NULL,NULL,‘DETAILED‘);

----------------------------------------------------------------------------
--查询所有数据库的所有索引值
SELECT I.database_id,D.NAME,I.object_id,I.index_id,object_name(object_id) as table_name,
I.avg_fragmentation_in_percent,I.fragment_count,
I.avg_fragment_size_in_pages 
FROM sys.dm_db_index_physical_stats(null,NULL,NULL,NULL,‘DETAILED‘) I
left join sys.databases D on D.DATABASE_ID=I.DATABASE_ID;

-------------------------------------------------------------------------
--显示指定的表的数据和索引的碎片信息
use datbase  --数据库
declare @table_id int
set @table_id=object_id(‘tablename‘)  --所要查询索引所在表
dbcc showcontig(@table_id)
----------------------------------------------------------------------
/*
DBCC SHOWCONTIG 正在扫描 ‘tablename‘ 表...
表: ‘tablename‘ (1149299204)；索引 ID: 1，数据库 ID: 18
已执行 TABLE 级别的扫描。
- 扫描页数................................: 327
- 扫描区数..............................: 45
- 区切换次数..............................: 291
- 每个区的平均页数........................: 7.3
- 扫描密度 [最佳计数:实际计数].......: 14.04% [41:292]
- 逻辑扫描碎片 ..................: 85.32%  --重点查询区域
- 区扫描碎片 ..................: 31.11%    --重点查询区域
- 每页的平均可用字节数.....................: 3435.6
- 平均页密度(满).....................: 57.55%
DBCC 执行完毕。如果 DBCC 输出了错误信息，请与系统管理员联系。
*/
-----------------------------------------------------------------------------------

--重建索引，提高查询效率
dbcc dbreindex(tablename,‘‘,0)

-----------------------------------------------------------------------------------
use database
GO
-- 查询一个表中的索引及索引列

SELECT  indexname = a.name , tablename = c. name , indexcolumns = d .name , a .indid
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 = ‘DatabaseLog‘ --查指定表
ORDER BY c. name ,a.name ,d.name


---------------------------------------------------------------------------------------------
SELECT
 tab.name AS [表名],
 idx.name AS [索引名称],
 col.name AS [列名]
FROM
 sys.indexes idx
 JOIN sys.index_columns idxCol 
 ON (idx.object_id = idxCol.object_id 
 AND idx.index_id = idxCol.index_id 
 )
 JOIN sys.tables tab
 ON (idx.object_id = tab.object_id)
 JOIN sys.columns col
 ON (idx.object_id = col.object_id
 AND idxCol.column_id = col.column_id);