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The indexing schema plays a fundamental role in performance tuning, and tools such as the Index Tuning Wizard that can suggest efficient schemas on the grounds of a database usage. Once the indexing schema has been completed, you should document it in order to know which tables have primary keys, which have clustered keys, which and how many are the non clustered indexes of a certain table. You can get this metadata through SQL Server Information Schema's views, that are based on the following system tables: sysobjects, syscolumns, sysreferences, spt_values, and sysindexes.
Unfortunately these tables don't provide all the necessary values, but the Books Online documentation lets to derive the meaning of all the fields in these system tables. The following sp_help_db_indexes stored procedure, placed inside the master database, lets to view all the indexes of each table for the current database, with the respective name, type and fields that make it up: |
Click here to copy the following block |
CREATE procedure sp_help_db_indexes AS
declare @empty varchar(1) select @empty = ''
declare @IgnoreDuplicateKeys varchar(35), @Unique varchar(35), @IgnoreDuplicateRows varchar(35), @Clustered varchar(35), @Hypotethical varchar(35), @Statistics varchar(35), @PrimaryKey varchar(35), @UniqueKey varchar(35), @AutoCreate varchar(35), @StatsNoRecompute varchar(35)
select @IgnoreDuplicateKeys = name from master.dbo.spt_values where type = 'I' and number = 1 select @Unique = name from master.dbo.spt_values where type = 'I' and number = 2 select @IgnoreDuplicateRows = name from master.dbo.spt_values where type = 'I' and number = 4 select @Clustered = name from master.dbo.spt_values where type = 'I' and number = 16 select @Hypotethical = name from master.dbo.spt_values where type = 'I' and number = 32 select @Statistics = name from master.dbo.spt_values where type = 'I' and number = 64 select @PrimaryKey = name from master.dbo.spt_values where type = 'I' and number = 2048 select @UniqueKey = name from master.dbo.spt_values where type = 'I' and number = 4096 select @AutoCreate = name from master.dbo.spt_values where type = 'I' and number = 8388608 select @StatsNoRecompute = name from master.dbo.spt_values where type = 'I' and number = 16777216 select o.name, i.name, 'index description' = convert(varchar(210), case when (i.status & 16)<>0 then @Clustered else 'non'+@Clustered end + case when (i.status & 1)<>0 then ', '+@IgnoreDuplicateKeys else @empty end + case when (i.status & 2)<>0 then ', '+@Unique else @empty end + case when (i.status & 4)<>0 then ', '+@IgnoreDuplicateRows else @empty end + case when (i.status & 64)<>0 then ', '+@Statistics else case when (i.status & 32)<>0 then ', '+@Hypotethical else @empty end end + case when (i.status & 2048)<>0 then ', '+@PrimaryKey else @empty end + case when (i.status & 4096)<>0 then ', '+@UniqueKey else @empty end + case when (i.status & 8388608)<>0 then ', '+@AutoCreate else @empty end + case when (i.status & 16777216)<>0 then ', '+@StatsNoRecompute else @empty end), 'index column 1' = index_col(o.name,indid, 1), 'index column 2' = index_col(o.name,indid, 2), 'index column 3' = index_col(o.name,indid, 3) from sysindexes i, sysobjects o where i.id = o.id and indid > 0 and indid < 255 -all the clustered (=1), non clusterd (>1 and <251), and text or image (=255) and o.type = 'U' -user table and (i.status & 64) = 0 -index with duplicates and (i.status & 8388608) = 0 -auto created index and (i.status & 16777216)= 0 order by o.name |
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Submitted By :
Nayan Patel
(Member Since : 5/26/2004 12:23:06 PM)
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Job Description :
He is the moderator of this site and currently working as an independent consultant. He works with VB.net/ASP.net, SQL Server and other MS technologies. He is MCSD.net, MCDBA and MCSE. In his free time he likes to watch funny movies and doing oil painting. |
View all (893) submissions by this author
(Birth Date : 7/14/1981 ) |
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