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Archive for the ‘DB Maintenance’ Category

T-SQL Script to find the size of every index in the database

Posted by Sudarshan Narasimhan on December 15, 2012


I wrote this query to find the size of all indexes in the database for one of my customers. Thought I’d share this script with everyone. Cheers.


CREATE PROCEDURE uspIndexSizeinDB
AS 
-- Author: Sudarshan (TheSQLDude.com)
-- Data Created: Dec 15, 2012
-- Description: Calculate the SQL Server index size for all indexes in the current database
  BEGIN 
    DECLARE  @IndexSize BIGINT, 
             @IndexID   INT,
             @IndexName nvarchar(200),
             @IndexType nvarchar(50),
             @ObjectID  INT
     
    SET @IndexSize = 0
    
    create table #tmpresults (ObjName nvarchar(100), IndexID int, IndexName nvarchar(200),[IndexSize(MB)] int, IndexType nvarchar(50))
    
    DECLARE curIndex CURSOR  FOR 
    SELECT sysind.object_id, sysind.index_id, sysind.name, sysind.type_desc 
    FROM sys.indexes sysind 
    join sys.sysobjects sysobj
    on sysind.object_id = sysobj.id
    where sysind.type>0 and sysobj.type not in ('S','IT')
    order by sysobj.id asc
   
    OPEN curIndex 
     
    FETCH NEXT FROM curIndex 
    INTO @ObjectID, @IndexID, @IndexName, @IndexType
     
    WHILE (@@FETCH_STATUS = 0) 
      BEGIN 
        SELECT @IndexSize = sum(avg_record_size_in_bytes * record_count) 
        FROM   sys.dm_db_index_physical_stats(DB_ID(),@ObjectID, @IndexID, NULL, 'detailED') 
         
        insert into #tmpresults (ObjName, IndexID, IndexName, [IndexSize(MB)], IndexType)
        SELECT TableName = OBJECT_NAME(@ObjectID), 
               IndexID = @IndexID, 
               IndexName = @IndexName,
               [IndexSize(MB)] = CONVERT(DECIMAL(16,1),(@IndexSize / (1024.0 * 1024))), IndexType = @IndexType
         
        FETCH NEXT FROM curIndex 
        INTO @ObjectID, @IndexID, @IndexName, @IndexType
      END 
    CLOSE curIndex 
    DEALLOCATE curIndex 
    
    select UPPER(ObjName) as ObjectName, IndexID, IndexName, IndexType, [IndexSize(MB)]  from #tmpresults order by [IndexSize(MB)] desc
  END 
GO

Posted in DB Maintenance, T-SQL | Tagged: , , , , , , | 2 Comments »

T-SQL Script for SQL Server Statistics Last Updated Time & Percent Rows modified

Posted by Sudarshan Narasimhan on August 4, 2011


I wrote a post on the same topic @ Amit’s Blog. I made some changes to the script to make it easier for DBA’s to read the output. I am re-posting this here for your reference. This can be quite handy if you are managing multiple SQL instances and you have lot of tables or have large databases where you only want to update statistics on some tables based on row modifications (data changes e.g. OLTP). You can always use DBCC SHOW_STATISTICS or SP_AUTOSTATS to find out the same information for a specific table, index or column stats.

select

schemas.name as table_schema,

tbls.name as Object_name,

i.id as Object_id,

i.name as index_name,

i.indid as index_id,

i.rowmodctr as modifiedRows,

(select max(rowcnt) from sysindexes i2 where i.id = i2.id and i2.indid < 2) as rowcnt,

convert(DECIMAL(18,8), convert(DECIMAL(18,8),i.rowmodctr) / convert(DECIMAL(18,8),(select max(rowcnt) from sysindexes i2 where i.id = i2.id and i2.indid < 2))) as ModifiedPercent,

stats_date( i.id, i.indid ) as lastStatsUpdateTime

from sysindexes i

inner join sysobjects tbls on i.id = tbls.id

inner join sysusers schemas on tbls.uid = schemas.uid

inner join information_schema.tables tl

on tbls.name = tl.table_name

and schemas.name = tl.table_schema

and tl.table_type=‘BASE TABLE’

where 0 < i.indid and i.indid < 255

and table_schema <> ‘sys’

and i.rowmodctr <> 0

and i.status not in (8388704,8388672)

and (select max(rowcnt) from sysindexes i2 where i.id = i2.id and i2.indid < 2) > 0

order by modifiedRows desc


Keep in mind that Rowmodctr values displayed in above output are not entirely reliable starting with SQL 2005 onwards. But, you can rely on last updated time to make a decision if the statistics need to be updated. Read here for more info on this.

 

 

You can use this script to generate the UPDATE STATISTICS command for each table in your table. I am using FULL SCAN by default, which you can of course modify to use specific SAMPLE. You have to un-comment the comments lines, to actually perform the update.

 

select identity(int,1,1) as rownum,table_name into table_count from information_schema.tables where table_type=‘base table’

declare @count int,@stmt varchar (255),@maxcount int,@tblname varchar(50)

set @count=1

select @maxcount=count(*) from table_count

while @count < @maxcount+1

begin

      select @tblname=table_name from table_count where rownum=@count

      set @stmt = ‘UPDATE STATISTICS ‘+ ‘[' +@tblname+ ']‘ + ‘ WITH FULLSCAN’

      print @stmt

      –PRINT (‘Updating statistics for table :’+@tblname)

      –EXEC(@stmt)

      –PRINT (‘Finished Updating statistics for table :’+@tblname)

      print

      set @count=@count+1

      set @stmt=

End

drop table table_count


Have fun with your database maintenanceSmile. As always stay tuned for more cool SQL stuff.

Posted in DB Maintenance | Tagged: , , , , , | 4 Comments »

 
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