Monday, January 23, 2006

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sp_who2 to sp_whoDB

As a DBA, there might not be a date that you didn’t use this tool. It is a wonderful tool and you will also be asked on attending interviews. But, have you wondered of adding parameters to this procedure and use it only to show only information on specific database? Well, a small modification of this stored procedure helped me in doing this, I am sure it will help you too. There isn’t much modification to it but the idea of only seeing the connection to database that you want is in my opinion is good one. You can create this sp in master database and use the same as you use sp_who2. The only difference is you can pass the database name as a parameter.



CREATE PROCEDURE sp_whoDB
@dbname sysname = null,
@loginame sysname = NULL
as

set nocount on
declare
@retcode int
declare @dbid int

select @dbid = dbid from sysdatabases where name = @dbname

declare
@sidlow varbinary(85)
,@sidhigh varbinary(85)
,@sid1 varbinary(85)
,@spidlow int
,@spidhigh int

declare
@charMaxLenLoginName varchar(6)
,@charMaxLenDBName varchar(6)
,@charMaxLenCPUTime varchar(10)
,@charMaxLenDiskIO varchar(10)
,@charMaxLenHostName varchar(10)
,@charMaxLenProgramName varchar(10)
,@charMaxLenLastBatch varchar(10)
,@charMaxLenCommand varchar(10)

declare
@charsidlow varchar(85)
,@charsidhigh varchar(85)
,@charspidlow varchar(11)
,@charspidhigh varchar(11)
--------
select
@retcode = 0 -- 0=good ,1=bad.

--------defaults
select @sidlow = convert(varbinary(85), (replicate(char(0), 85)))
select @sidhigh = convert(varbinary(85), (replicate(char(1), 85)))

select
@spidlow = 0
,@spidhigh = 32767

--------------------------------------------------------------
IF (@loginame IS NULL) --Simple default to all LoginNames.
GOTO LABEL_17PARM1EDITED
--------
-- select @sid1 = suser_sid(@loginame)
select @sid1 = null
if exists(select * from master.dbo.syslogins where loginname = @loginame)
select @sid1 = sid from master.dbo.syslogins where loginname = @loginame

IF (@sid1 IS NOT NULL) --Parm is a recognized login name.
begin
select @sidlow = suser_sid(@loginame)
,@sidhigh = suser_sid(@loginame)
GOTO LABEL_17PARM1EDITED
end
--------
IF (lower(@loginame) IN ('active')) --Special action, not sleeping.
begin
select @loginame = lower(@loginame)
GOTO LABEL_17PARM1EDITED
end
--------
IF (patindex ('%[^0-9]%' , isnull(@loginame,'z')) = 0) --Is a number.
begin
select
@spidlow = convert(int, @loginame)
,@spidhigh = convert(int, @loginame)
GOTO LABEL_17PARM1EDITED
end

--------

RaisError(15007,-1,-1,@loginame)
select @retcode = 1
GOTO LABEL_86RETURN

LABEL_17PARM1EDITED:
-------------------- Capture consistent sysprocesses. -------------------
SELECT

spid
,status
,sid
,hostname
,program_name
,cmd
,cpu
,physical_io
,blocked
,dbid
,convert(sysname, rtrim(loginame))
as loginname
,spid as 'spid_sort'

, substring( convert(varchar,last_batch,111) ,6 ,5 ) + ' '
+ substring( convert(varchar,last_batch,113) ,13 ,8 )
as 'last_batch_char'

INTO #tb1_sysprocesses
from master.dbo.sysprocesses (nolock)
where (dbid = @dbId or @dbName is null) and spid > 12




--------Screen out any rows?

IF (@loginame IN ('active'))
DELETE #tb1_sysprocesses
where lower(status) = 'sleeping'
and upper(cmd) IN (
'AWAITING COMMAND'
,'MIRROR HANDLER'
,'LAZY WRITER'
,'CHECKPOINT SLEEP'
,'RA MANAGER'
)

and blocked = 0



--------Prepare to dynamically optimize column widths.


Select
@charsidlow = convert(varchar(85),@sidlow)
,@charsidhigh = convert(varchar(85),@sidhigh)
,@charspidlow = convert(varchar,@spidlow)
,@charspidhigh = convert(varchar,@spidhigh)



SELECT
@charMaxLenLoginName =
convert( varchar
,isnull( max( datalength(loginname)) ,5)
)

,@charMaxLenDBName =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),db_name(dbid))))) ,6)
)

,@charMaxLenCPUTime =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),cpu)))) ,7)
)

,@charMaxLenDiskIO =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),physical_io)))) ,6)
)

,@charMaxLenCommand =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),cmd)))) ,7)
)

,@charMaxLenHostName =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),hostname)))) ,8)
)

,@charMaxLenProgramName =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),program_name)))) ,11)
)

,@charMaxLenLastBatch =
convert( varchar
,isnull( max( datalength( rtrim(convert(varchar(128),last_batch_char)))) ,9)
)
from
#tb1_sysprocesses
where
-- sid >= @sidlow
-- and sid <= @sidhigh
-- and
spid >= @spidlow
and spid <= @spidhigh



--------Output the report.


EXECUTE(
'
SET nocount off

SELECT
SPID = convert(char(5),spid)

,Status =
CASE lower(status)
When ''sleeping'' Then lower(status)
Else upper(status)
END

,Login = substring(loginname,1,' + @charMaxLenLoginName + ')

,HostName =
CASE hostname
When Null Then '' .''
When '' '' Then '' .''
Else substring(hostname,1,' + @charMaxLenHostName + ')
END

,BlkBy =
CASE isnull(convert(char(5),blocked),''0'')
When ''0'' Then '' .''
Else isnull(convert(char(5),blocked),''0'')
END

,DBName = substring(case when dbid = 0 then null when dbid <> 0 then db_name(dbid) end,1,' + @charMaxLenDBName + ')
,Command = substring(cmd,1,' + @charMaxLenCommand + ')

,CPUTime = substring(convert(varchar,cpu),1,' + @charMaxLenCPUTime + ')
,DiskIO = substring(convert(varchar,physical_io),1,' + @charMaxLenDiskIO + ')

,LastBatch = substring(last_batch_char,1,' + @charMaxLenLastBatch + ')

,ProgramName = substring(program_name,1,' + @charMaxLenProgramName + ')
,SPID = convert(char(5),spid) --Handy extra for right-scrolling users.
from
#tb1_sysprocesses --Usually DB qualification is needed in exec().
where
spid >= ' + @charspidlow + '
and spid <= ' + @charspidhigh + '

order by spid_sort

SET nocount on
'
)
/*****AKUNDONE: removed from where-clause in above EXEC sqlstr
sid >= ' + @charsidlow + '
and sid <= ' + @charsidhigh + '
and
**************/
LABEL_86RETURN:

if (object_id('tempdb..#tb1_sysprocesses') is not null)
drop table #tb1_sysprocesses

return @retcode -- sp_who2

Finding duplicate indexes

It is always a good idea to check your databases for duplicate indexes. Duplicate indexes don’t do any good. The first question you ask yourself is why is it there in the first place? It might be the case it is not there but this is something that I have encountered in various occasions and it doesn’t harm to check if there are any duplicate indexes in your database. The next step is how to check; here I have tried to do this. The following script will help you find duplicate indexes on up to 5 columns. If you have got indexes on more that five columns, you can extend it to as many column as you want.

SELECT l1.tablename,
l1.indexname,
l2.indexname AS duplicateIndex
FROM
(SELECT tbl.[name] AS TableName,
idx.[name] AS IndexName,
INDEX_COL( tbl.[name], idx.indid, 1 ) AS col1,
INDEX_COL( tbl.[name], idx.indid, 2 ) AS col2,
INDEX_COL( tbl.[name], idx.indid, 3 ) AS col3,
INDEX_COL( tbl.[name], idx.indid, 4 ) AS col4,
INDEX_COL( tbl.[name], idx.indid, 5 ) AS col5
FROM SYSINDEXES idx
INNER JOIN SYSOBJECTS tbl ON idx.[id] = tbl.[id]
WHERE indid > 0
AND INDEXPROPERTY( tbl.[id], idx.[name], 'IsStatistics') = 0 ) l1
JOIN
(SELECT tbl.[name] AS TableName,
idx.[name] AS IndexName,
INDEX_COL( tbl.[name], idx.indid, 1 ) AS col1,
INDEX_COL( tbl.[name], idx.indid, 2 ) AS col2,
INDEX_COL( tbl.[name], idx.indid, 3 ) AS col3,
INDEX_COL( tbl.[name], idx.indid, 4 ) AS col4,
INDEX_COL( tbl.[name], idx.indid, 5 ) AS col5
FROM SYSINDEXES idx
INNER JOIN SYSOBJECTS tbl ON idx.[id] = tbl.[id]
WHERE indid > 0
AND INDEXPROPERTY( tbl.[id], idx.[name], 'IsStatistics') = 0) l2
ON l1.tablename = l2.tablename
AND l1.indexname <> l2.indexname
AND l1.col1 = l2.col1
AND COALESCE(l1.col2,'') = COALESCE(l2.col2,'')
AND COALESCE(l1.col3,'') = COALESCE(l2.col3,'')
AND COALESCE(l1.col4,'') = COALESCE(l2.col4,'')
AND COALESCE(l1.col5,'') = COALESCE(l2.col5,'')



Once you find your duplicate indexes, remove non-clustered indexes if one of the indexes is clustered.