if(OBJECT_ID('tempdb..#tmp')>1)
drop table #tmp
create table #tmp (database_name nvarchar(100), table_name nvarchar(100), column_name nvarchar(100), ordinal_position int)
EXEC master..sp_MSForEachDB '
if(''?'' not in (''master'',''msdb'',''tempdb'',''model''))
begin
use [?]
insert into #tmp
select db_name(), table_name , column_name , ordinal_position from INFORMATION_SCHEMA.COLUMNS where TABLE_NAME = ''users''
end
'
go
select * from #tmp;
select *
from #tmp t1
inner join #tmp t2 on t1.column_name = t2.column_name
where t1.ordinal_position <> t2.ordinal_position
Tuesday, March 30, 2010
Wednesday, March 24, 2010
A simple way to loop true the time counter
startme:
print convert(nvarchar(100),GETDATE(),109);
waitfor delay '00:00:01';
if(GETDATE() > '2010-03-24 15:18:00.713')
begin
goto endme;
end
else
begin
goto startme;
end
endme:
print convert(nvarchar(100),GETDATE(),109);
waitfor delay '00:00:01';
if(GETDATE() > '2010-03-24 15:18:00.713')
begin
goto endme;
end
else
begin
goto startme;
end
endme:
Wednesday, March 17, 2010
Displaying Execution Plans
Check the query IO, TIME, Execution Plan, Plan Text while running a query
Displaying Execution Plans1
Displaying Execution Plans1
Select Top 100 Slow Queries
SELECT DISTINCT TOP 100
t.TEXT QueryName,
s.execution_count AS ExecutionCount,
s.max_elapsed_time AS MaxElapsedTime,
ISNULL(s.total_elapsed_time / 1000 / NULLIF(s.execution_count, 0), 0) AS AvgElapsedTime,
s.creation_time AS LogCreatedOn,
ISNULL(s.execution_count / 1000 / NULLIF(DATEDIFF(s, s.creation_time, GETDATE()), 0), 0) AS FrequencyPerSec
FROM sys.dm_exec_query_stats s
CROSS APPLY sys.dm_exec_sql_text( s.sql_handle ) t
WHERE s.execution_count > 1
ORDER BY AvgElapsedTime desc , s.max_elapsed_time DESC, ExecutionCount DESC;
GO
t.TEXT QueryName,
s.execution_count AS ExecutionCount,
s.max_elapsed_time AS MaxElapsedTime,
ISNULL(s.total_elapsed_time / 1000 / NULLIF(s.execution_count, 0), 0) AS AvgElapsedTime,
s.creation_time AS LogCreatedOn,
ISNULL(s.execution_count / 1000 / NULLIF(DATEDIFF(s, s.creation_time, GETDATE()), 0), 0) AS FrequencyPerSec
FROM sys.dm_exec_query_stats s
CROSS APPLY sys.dm_exec_sql_text( s.sql_handle ) t
WHERE s.execution_count > 1
ORDER BY AvgElapsedTime desc , s.max_elapsed_time DESC, ExecutionCount DESC;
GO
Tuesday, March 16, 2010
View SQL cached Plans and clean the execution cached plans
use Master
go
--clear cache
DBCC DROPCLEANBUFFERS
DBCC FREEPROCCACHE
go
USE master
GO
--view cached plans
SELECT UseCounts,RefCounts, Cacheobjtype, Objtype,
ISNULL(DB_NAME(dbid),'ResourceDB') AS DatabaseName, TEXT AS SQL
FROM sys.dm_exec_cached_plans
CROSS APPLY sys.dm_exec_sql_text(plan_handle)
ORDER BY dbid,usecounts DESC;
GO
go
--clear cache
DBCC DROPCLEANBUFFERS
DBCC FREEPROCCACHE
go
USE master
GO
--view cached plans
SELECT UseCounts,RefCounts, Cacheobjtype, Objtype,
ISNULL(DB_NAME(dbid),'ResourceDB') AS DatabaseName, TEXT AS SQL
FROM sys.dm_exec_cached_plans
CROSS APPLY sys.dm_exec_sql_text(plan_handle)
ORDER BY dbid,usecounts DESC;
GO
Friday, March 12, 2010
sp_kill
use master
go
if exists (select name from sysobjects where name = 'sp_kill' and type = 'p' )
drop proc sp_kill
go
create proc sp_kill
@dbname varchar(100) = null, -- When specified, kills all spids inside of the database
@loginame varchar(50) = null, -- When specified, kills all spids under the login name
@hostname varchar(50) = null -- When specified, kills all spids originating from the host machine
as
begin
set nocount on
select spid, db_name(dbid) as 'db_name', loginame, hostname into #tb1_sysprocesses from master.dbo.sysprocesses (nolock)
declare @total_logins int, @csr_spid varchar(100)
set @total_logins = ( select count(distinct spid) from #tb1_sysprocesses )
if @dbname is null
begin
if @loginame is null
begin
if @hostname is null
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
else
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where hostname = @hostname and loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
--------------------------------------------------
end
else
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where loginame = @loginame and loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
-----------------------
end
else
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where db_name = @dbname and loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
drop table #tb1_sysprocesses
end
go
if exists (select name from sysobjects where name = 'sp_kill' and type = 'p' )
drop proc sp_kill
go
create proc sp_kill
@dbname varchar(100) = null, -- When specified, kills all spids inside of the database
@loginame varchar(50) = null, -- When specified, kills all spids under the login name
@hostname varchar(50) = null -- When specified, kills all spids originating from the host machine
as
begin
set nocount on
select spid, db_name(dbid) as 'db_name', loginame, hostname into #tb1_sysprocesses from master.dbo.sysprocesses (nolock)
declare @total_logins int, @csr_spid varchar(100)
set @total_logins = ( select count(distinct spid) from #tb1_sysprocesses )
if @dbname is null
begin
if @loginame is null
begin
if @hostname is null
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
else
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where hostname = @hostname and loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
--------------------------------------------------
end
else
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where loginame = @loginame and loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
-----------------------
end
else
begin
if @total_logins > 0
begin
declare csr_spid cursor fast_forward for select distinct spid from #tb1_sysprocesses where db_name = @dbname and loginame <> 'sa' and spid <> @@spid
open csr_spid
fetch next from csr_spid into @csr_spid
while @@fetch_status = 0
begin
set nocount on
exec ('kill ' + @csr_spid)
fetch next from csr_spid into @csr_spid
end
close csr_spid
deallocate csr_spid
end
end
drop table #tb1_sysprocesses
end
Wednesday, February 24, 2010
Thursday, February 18, 2010
Is ISOLATION LEVEL READ UNCOMMITTED same as WITH (NOLOCK)
In one word, YES they are the same.
Transactions running at the READ UNCOMMITTED level do not issue shared locks to prevent other transactions from modifying data read by the current transaction. READ UNCOMMITTED transactions are also not blocked by exclusive locks that would prevent the current transaction from reading rows that have been modified but not committed by other transactions. When this option is set, it is possible to read uncommitted modifications, which are called dirty reads. Values in the data can be changed and rows can appear or disappear in the data set before the end of the transaction. This option has the same effect as setting NOLOCK on all tables in all SELECT statements in a transaction. This is the least restrictive of the isolation levels.
Check here for more detailed information
Also here is another document :
Read Committed Isolation Level
Transactions running at the READ UNCOMMITTED level do not issue shared locks to prevent other transactions from modifying data read by the current transaction. READ UNCOMMITTED transactions are also not blocked by exclusive locks that would prevent the current transaction from reading rows that have been modified but not committed by other transactions. When this option is set, it is possible to read uncommitted modifications, which are called dirty reads. Values in the data can be changed and rows can appear or disappear in the data set before the end of the transaction. This option has the same effect as setting NOLOCK on all tables in all SELECT statements in a transaction. This is the least restrictive of the isolation levels.
Check here for more detailed information
Also here is another document :
Read Committed Isolation Level
Find out all FK CONSTRAINT that exist on a table
declare @tableName varchar(200)
set @tableName = 'ssis_tasks'
select * from sys.foreign_keys k
inner join sys.tables t on t.[object_id] = k.referenced_object_id
where t.[name] = @tableName
SELECT * FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE where CONSTRAINT_NAME in
(
select k.name from sys.foreign_keys k
inner join sys.tables t on t.[object_id] = k.referenced_object_id
where t.[name] = @tableName
)
set @tableName = 'ssis_tasks'
select * from sys.foreign_keys k
inner join sys.tables t on t.[object_id] = k.referenced_object_id
where t.[name] = @tableName
SELECT * FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE where CONSTRAINT_NAME in
(
select k.name from sys.foreign_keys k
inner join sys.tables t on t.[object_id] = k.referenced_object_id
where t.[name] = @tableName
)
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