Pages

Search This Blog

Showing posts with label stored procedure. Show all posts
Showing posts with label stored procedure. Show all posts

Saturday, August 25, 2012

[T-SQL] Database backup procedure - advanced

I have got this script from one of the blogs:

if exists (select * from sysobjects where id = object_id(N'[dbo].[spBackupAllDatabases]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[spBackupAllDatabases]
go

Create Procedure spBackupAllDatabases
@Path varchar(128) ,
@Type varchar(4) -- Full / Log
as
/*
Backup file format
_Full_yyyymmdd_hhmmss.bak
_Log_yyyymmdd_hhmmss.bak

exec spBackupAllDatabases 'c:\SQLBackups\', 'Full'
*/
/*
drop table DatabaseBackup

Create table DatabaseBackup
(
Name varchar(128) primary key nonclustered ,
BackupFlagFull varchar(1) not null check (BackupFlagFull in ('Y','N')) ,
BackupFlagLog varchar(1) not null check (BackupFlagLog in ('Y','N')) ,
RetentionPeriodFull datetime not null ,
RetentionPeriodLog datetime not null
)
*/
set nocount on
declare @sql varchar(1000)

-- Get all database names
create table #DBName
(
ID int identity (1,1) ,
Name varchar(128) not null ,
RetentionPeriod datetime null
)

insert #DBName
(Name)
select name
from master..sysdatabases

-- Include any new databases in the backup
insert DatabaseBackup
(
Name ,
BackupFlagFull ,
BackupFlagLog ,
RetentionPeriodFull ,
RetentionPeriodLog
)
select #DBName.Name ,
'Y' ,
'N' ,
'7 jan 1900' , -- default one week
'1 jan 1900'
from #DBName
left outer join DatabaseBackup
on DatabaseBackup.Name = #DBName.Name
where DatabaseBackup.Name is null
and lower(#DBName.Name) <> 'tempdb'

-- Remove any non-existant databases
delete DatabaseBackup
where not exists
(
select *
from #DBName
where #DBName.Name = DatabaseBackup.Name
)

delete #DBName

create table #ExistingBackups
(
Name varchar(128) ,
ID int identity (1,1)
)

-- loop through databases
declare @Name varchar(128) ,
@RetentionPeriod datetime ,
@LastBackupToKeep varchar(8) ,
@ID int ,
@MaxID int

insert #DBName
(Name, RetentionPeriod)
select Name, case when @Type = 'Full' then RetentionPeriodFull else RetentionPeriodLog end
from DatabaseBackup
where (@Type = 'Full' and BackupFlagFull = 'Y')
or (@Type = 'Log' and BackupFlagLog = 'Y')

select @MaxID = max(ID) ,
@ID = 0
from #DBName

while @ID < @MaxID begin -- get next database to backup select @ID = min(ID) from #DBName where ID > @ID

select @Name = Name ,
@RetentionPeriod = RetentionPeriod
from #DBName
where ID = @ID

-- Delete old backups
delete #ExistingBackups
select @sql = 'dir /B ' + @Path
select @sql = @sql + @Name + '_' + @Type + '*.*'

insert #ExistingBackups exec master..xp_cmdshell @sql

if exists (select * from #ExistingBackups where Name like '%File Not Found%')
delete #ExistingBackups

select @LastBackupToKeep = convert(varchar(8),getdate() - @RetentionPeriod,112)
delete #ExistingBackups where Name > @Name + '_' + @Type + '_' + @LastBackupToKeep

declare @eID int ,
@eMaxID int ,
@eName varchar(128)

-- loop round all the out of date backups
select @eID = 0 ,
@eMaxID = coalesce(max(ID), 0)
from #ExistingBackups

while @eID < @eMaxID begin select @eID = min(ID) from #ExistingBackups where ID > @eID
select @eName = Name from #ExistingBackups where ID = @eID

select @sql = 'del ' + @Path + @eName
exec master..xp_cmdshell @sql
end
delete #ExistingBackups

-- now do the backup
select @sql = @Path + @Name + '_' + @Type + '_'
+ convert(varchar(8),getdate(),112) + '_'
+ replace(convert(varchar(8),getdate(),108),':','') + '.bak'
if @Type = 'Full'
backup database @Name
to disk = @sql
else
backup log @Name
to disk = @sql
end

go

Tuesday, February 15, 2011

[T-SQL] Database backup procedure - advanced

I have got this script from one of the blogs:

if exists (select * from sysobjects where id = object_id(N'[dbo].[spBackupAllDatabases]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[spBackupAllDatabases]
go

Create Procedure spBackupAllDatabases
@Path varchar(128) ,
@Type varchar(4) -- Full / Log
as
/*
Backup file format
_Full_yyyymmdd_hhmmss.bak
_Log_yyyymmdd_hhmmss.bak

exec spBackupAllDatabases 'c:\SQLBackups\', 'Full'
*/
/*
drop table DatabaseBackup

Create table DatabaseBackup
(
Name varchar(128) primary key nonclustered ,
BackupFlagFull varchar(1) not null check (BackupFlagFull in ('Y','N')) ,
BackupFlagLog varchar(1) not null check (BackupFlagLog in ('Y','N')) ,
RetentionPeriodFull datetime not null ,
RetentionPeriodLog datetime not null
)
*/
set nocount on
declare @sql varchar(1000)

-- Get all database names
create table #DBName
(
ID int identity (1,1) ,
Name varchar(128) not null ,
RetentionPeriod datetime null
)

insert #DBName
(Name)
select name
from master..sysdatabases

-- Include any new databases in the backup
insert DatabaseBackup
(
Name ,
BackupFlagFull ,
BackupFlagLog ,
RetentionPeriodFull ,
RetentionPeriodLog
)
select #DBName.Name ,
'Y' ,
'N' ,
'7 jan 1900' , -- default one week
'1 jan 1900'
from #DBName
left outer join DatabaseBackup
on DatabaseBackup.Name = #DBName.Name
where DatabaseBackup.Name is null
and lower(#DBName.Name) <> 'tempdb'

-- Remove any non-existant databases
delete DatabaseBackup
where not exists
(
select *
from #DBName
where #DBName.Name = DatabaseBackup.Name
)

delete #DBName

create table #ExistingBackups
(
Name varchar(128) ,
ID int identity (1,1)
)

-- loop through databases
declare @Name varchar(128) ,
@RetentionPeriod datetime ,
@LastBackupToKeep varchar(8) ,
@ID int ,
@MaxID int

insert #DBName
(Name, RetentionPeriod)
select Name, case when @Type = 'Full' then RetentionPeriodFull else RetentionPeriodLog end
from DatabaseBackup
where (@Type = 'Full' and BackupFlagFull = 'Y')
or (@Type = 'Log' and BackupFlagLog = 'Y')

select @MaxID = max(ID) ,
@ID = 0
from #DBName

while @ID < @MaxID begin -- get next database to backup select @ID = min(ID) from #DBName where ID > @ID

select @Name = Name ,
@RetentionPeriod = RetentionPeriod
from #DBName
where ID = @ID

-- Delete old backups
delete #ExistingBackups
select @sql = 'dir /B ' + @Path
select @sql = @sql + @Name + '_' + @Type + '*.*'

insert #ExistingBackups exec master..xp_cmdshell @sql

if exists (select * from #ExistingBackups where Name like '%File Not Found%')
delete #ExistingBackups

select @LastBackupToKeep = convert(varchar(8),getdate() - @RetentionPeriod,112)
delete #ExistingBackups where Name > @Name + '_' + @Type + '_' + @LastBackupToKeep

declare @eID int ,
@eMaxID int ,
@eName varchar(128)

-- loop round all the out of date backups
select @eID = 0 ,
@eMaxID = coalesce(max(ID), 0)
from #ExistingBackups

while @eID < @eMaxID begin select @eID = min(ID) from #ExistingBackups where ID > @eID
select @eName = Name from #ExistingBackups where ID = @eID

select @sql = 'del ' + @Path + @eName
exec master..xp_cmdshell @sql
end
delete #ExistingBackups

-- now do the backup
select @sql = @Path + @Name + '_' + @Type + '_'
+ convert(varchar(8),getdate(),112) + '_'
+ replace(convert(varchar(8),getdate(),108),':','') + '.bak'
if @Type = 'Full'
backup database @Name
to disk = @sql
else
backup log @Name
to disk = @sql
end

go

Wednesday, October 13, 2010

[T-SQL] Stored Procedure Advantage

One of the SQL Expert was asked this question and which one is the best advantage, so here is the answer:

There are many advantages of Stored Procedures. I was once asked what do I think is the most important feature of Stored Procedure? I have to pick only ONE. It is tough question.
I answered : Execution Plan Retention and Reuse (SP are compiled and their execution plan is cached and used again to when the same SP is executed again)

Not to mentioned I received the second question following my answer : Why? Because all the other advantage known (they are mentioned below) of SP can be achieved without using SP. Though Execution Plan Retention and Reuse can only be achieved using Stored Procedure only.

Execution plan retention and reuse
Query auto-parameterization
Encapsulation of business rules and policies
Application modularization
Sharing of application logic between applications
Access to database objects that is both secure and uniform
Consistent, safe data modification
Network bandwidth conservation
Support for automatic execution at system start-up
Enhanced hardware and software capabilities
Improved security
Reduced development cost and increased reliability
Centralized security, administration, and maintenance for common routines

Monday, October 11, 2010

[T-SQL] Create and Encrypted Stored Procedure

An answer to a very simple question , how to create a stored procedure any problem if we create it.

Here is the script

USE AdventureWorks
GO
-- Create Encyrpted SP
CREATE PROCEDURE uspEnc
WITH ENCRYPTION
AS
SELECT *
FROM Sales.SalesOrderDetail
UNION
SELECT *
FROM Sales.SalesOrderDetail
GO
-- Execute SP
EXEC uspEnc
GO

Question: if any stored procedure is encrypted can we see its definition in Activity Monitor.
Answer: No

Question: Any tool to decrypt the SP
Answer: SQL Decryptor, Decrypt SQL

Question: Should a DBA recommend it
Answer: Encrypted stored procedures are horrible. You can’t see what queries are executed, you don’t have a clue what the execution plan is. So if users are complaining about the slowness of the system, and everything is encrypted… then it will not be possible to look into it.

[T-SQL] Get Numbers from Alpha Numeric Value

Here is the procedure i just saw from one of the sql expert blog that will rreturn Numbers from Alpha Numeric Values.

CREATE PROCEDURE [dbo].[GetNumbers]
@alpha VARCHAR(50),
@decimal DECIMAL(14, 5) OUTPUT
AS BEGIN
SET NOCOUNT ON;
DECLARE @ErrorMsg VARCHAR(50)
DECLARE @Pos INT
DECLARE @CommaPos INT
DECLARE @ZeroExists INT
DECLARE @alphaReverse VARCHAR(50)
DECLARE @NumPos INT
DECLARE @Len INT
-- 1 Reverse the alpha in order to get the last position of a numeric value
SET @alphaReverse = REVERSE(@alpha)
-- 2 Get the last position of a numeric figure
SET @NumPos = PATINDEX('%[0-9]%', @alphaReverse)
-- 3 Get the lenght of the string
SET @Len = LEN(@alpha)
-- 4 Add a comma after the numeric data in case it's no decimal number
SET @alpha = SUBSTRING(@alpha, 1, (@Len - @NumPos + 1))
+ ','
+ SUBSTRING(@alpha, (@Len - @NumPos + 2), 50)
-- Check if there is a zero (0) in the @alpha, then we later set the @decimal to 0
-- if it's 0 after the handling, else we set @decimal to NULL
-- If 0 no match, else there is a match
SET @ZeroExists = CHARINDEX ( '0' , @alpha ,1 )
-- Find position of , (comma)
SET @CommaPos = 1
SET @CommaPos = PATINDEX('%,%', @alpha)
IF (@CommaPos = '') BEGIN
SET @CommaPos = 20
END
SET @Pos = PATINDEX('%[^0-9]%',@alpha)
-- Replaces any aplha with '0' since we otherwice can't keep track of where the decimal
-- should be put in. We assume the numeric number has no aplhe inside. The regular way
-- to solve this is to replace with ”, but then we miss the way to find the place to
-- put in the decimal.
WHILE (@Pos > 0) BEGIN
SET @alpha = STUFF(@alpha, @pos, 1, '0')
SET @Pos = PATINDEX('%[^0-9]%',@alpha)
END
IF (@alpha IS NOT NULL AND @alpha != '') BEGIN
SET @decimal = CONVERT(DECIMAL(14, 5), SUBSTRING(@alpha, 1, (@CommaPos - 1))
+ '.'
+ SUBSTRING(@alpha, (@CommaPos + 1), 20))
END
-- Since we in this case don't want to set 0 if where is no numeric value, we set NULL to be safe
IF (@decimal = 0 AND @ZeroExists = 0) BEGIN
SET @decimal = NULL
END
END
GO

If you run above SP as shown below it will work
DECLARE @myVal DECIMAL(14,5)
EXEC [GetNumbers] 'ABC455,88ghf', @myVal OUTPUT
SELECT @myVal RValue

RValue
---------------------------------------
455.88000

Thursday, October 7, 2010

[T-SQL] Clear Cache and Buffer of Stored Procedure

Use DBCC FREEPROCCACHE to clear the procedure cache. Freeing the procedure cache would cause, for example, an ad-hoc SQL statement to be recompiled rather than reused from the cache. If observing through SQL Profiler, one can watch the Cache Remove events occur as DBCC FREEPROCCACHE goes to work. DBCC FREEPROCCACHE will invalidate all stored procedure plans that the optimizer has cached in memory and force SQL Server to compile new plans the next time those procedures are run.

Use DBCC DROPCLEANBUFFERS to test queries with a cold buffer cache without shutting down and restarting the server. DBCC DROPCLEANBUFFERS serves to empty the data cache. Any data loaded into the buffer cache due to the prior execution of a query is removed.

DBCC FREEPROCCACHE
DBCC DROPCLEANBUFFERS