Category: SQL Scripts

  • Linked Server in SQL Server

    A linked server configuration enables SQL Server to execute commands/T-SQL statements against OLE DB data sources on remote servers. You can query heterogeneous databases using linked server.

    Advantage of Linked Server
    Remote server access
    You can execute distributed queries, updates, commands, and transactions on heterogeneous data sources using linked server
    The ability to address diverse data sources similarly.


    -- Below procedure will create linked server to communicate with access

    Sp_addlinkedserver ‘Lnk_AccessDB’, ‘Access’, ‘Microsoft.Jet.OLEDB.4.0’,

    ‘c:\db1.mdb’

    -- query the linked server

    SELECT *

    FROM   lnk_accessdb...tb1

    -- Below query will drop the linked server

    EXEC Sp_dropserver ‘Lnk_AccessDB’ 

  • Backup Start Date Time and Finish Date Time

    As best practice it is recommended that you have to backup date time with the backup file name so anyone can get the idea of Backup creation.

    Sometimes due some issue we took backup without specifying the datetime with the backup file name so during restore we are unsure that how much data backed up in the backup file, type of backup, Is it Copy only and more.

    SQL Server stores the Backup Metadata into backup header. You can restore header only command to get the required information.

    RESTORE headeronly FROM disk = ‘c:\jshah.bak’ 

    Column Name Values Description
    BackupName NULL  
    BackupDescription NULL  
    BackupType 1 Backup type:
    1 = Database
    2 = Transaction log
    4 = File
    5 = Differential database
    6 = Differential file
    7 = Partial
    8 = Differential partial
    ExpirationDate NULL  
    Compressed 0 0 = Un-Compressed Backup
    1 = Compressed Backup
    Position 1  
    DeviceType 2  
    UserName JShah  
    ServerName SQLDBPool  
    DatabaseName jshah  
    DatabaseVersion 655  
    DatabaseCreationDate 12/31/10 9:55 AM  
    BackupSize 1453056  
    FirstLSN 28000000006000100  
    LastLSN 28000000013000000  
    CheckpointLSN 28000000006000100  
    DatabaseBackupLSN 0  
    BackupStartDate 12/31/10 10:06 AM  
    BackupFinishDate 12/31/10 10:06 AM  
    SortOrder 52  
    CodePage 0  
    UnicodeLocaleId 1033  
    UnicodeComparisonStyle 196609  
    CompatibilityLevel 100  
    SoftwareVendorId 4608  
    SoftwareVersionMajor 10  
    SoftwareVersionMinor 0  
    SoftwareVersionBuild 2757  
    MachineName SQLDBPool  
    Flags 512 1 = Log backup contains bulk-logged operations.
    2 = Snapshot backup.
    4 = Database was read-only when backed up.
    8 = Database was in single-user mode when backed up.
    16 = Backup contains backup checksums.
    32 = Database was damaged when backed up, but the backup operation was requested to continue despite errors.
    64 = Tail log backup.
    128 = Tail log backup with incomplete metadata.
    256 = Tail log backup with NORECOVERY.
    BindingID 85A5505D-ADB1-4B33-A181-549DC520A0F8  
    RecoveryForkID 03DE5437-1E27-4885-9011-91CFED12338A  
    Collation SQL_Latin1_General_CP1_CI_AS  
    FamilyGUID 03DE5437-1E27-4885-9011-91CFED12338A  
    HasBulkLoggedData 0 1 = Yes
    0 = No
    IsSnapshot 0 1 = Yes
    0 = No
    IsReadOnly 0 1 = Yes
    0 = No
    IsSingleUser 0 1 = Yes
    0 = No
    HasBackupChecksums 0 1 = Yes
    0 = No
    IsDamaged 0 1 = Yes
    0 = No
    BeginsLogChain 0 1 = Yes
    0 = No
    HasIncompleteMetaData 0 1 = Yes
    0 = No
    IsForceOffline 0 1 = Yes
    0 = No
    IsCopyOnly 0 1 = Yes
    0 = No
    FirstRecoveryForkID 03DE5437-1E27-4885-9011-91CFED12338A  
    ForkPointLSN NULL  
    RecoveryModel FULL  
    DifferentialBaseLSN NULL  
    DifferentialBaseGUID NULL  
    BackupTypeDescription Database  
    BackupSetGUID 62EB4399-C119-42C2-91F1-BF0FF19CB896  
    CompressedBackupSize 1453056  

  • KILL SQL Server 2000 Blocking SPID and Records it details

    Problem
    Today I got an email from one of my blog reader; they have an application developed with VB6.0 and SQL Server 2000. Application was developed long back and now their database size is increased as well. Due un-efficient coding they are getting blocking issue and stuck all their application transactions. He asked for writing a query which will execute by SQL Server Agent at every 1 minute and will KILL the culprit SPID. He also wants me to store the KILL transaction history as well.

    As a solution I have written below query for him and which working fine now.

    -- Create below table in master database
 create table blkHistory
(
	SPID int,
	blocked int,
	killedSPID int,
	date datetime default getdate(),
	querytext varchar(8000)
)


-- add below code in to job command text box
declare @SPID as int,
        @blocked as int,
        @KilledSPID as int

declare @querytext as varchar(8000), @sql nvarchar(400)

select @SPID = spid,@blocked = blocked from sysprocesses where blocked <> 0

--select spid,blocked from sysprocesses where blocked <> 0

select @sql = 'KILL ' + cast (@blocked as nvarchar(100))

DECLARE @Handle binary(20)
SELECT @Handle = sql_handle FROM sysprocesses WHERE spid = @blocked

SELECT @querytext = text FROM ::fn_get_sql(@Handle)

EXECUTE sp_executesql @SQL

If @SPID > 0
begin
insert into blkHistory(SPID,blocked,KilledSPID,querytext)
values (@SPID,@blocked,@blocked,@querytext)
end

--you can use below query to retrieve datafrom blocking history
select * from master..blkHistory

  • How to find database restore history from MSDB?

    MSDB database is used by SQL Server Agent for scheduling alerts and jobs and by other features such as Service Broker and Database Mail. Again SQL Server is using MSDB for storing the history of backup, restore, log-shipping details and more…

    You can query the MSDB as below to get the details about the SQL Server restore history.

    SELECT TOP 10 *
FROM restorehistory WITH (nolock)WHERE (destination_database_name = 'Database Name')ORDER BY restore_date DESC
All Databases

SELECT TOP 10 * FROM restorehistory WITH (nolock)ORDER BY restore_date DESC