SQL SERVER DBA, Linux and Azure

Delete Bakups older than 1 day in SQL Server

--Delete Bakups older than 1 day in SQL Server

DECLARE @DeleteDate datetime

 SET @DeleteDate = DateAdd(day, -1, GetDate()) 

  EXECUTE master.sys.xp_delete_file 0, -- FileTypeSelected (0 = FileBackup, 1 = FileReport)

   N'C:\Backup\msdb', -- folder path (trailing slash)

    N'bak', -- file extension which needs to be deleted (no dot)

     @DeleteDate, -- date prior which to delete 

     1 -- subfolder flag (1 = include files in first subfolder level, 0 = not) 

Generate and change all SQL databases to a different compatibility level - Alter SQL Compatibility Level


SELECT name, compatibility_level  

FROM sys.databases where compatibility_level not in(120) -- SQL Server 2012 compatibility_level is 120

---------------------------------

SELECT name, compatibility_level  

FROM sys.databases 

---------------------------

/* Start Of Code */


DECLARE @SQL VARCHAR(max)  = ''

,             @CompLevel int = 120 -- Need to change the compatibility_level as per SQL Server version


SELECT @SQL += 'ALTER DATABASE ' + quotename(NAME) + ' SET COMPATIBILITY_LEVEL = ' + cast(@CompLevel as char (3)) + ';' + CHAR(10) + CHAR(13)

FROM sys.databases

WHERE 

--COMPATIBILITY_LEVEL not in(120) 

--and 

 compatibility_level <> @CompLevel


PRINT @SQL

--EXEC (@SQL)



/* End Of Code */

Finding an object in server in SQL Server using SP_MSFOREACHDB

 Today one of my friend asked me that she has created a stored procedure in a database, suddenly she has recognized she has forgotten the database in which the procedure was created. We suggested him to use the below query which searches each and every database in the server and returns the database name and the object name that is specified in where clause.

SP_MSFOREACHDB searches the objects in all databases in the server.

Example:

SP_MSFOREACHDB
'
USE ?
select
    ''?'' Database_Name
   , Name Object_name
from sys.procedures
WHERE name LIKE ''USP_Test''

Using SQL Server script to get list of users and their database roles in SQL Server

use Database_Name;

go 

SELECT  dPrinc.name AS [Members],dRole.name AS [Database Role Name]

FROM sys.database_role_members AS dRo  

JOIN sys.database_principals AS dPrinc  

    ON dRo.member_principal_id = dPrinc.principal_id  

JOIN sys.database_principals AS dRole  

    ON dRo.role_principal_id = dRole.principal_id;

About Update stats and Indexing Optimize in SQL Server

 Update stats:

Updates query optimization statistics on a table or indexed view. By default, the query optimizer already updates statistics as necessary to improve the query plan; in some cases, you can improve query performance by using UPDATE STATISTICS or the stored procedure sp_updatestats to update statistics more frequently than the default updates.

Updating statistics ensures that queries compile with up-to-date statistics. However, updating statistics causes queries to recompile. We recommend not updating statistics too frequently because there is a performance tradeoff between improving query plans and the time it takes to recompile queries. The specific tradeoffs depend on your application. UPDATE STATISTICS can use tempdb to sort the sample of rows for building statistics.

Indexing Optimize:

SQL Server Indexes are special data structures associated with tables or views that help speed up the query. 

Reorganize or rebuild a fragmented index in SQL Server by using SQL Server Management Studio or Transact-SQL. The SQL Server Database Engine automatically modifies indexes whenever insert, update, or delete operations are made to the underlying data. Over time, these modifications can cause the information in the index to become scattered in the database (fragmented). Fragmentation exists when indexes have pages in which the logical ordering, based on the key value, does not match the physical ordering inside the data file. Heavily fragmented indexes can degrade query performance and cause your application to respond slowly, especially scan operations.

You can remedy index fragmentation by reorganizing or rebuilding an index.