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Posts Tagged ‘Performance Tuning’

Syteline Performance Tuning–Part 1

January 21st, 2012 No comments

 

1) Update Statistics

You should always run the below command nightly

Exec sp_updatestats

2) Rebuild Index for key tables

It is worth to rebuild index for key tables regularly, like once a week.

DBCC DBREINDEX (ledger)
GO
DBCC DBREINDEX (item)
GO
DBCC DBREINDEX (customer)
GO
DBCC DBREINDEX (matltran)
GO
DBCC DBREINDEX (journal)
GO
DBCC DBREINDEX (ledger_all)
GO
DBCC DBREINDEX (matltran_amt)
GO

3) Defragment Index

Below script will defragment any index with over 20% logical fragmentation.  This should set to run weekly.

/*Perform a ‘USE <database name>’ to select the database in which to run
the script.*/
— Declare variables
SET NOCOUNT ON
DECLARE @tablename VARCHAR (128)
DECLARE @execstr VARCHAR (255)
DECLARE @objectid INT
DECLARE @indexid INT
DECLARE @frag DECIMAL
DECLARE @maxfrag DECIMAL
— Decide on the maximum fragmentation to allow
SELECT @maxfrag = 20.0
— Declare cursor
DECLARE tables CURSOR FOR
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = ‘BASE TABLE’
— Create the table
CREATE TABLE #fraglist (
ObjectName CHAR (255),
ObjectId INT,
IndexName CHAR (255),
IndexId INT,
Lvl INT,
CountPages INT,
CountRows INT,
MinRecSize INT,
MaxRecSize INT,
AvgRecSize INT,
ForRecCount INT,
Extents INT,
ExtentSwitches INT,
AvgFreeBytes INT,
AvgPageDensity INT,
ScanDensity DECIMAL,
BestCount INT,
ActualCount INT,
LogicalFrag DECIMAL,
ExtentFrag DECIMAL)
— Open the cursor
OPEN tables
— Loop through all the tables in the database
FETCH NEXT
FROM tables
INTO @tablename
WHILE @@FETCH_STATUS = 0
BEGIN
— Do the showcontig of all indexes of the table
INSERT INTO #fraglist
EXEC (‘DBCC SHOWCONTIG (”’ + @tablename + ”’)
WITH FAST, TABLERESULTS, ALL_INDEXES, NO_INFOMSGS’)
FETCH NEXT
FROM tables
INTO @tablename
END
— Close and deallocate the cursor
CLOSE tables
DEALLOCATE tables
— Declare cursor for list of indexes to be defragged
DECLARE indexes CURSOR FOR
SELECT ObjectName, ObjectId, IndexId, LogicalFrag
FROM #fraglist
WHERE LogicalFrag >= @maxfrag
AND INDEXPROPERTY (ObjectId, IndexName, ‘IndexDepth’) > 0
— Open the cursor
OPEN indexes
— loop through the indexes
FETCH NEXT
FROM indexes
INTO @tablename, @objectid, @indexid, @frag
WHILE @@FETCH_STATUS = 0
BEGIN
PRINT ‘Executing DBCC INDEXDEFRAG (0, ‘ + RTRIM(@tablename) + ‘,
‘ + RTRIM(@indexid) + ‘) – fragmentation currently ‘
+ RTRIM(CONVERT(varchar(15),@frag)) + ‘%’
SELECT @execstr = ‘DBCC INDEXDEFRAG (0, ‘ + RTRIM(@objectid) + ‘,
‘ + RTRIM(@indexid) + ‘)’
EXEC (@execstr)
FETCH NEXT
FROM indexes
INTO @tablename, @objectid, @indexid, @frag
END
— Close and deallocate the cursor
CLOSE indexes
DEALLOCATE indexes
— Delete the temporary table
DROP TABLE #fraglist
GO

4) Other script that should be run regularly

  • SLServerRestartSp – This stored procedure runs whenever the database server is
    restarted (since no one is logged in at that time) and performs general cleanup.
  • PurgeNextKeySp – Run this stored procedure to clean up the NextKeys table.
    NextKey records are inserted, never updated to get concurrency. This stored
    procedure cleans out the extra rows. DO NOT run this utility while others are using the
    system. The utility will lock users out, but you should log everyone out of the system
    before running this utility.

5) Scripts that can be used to return information related to performance

  • sp_who and sp_who2 – The stored procedure sp_who shows what SPID is blocked;
    sp_who2 shows who is blocking.
  • sp_helpindex (table_name) – Gives index information on a table.
  • DBCC OPENTRAN – Determines whether an open transaction exists within the log.
  • DBCC INPUTBUFFER (SPID) – Displays the last statement sent from a client to SQL
    Server.
  • dbcc showcontig (table_name) – This would show fragmentation information for a table.