4

I have a database its size around 200G and it is heavy loaded with many inserts happens every day (it is grow around 3 to 4 GB every day), but the Auto-Grow setting is set to 1 MB.

I think this is a problem and I think if I set it to 1GB it will increase the performance and capability, is that right?

I think with 1MB auto-grow the database will be always busy to allocate a new space, is that right ? Any suggestion for best practical way to increase the performance?

Thanks all

3

You are correct since you figured out your database grows approx 1G its really bad to keep autogrowth settings to 1MB. When SQL Server performs an auto-grow event, the transaction that triggered the auto-grow event will have to wait until the auto-grow event completes before the transaction can finish. These auto-growth events cause your performance to degrade a little when an auto-grow event is taking place. For this reason it is best if you can size your database appropriately so auto-growth events rarely occur.

Make sure you have instant file initialization for Data files

The best thing is you can do is presize your database so that it does not have to encounter any autogrowth events like if you know it would grow upto 30G in month please allocate that space to datafile before hand.

You can use below query to check auto growth events. This query is taken from This Link I would like you to spend time and read this article.

DECLARE @filename NVARCHAR(1000);
DECLARE @bc INT;
DECLARE @ec INT;
DECLARE @bfn VARCHAR(1000);
DECLARE @efn VARCHAR(10);

-- Get the name of the current default trace
SELECT @filename = CAST(value AS NVARCHAR(1000))
FROM ::fn_trace_getinfo(DEFAULT)
WHERE traceid = 1 AND property = 2;

-- rip apart file name into pieces
SET @filename = REVERSE(@filename);
SET @bc = CHARINDEX('.',@filename);
SET @ec = CHARINDEX('_',@filename)+1;
SET @efn = REVERSE(SUBSTRING(@filename,1,@bc));
SET @bfn = REVERSE(SUBSTRING(@filename,@ec,LEN(@filename)));

-- set filename without rollover number
SET @filename = @bfn + @efn

-- process all trace files
SELECT
  ftg.StartTime
,te.name AS EventName
,DB_NAME(ftg.databaseid) AS DatabaseName  
,ftg.Filename
,(ftg.IntegerData*8)/1024.0 AS GrowthMB
,(ftg.duration/1000)AS DurMS
FROM ::fn_trace_gettable(@filename, DEFAULT) AS ftg
INNER JOIN sys.trace_events AS te ON ftg.EventClass = te.trace_event_id  
WHERE (ftg.EventClass = 92  -- Date File Auto-grow
    OR ftg.EventClass = 93) -- Log File Auto-grow
ORDER BY ftg.StartTime
  • Yes they would have to wait. That is why I said its better to preallocate that much free space to data file so that it keeps that much free space and this would minimize autogrowth. 20 sec will not always be the time it can be few seconds as well depends on factors – Shanky Nov 16 '14 at 12:12
9

1 MB is not the right choice for autogrowth !

You should always set auto growth to a sensible value that suits your environment. I tend to capture the autgrowth value for a month and then average it out to give me a ball park figure of autogrowth for my database .

I have provided a sample script here as well. Also refer to Mike Walsh's answer.

The default trace keeps track of AUTOGROWTH events out-of-the box. Below script will give you a good starting point.

Also, Instant file initialization is a boon when auto growth kicks in (ONLY applies to data files).

IF OBJECT_ID('tempdb..#autogrowthTotal') IS NOT NULL
    DROP TABLE #autogrowthTotal;
IF OBJECT_ID('tempdb..#autogrowthTotal_Final') IS NOT NULL
    DROP TABLE #autogrowthTotal_Final;

DECLARE @filename NVARCHAR(1000);
DECLARE @bc INT;
DECLARE @ec INT;
DECLARE @bfn VARCHAR(1000);
DECLARE @efn VARCHAR(10);

-- Get the name of the current default trace
SELECT @filename = CAST(value AS NVARCHAR(1000))
FROM ::fn_trace_getinfo(DEFAULT)
WHERE traceid = 1 AND property = 2;

-- rip apart file name into pieces
SET @filename = REVERSE(@filename);
SET @bc = CHARINDEX('.',@filename);
SET @ec = CHARINDEX('_',@filename)+1;
SET @efn = REVERSE(SUBSTRING(@filename,1,@bc));
SET @bfn = REVERSE(SUBSTRING(@filename,@ec,LEN(@filename)));

-- set filename without rollover number
SET @filename = @bfn + @efn

-- process all trace files
SELECT
  ftg.StartTime
  ,te.name AS EventName
,DB_NAME(ftg.databaseid) AS DatabaseName  
,ftg.[FileName] as LogicalFileName
,(ftg.IntegerData*8)/1024.0 AS GrowthMB
,(ftg.duration/1000)AS DurMS
,mf.physical_name AS PhysicalFileName
into #autogrowthTotal
FROM ::fn_trace_gettable(@filename, DEFAULT) AS ftg
INNER JOIN sys.trace_events AS te ON ftg.EventClass = te.trace_event_id 
join sys.master_files mf on (mf.database_id = ftg.databaseid) and (mf.name = ftg.[FileName]) 
WHERE (ftg.EventClass = 92  -- Data File Auto-grow
    OR ftg.EventClass = 93) -- Log File Auto-grow
ORDER BY ftg.StartTime

select count(1) as NoOfTimesEventFired
        , CONVERT(VARCHAR(10), StartTime, 120) as StartTime
        , EventName
        , DatabaseName
        , [LogicalFileName]
        , PhysicalFileName
        , SUM(GrowthMB) as TotalGrowthMB
        , SUM(DurMS) as TotalDurationMS
into #autogrowthTotal_Final
from #autogrowthTotal
group by CONVERT(VARCHAR(10), StartTime, 120),EventName,DatabaseName, [LogicalFileName], PhysicalFileName
--having count(1) > 5 or SUM(DurMS)/1000 > 60 -- change this for finetuning....
order by CONVERT(VARCHAR(10), StartTime, 120)

select * from #autogrowthTotal_Final

Original Script from SimpleTalk.com (modified a bit to help me for reporting).

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