Autogrowth option for SQL Server database files

It is not recommended to keep “In Percent” File Growth option for database files. If “In Percent” option is used for any database file and if the file size is very big, it may cause performance degradation during the file growth phase. It may not be a very big problem if “Instant File Initialization” is used but “Instant File Initialization” is only used for data files not log files. So it is always better to use “In Megabytes” option for File Growth.

It is recommended to keep 1024MB for data files and 256MB for log files. Log files are really important because when the transaction occurs, it is written to memory and log files first. Log files are very important because of point-in-time recovery and there shouldn’t be any latency on the log file.

The query below can be used to check the next auto growth size for each data and log files. And if is_percent_growth column equals to “Yes”, File Growth option can be selected as “In Megabytes”

 --auto growth percentage for data and log files
select DB_NAME(files.database_id) database_name, files.name logical_name, 
CONVERT (numeric (15,2) , (convert(numeric, size) * 8192)/1048576) [file_size (MB)],
[next_auto_growth_size (MB)] = case is_percent_growth
    when 1 then CONVERT(numeric(18,2), (((convert(numeric, size)*growth)/100)*8)/1024)
    when 0 then CONVERT(numeric(18,2), (convert(numeric, growth)*8)/1024)
end,
is_read_only = case is_read_only 
    when 1 then 'Yes'
    when 0 then 'No'
end,    
is_percent_growth = case is_percent_growth 
    when 1 then 'Yes'
    when 0 then 'No'
end, 
physical_name
from sys.master_files files
where files.type in (0,1)
and files.growth != 0

• Anonymous
  March 12, 2013
  Hi, you stated above that "It is recommended to keep 1024KB for data files " but the image shows 1024 MB. IS KB a typo?Good article,Thanks
• Anonymous
  March 13, 2013
  Thanks for letting us know about the typo. I corrected it.
• Anonymous
  May 23, 2013
  I already set autogrowth in my production server. and now I want to change the autogrowth  value. Is there any possibility of errors or corrupt  after changing the value? or are there any basic that need to be done before changing the value? Because i don't want to make mistake on production server.Thanks.
• Anonymous
  May 25, 2013
  It is an online operation. So you can change the value and apply it. It is just a database property change so it will not cause any database corruption.
• Anonymous
  August 05, 2013
  HI,Does this recommendation holds true in case of data warehousing as well where data can be from 10 MB to 10 PB?Thanks
• Anonymous
  September 05, 2013
  After changing the Auto Growth setting to "In Megabytes: 1024MB", the "is_percent_growth" column should display "No" instead of "Yes".On the other hand, can you also provide the screenshot of setting the Log file to "In Megabytes: 256MB" for consistency ?
• Anonymous
  November 11, 2013
  Great script -- perfect for reviewing a badly managed  Estate I've recently inherited. Thanks Cardy
• Anonymous
  January 07, 2014
  Thanks for the info and the query. It's an eye opener to run it on different servers to see our autogrowth settings all over the place. I like the blanket settings of 1024MB for data files and 256MB for log files. Can you tell us the origin or resource of the sizes? Thanks, Darren
• Anonymous
  April 13, 2014
  Hi Batuhan,Thanks for the article. Would you mind posting a link to the KB article that recommends these file size growths?Thanks,Colin
• Anonymous
  July 21, 2014
  I would also like to know the rationale behind the recommended growth sizes of 1024MB (data) and 256MB (log). I am creating a policy to check for autogrowth (set to KB), and also wanted to include a check for growth sizes so this background info would be great to know. Thanks
• Anonymous
  December 23, 2014
  The comment has been removed