Why shrinking the data file is bad?

Hi All,
Why shrinking the data file is bad?
If it is bad, Then why SQL server has this option?

There are several reasons why shrinking is bad. One of the reasons were recorded already by Louis Jordan around 1950 where he sang What's the Use of Getting Sober, when You Are Gonna Get Drunk Again?" That is, why shrink something that will grow
again? Growing a database file takes some resources, since it has to be zero-initialised. For a data file this can be avoided by granting the service account for SQL Server the permission "Perform Volume Operations" (if I recall the name correctly).
For a log file it is unevitable. While SQL Server grows the file, this causes a standstill for the process that triggered the file to grow, and can easily cause a bigger outage.
Another reason that shirnk is bad is that it adds a lot of fragmentation to the database. In difference to the above, there is no reason it has to be that way. It's simply not an optimal implementation.
Shrinking can be really poor when you have big LOB columns.
So why does shrink exist? Because sometimes, shrinking a data file or a log file is a perfectly legit operation. Say that you have a transaction database, and you decide to move transactions that are more than 12 months old to an archive database,
and you also implement a process to move data to the archive database on quarterly basis. Before you implemented the archive database, the transaction database was 1.5 TB, but after you moved ten years worth of data, you now have a 250 GB database. In this
case, it would be perfectly reasonable to shrink the data file to, say, 300 GB to make it more managable.
Or say that you make a change to your reindex job so that it runs with bulk_logged recovery rather than full. This may permit you to reduce the size of the log file with 50% (a number taken out of thin air).
There are lot of other situations, but the key is: you have reason to believe that the data file will stay within the size you shrink it to. Some people are obesseed with space and shrink whenever they get the occasion, but that is a bad idea.
Erland Sommarskog, SQL Server MVP, [email protected]

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Hi,
But I would like to know, Is there any things which I need to consider
in terms of number of data files (Any Formula to arrive a total number of data files
for the better performance in SQL database level).
You can refer Topic "Number and Size of SQL Server Data Files" of this [Best Practice document|http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/4ab89e84-0d01-0010-cda2-82ddc3548c65&overridelayout=true] (Page no.37 to 44 ). I hope you will get all the required information ,which can be considered for File Management in SQL server.
Also you can refer the following SAP Notes to get more information.
Note 987961 - FAQ: SQL Server I/O performance
Note 363018 - File management for SQL Server
Note 1488135 - Database compression for SQL Server
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import java.io.*;
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jan07 wrote:
anybody help me out to solve this ,,Solve what?
Don't just dump a pile of unformatted code and expect someone to magically fix it for you.
Post code, hightlight it and click the CODE button to retain formatting
Include error messages if you get them
Ask an actual question

Why shrinking the data file is bad?

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