As a SQL Server consultant, I often come across various performance issues that clients face with their database servers. One particular project stands out in my mind, where the main objective was to improve the overall performance of the database server. During this project, I encountered a common mistake that many database administrators make – shrinking the database.

Before we dive into the details, let me clarify that I completely agree with the notion that shrinking a database is bad. However, in this blog post, I want to provide a comprehensive explanation as to why shrinking your SQL Server database can have detrimental effects on its performance.

During my visit to the client’s office, I had a conversation with the resident DBA about the index fragmentation. To my surprise, the level of fragmentation was the highest I had ever seen. When I asked the DBA if they had ever performed index maintenance, he admitted that they hadn’t done it in over a year. This was quite astonishing to me, as regular index maintenance is crucial for optimal performance.

After discussing the issue with the DBA, I quickly provided him with a script to rebuild and reorganize the indexes. We executed the script after business hours, and it took around 1.5 hours to complete. Once the task was finished, I checked the fragmentation levels, and they had significantly improved. Some of the large tables even showed near-zero fragmentation. The DBA confirmed that certain reports were running faster than before, which was a positive outcome.

Feeling satisfied with the progress made on the first day, I left the client’s location and returned to my hotel. However, the next day, during a meeting with the company director, I was informed that the indexes were still fragmented. I ran my script again to check the fragmentation levels, and to my surprise, they were the same as before. I was perplexed and couldn’t understand what had gone wrong.

After thoroughly investigating the issue, I stumbled upon a piece of code that was causing the problem. The code was executing the DBCC SHRINKDATABASE command on the entire database. This command shrinks the database files, but it also causes heavy fragmentation of the tables, resulting in reduced performance.

Once I removed the code and reran the index maintenance script, the issue was resolved. For the next five days, the database performed flawlessly without any problems.

This experience reinforced the fact that shrinking a database is not recommended. It not only leads to heavy fragmentation but also requires additional effort to rebuild and reorganize indexes. In most cases, there is no real need to shrink a database, and doing so can have negative consequences on performance.

So, what should you do instead of shrinking your database? The key is to regularly perform index maintenance tasks, such as rebuilding and reorganizing indexes. This helps to keep the indexes optimized and ensures optimal performance of your SQL Server database.

In conclusion, I strongly advise against shrinking your SQL Server database. It may seem like a quick fix to free up disk space, but it can have severe repercussions on the performance of your database. Instead, focus on implementing regular index maintenance tasks to keep your database running smoothly.