“Solve Performance Issues With Index Disabling: Lesson Learned #341”

Lesson Learned #341: Index Disabled vs Performance Issues
Analyzing Performance Issues Caused by Index Disabling
When it comes to managing databases, indexes are an important tool for improving query performance. However, if not configured correctly, indexes can also be the source of performance bottlenecks and other issues. In this blog post, we will take a closer look at the performance implications of disabling indexes.

What is an Index?
An index is a data structure that stores information about the rows in a database table. They are used to quickly locate records without having to perform a full table scan. Indexes are usually created based on one or more columns in a table and can be either clustered or non-clustered.

Why Would You Disable an Index?
There are several reasons why an index might need to be disabled. Some of the most common reasons include:

* To improve the performance of certain queries.
* To reduce the size of the index.
* To reduce the amount of disk space used by the index.
* To reduce the amount of time required to insert or update data.

Potential Performance Impact of Index Disabling
While disabling an index can sometimes improve the performance of certain queries, it can also have a negative impact on the overall performance of the database. For example, if an index is disabled, the database engine will have to perform a full table scan whenever a query is executed. This can lead to slower query execution times and increased resource consumption.

Best Practices for Index Disabling
When disabling an index, it is important to keep the following best practices in mind:

* Disable indexes only when it is absolutely necessary.
* Disable indexes only for the duration of the operation that requires the index to be disabled.
* Monitor the performance of the database before and after the index is disabled.
* Re-enable the index after the operation is complete.

Conclusion
Indexes are an important tool for improving query performance, but they can also be a source of performance bottlenecks and other issues. When disabling an index, it is important to keep the best practices outlined in this blog post in mind in order to ensure that the database performance is not negatively impacted.
References:
Lesson Learned #341: Index Disabled vs Performance issues
1. Microsoft 365 Performance
2. Microsoft 365 Index Disabled
3. Microsoft 365 Trou