Database Query Help for MS SQL Server -- 2

I want to get data usage at a subscriber level and on a user level. Some of my tables have a field to identify the subscriber and some of my tables have fields to identify the user. I'd like a way to calculate the total storage for the user and for the subscriber in under a second. I have already created some code but it needs to be optimized. There has to be a better way to do this. This is for MS SQL Server. You will not be given access to my server or database.

I am looking for a freelancer who can provide database query help for optimizing performance in MS SQL Server.

Specific requirements for the project include:
- Creating queries from scratch to improve performance
- Advanced experience with MS SQL Server
- Ability to identify and fix errors in existing queries
- Providing general guidance on optimizing database queries

Ideal skills and experience for the job include:
- Advanced proficiency in MS SQL Server
- Strong knowledge of query optimization techniques
- Experience in troubleshooting and fixing query performance issues
- Ability to analyze and interpret query execution plans
- Familiarity with indexing strategies and database tuning techniques

If you have the expertise and experience in optimizing database queries in MS SQL Server, I would love to hear from you. Please provide examples of previous projects or relevant certifications.