In a Database Management System (DBMS), a "subtract layer" is not a standard term, but it could refer to a layer or operation where data is filtered or excluded based on certain conditions. If you are referring to a layer or operation that involves subtracting or filtering data, here are some relevant tags that could be associated with it:
1. **Data Filtering**
2. **Set Operations**
3. **SQL Queries**
4. **Data Exclusion**
5. **Difference Operation**
6. **Query Optimization**
7. **Relational Algebra**
8. **Data Manipulation**
9. **Database Operations**
10. **Data Subtraction**
11. **Conditional Filtering**
12. **Data Transformation**
13. **Database Layers**
14. **Data Integrity**
15. **Query Execution**
If you are referring to a specific context or implementation of a "subtract layer," please provide more details so I can tailor the tags more accurately.