Is it bad to hang indexes on all fields and why?

Attaching indexes to all fields is a bad practice for several reasons:

1. Increased write and update time: Each index needs to be updated during insert, delete, or modify operations, slowing down write operations.
2. Increased storage size: Indexes occupy additional disk space, which can lead to significant size increase.
3. Reduced efficiency: Excessive indexes can cause the query optimizer to choose inefficient execution plans.

Indexes should be created only on fields that are frequently used in WHERE, JOIN, or ORDER BY clauses to improve read performance without harming write operations.