Indexes should not be used on very small tables.
When tables contain only a few records, indexes provide little or no benefit.
Indexes are not suitable for columns that change frequently.
Frequent updates cause index maintenance overhead.
Columns with low uniqueness are not good candidates for indexing.
Examples include gender or status columns.
Too many indexes slow down insert, update, and delete operations.
Each write operation must update all related indexes.
This reduces performance.
Indexes should be used thoughtfully.
Unnecessary indexing can harm performance.
Good index design balances speed and storage.