For which kind of operations should indexes not be created to avoid performance penalties?

Creating indexes significantly boosts the performance of read operations, such as queries, by allowing the database to efficiently locate the required data. However, when it comes to operations like adding, deleting, or modifying records, the benefits of indexing change.

For frequent add, delete, or update operations, having indexes can result in performance penalties. This is because every time a record is modified, the database has to update the indexes associated with that record, which adds overhead. The more indexes there are on a table, the more updates may take place to maintain those indexes, which can slow down the operation speeds of adding or modifying data.

In contrast, other operations such as batch processing of data or data import from external sources may also be affected by indexes, but they are usually designed to handle larger sets of data more optimally despite the potential overhead. Complex query operations benefit significantly from indexes, making them more efficient since they help retrieve data quickly. Therefore, for the frequent operations of adding, deleting, or modifying records, it's advisable to minimize or avoid index creation to maintain optimal performance.