What limitations arise when creating indexes on all columns of a table in SQL, and why is this not recommended?

Creating indexes on all columns of a table in SQL leads to several serious limitations and problems:

• Write performance degrades. Each index needs to be updated during insert, update, or delete operations, which slows down write operations.
• Storage space increases. Indexes require additional disk space, and having many indexes on all columns can significantly increase the database size.
• Query planner can get confused. Excessive indexes complicate the selection of the optimal query execution plan.
• Not all columns are suitable for indexing. For example, columns with a large number of unique values or frequently changing columns may not be efficiently indexed.

For these reasons, it is recommended to create indexes only on those columns that are frequently used in WHERE conditions, JOINs, or ORDER BY clauses to optimize specific queries.