If an ORDER BY clause is not used, how are the rows returned?

When an ORDER BY clause is not specified in a query, the database management system determines the order in which the rows are returned based on its internal algorithms and optimization strategies. This means that the rows can be returned in an order that the system finds most efficient for processing, which might vary depending on several factors such as indexes, the way data is stored, or how the query is executed. This behavior ensures optimal performance during data retrieval, as the system can prioritize speed over a specific order of the results.

It's important to note that without the ORDER BY clause, there is no guarantee of any specific ordering of the results, meaning that repeated executions of the same query could yield results in different orders.