What does the 'rows' column indicate in an explain statement?

The 'rows' column in an explain statement provides an estimate of the rows examined during the execution of a query. This metric is crucial for understanding the efficiency and performance of a database operation. When analyzing queries, knowing how many rows are examined can help identify potential performance issues, as a high number of examined rows generally indicates that the query may not be optimized effectively. It assists developers in fine-tuning their queries for better execution plans, thus improving overall application performance.

In this context, the focus on how many rows are examined allows developers to gauge the amount of data the query engine needs to process to return the results. This insight is vital for optimizing queries and enhancing application performance, as it can help pinpoint where adjustments may need to be made, such as adding indexes or rewriting the query for efficiency.