MIN/MAX vs. ORDER BY LIMIT: Which is Faster for Finding Minimum or Maximum Values?

Database performance optimization: Efficiency comparison between MIN/MAX function and ORDER BY LIMIT clause

In the process of pursuing the performance and maintainability of database operations, developers often need to choose between different database operation methods. For finding the minimum or maximum value, two common methods are to use the MIN/MAX function and to use the ORDER BY clause in conjunction with the LIMIT clause.

For unindexed fields, the MIN() function performs faster because it only requires a full table scan of the table. ORDER BY and LIMIT require file sorting. In the case of large data sets, this difference will significantly affect performance, causing ORDER BY and LIMIT to be slower.

However, for indexed columns, the difference in speed between MIN() and ORDER BY LIMIT becomes less significant. However, execution plan analysis shows that the MIN() function utilizes the index more efficiently ('Select tables optimized away' and 'NULL' rows), while ORDER BY and LIMIT still rely on an ordered traversal of the index.

Overall, the MIN() function seems to be the better choice, as it has higher performance in the worst case and almost no difference in speed compared to ORDER BY LIMIT in the best case. It is also compliant with standard SQL, expressing expected results more clearly. However, when you need to develop a general-purpose operation to find the top or bottom values ​​of different columns, ORDER BY and LIMIT may be more advantageous and avoid writing case-specific operations.

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