How to Ensure Consecutive Auto Increment Values with ON DUPLICATE KEY UPDATE?

Maintaining Consecutive Auto Increment Values despite ON DUPLICATE KEY

When utilizing the auto-increment feature in InnoDB with an ON DUPLICATE KEY UPDATE clause, you may encounter situations where the auto-increment field continues to increment even for duplicate key insertions. This can lead to gaps in the sequence of primary key values.

To address this issue, you can adjust the innodb_autoinc_lock_mode configuration setting to "0." This will set InnoDB to use the "traditional" auto-increment locking mode, ensuring that all INSERT statements assign consecutive values to AUTO_INCREMENT columns.

SET innodb_autoinc_lock_mode = 0;

However, it's important to note that while this approach can ensure consecutive auto-increment values, it may affect performance. Traditional auto-increment locking is more resource-intensive as it acquires a range lock on the table.

It's crucial to remember that the primary purpose of auto-increment IDs is to provide unique identifiers for rows, not to maintain a specific sequence. In your application, you should not rely on the auto-increment field to determine the order of rows. Instead, consider using a separate timestamp or other appropriate mechanisms to track the order of insertions.

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