When multiple connections attempt to update the same record concurrently, race conditions can arise. A common scenario involves incrementing a counter field, such as "tries." To ensure data integrity in such situations, it is crucial to implement mechanisms that address race conditions.
1. Atomic Updates:
MySQL supports atomic updates, which guarantee that an update operation succeeds or fails as a whole. This approach is recommended when it is sufficient to directly update the field without the need for selecting the current value first.
2. Row Locking:
This technique uses row-level locking to prevent multiple concurrent updates to the same row. By acquiring an exclusive lock, one connection can exclusively modify the row, while other connections must wait until the lock is released. This ensures that the field is updated correctly and avoids race conditions.
3. Version Scheme:
This approach introduces a version column to the table. When updating a row, the existing version is retrieved and the update is performed if the version matches. If the version has changed, it indicates that another connection has modified the row since the initial retrieval. In this case, the update is aborted, and the process must be repeated to retrieve the latest values and attempt the update again.
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