How can I prevent phantom reads in my database?

What are phantom reads and why are they a problem in databases?

Phantom reads occur when a transaction reads a set of rows that match a certain condition, but another transaction inserts or deletes rows that affect that set before the first transaction is complete. This can lead to inconsistent data.

How can I prevent phantom reads in my database?

To prevent phantom reads, you can use higher isolation levels like Serializable, which ensures that no other transactions can insert or delete rows that would affect the current transaction's results.

Are there any downsides to using Serializable isolation level?

Yes, using Serializable can lead to increased locking and reduced concurrency, which may impact performance. It's important to balance data consistency with performance needs.

What are some alternatives to Serializable for preventing phantom reads?

Alternatives include using Repeatable Read isolation level, which prevents non-repeatable reads but may still allow phantom reads. You can also implement application-level locking or use optimistic concurrency control.