What is the difference between transaction isolation levels?

Transaction isolation levels determine how much one transaction can see the changes made by others and influence possible anomalies:

• Read Uncommitted — the lowest level, a transaction can see uncommitted changes of other transactions (dirty read).
• Read Committed — a transaction only sees committed changes, preventing dirty reads, but non-repeatable reads are possible.
• Repeatable Read — guarantees that data read in a transaction will not change until it completes, preventing non-repeatable reads, but phantom reads are possible.
• Serializable — the strictest level, transactions execute as if sequentially, preventing all types of anomalies, including phantom reads.

In Go, when working with databases via database/sql, you can manage the isolation level through driver settings or SQL queries, for example, SET TRANSACTION ISOLATION LEVEL.