Kas saaksite loetleda PostgreSQL-is kasutatavate tehingu isolatsiooni taseme tüüpe?

PostgreSQL supports four standard transaction isolation levels, defined in the SQL standard:

1. Read Uncommitted — the lowest level, allows reading data that has not yet been committed (dirty reads). In PostgreSQL, it actually behaves like Read Committed.
2. Read Committed — the transaction sees only data that was committed at the start of the query. This is the default level in PostgreSQL.
3. Repeatable Read — the transaction sees data as it was at the start, preventing non-repeatable reads.
4. Serializable — the strictest level, ensures full isolation of transactions, as if they were executed sequentially.

Example of setting the isolation level in SQL:

BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
-- your operations
COMMIT;