Do database transactions prevent race conditions?

Question

It\'s not entirely clear to me what transactions in database systems do. I know they can be used to rollback a list of updates completely (e.g. deduct money on one account a

Answer 1

It depends on the specific rdbms. Generally, transactions acquire locks as decided during the query evaluation plan. Some can request table level locks, other column level, other record level, the second is preferred for performance. The short answer to your question is yes.

In other words, a transaction is meant to group a set of queries and represent them as an atomic operation. If the operation fails the changes are rolledback. I don't exactly know what the adapter you're using does, but if it conforms to the definition of transactions you should be fine.

While this guarantees prevention of race conditions, it doesn't explicitly prevent starvation or deadlocks. The transaction lock manager is in charge of that. Table locks are sometime used, but they come with a hefty price of reducing the number of concurrent operations.