Database deadlocks

Question

One of the classical reasons we have a database deadlock is when two transactions are inserting and updating tables in a different order.

For example, transaction A

Answer 1

I analyze all database actions to determine, for each one, if it needs to be in a multiple statement transaction, and then for each such case, what the minimum isolation level is required to prevent deadlocks... As you said serializable will certainly do so...

Generally, only a very few database actions require a multiple statement transaction in the first place, and of those, only a few require serializable isolation to eliminate deadlocks.

For those that do, set the isolation level for that transaction before you begin, and reset it whatever your default is after it commits.