[einhverfr]

"This is a good verifiable point? I remember using MySQL cluster when it first shipped. That was a disaster. I also remember using MySQL from a .NET project and opened up a good 3-4 separate bugs about concurrency issues where you could easily deadlock a thread trying to pull a connection from the connection pool."

You can STILL deadlock a transaction against itself in MySQL w/Innodb. How do they let this happen? I do not know. I just know I have been bitten by deadlocks in multi-row inserts quite often there enough to get really really frustrated when I use that db. This is in fact documented in the MySQL manual.

For better or worse, projects which start out without a goal to offer highly reliable software from the start never seem to be able to offer it later.

[latch]

I've also seen a lot of SQL Server developers write large stored procedures that manage to easily deadlock. It's been years since I dealt with it...had something to do with lock escalation, from a read lock to an update lock to an insert lock.

You could say "don't use SQL Server"..or you could say "it's important that you understand SQL Server's locking behavior"

[einhverfr]

It's one thing for two transactions to deadlock against eachother. It takes special talent to allow a transaction to deadlock against itself, which InnoDB apparently allows.

I have NEVER had issues with PostgreSQL transactions deadlocking against themselves, even with monstrous stored procedures.