Imported from https://www.w3.org/Bugs/Public/show_bug.cgi?id=11528

Based on lots of developer feedback, in addition to the current automatic commit model it would be nice to support:

• explicitly committing, to avoid extra round-trips (known performance bottleneck)
• ways to defer committing to allow other async processing to occur within transaction scope

Both make the transaction model more complex, so we should tread carefully.