FoundationDB/sql-layer — pull request #1086 by nathanlws (2013-12-06 15:27:56+00:00)
Title: Disable concurrent DML by default

The new error returned (attempts to) makes it clear that it is a configuration option. The hope is that it's both reusable, for the handful of other disabled features, but clear enough to have a user ask us how to turn it on.