Rationalize all db command output text

[timriley]

Right now it all feels a bit noisy as well as inconsistent. Maybe pare it back a little and keep it simple. Perhaps avoid using the measure block for most of these, since the timing doesn't feel that important, and measure's handling of failures results in confusing back-to-front text ordering (i.e. the specific error messages first, and then the summary of the command that failed underneath it).