On Aug 30, 2013, at 11:49 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> Even better explanation: The merge append is some steps below a LockRows
> node, so the number of rescans might depend on the concurrency because
> we'll do the EvalPlanQual dance on a concurrent row update.
>
> Terje, do you use read committed or repeatable read/serializable?
Using Read Committed.
Terje