Hi, On 2020-06-04 08:10:07 +0530, Amit Kapila wrote: > On Thu, Jun 4, 2020 at 12:09 AM Andres Freund <and...@anarazel.de> wrote: > > > I strongly disagree with the idea of "just sync(ing) it up at the end > > > of parallelism". That seems like a completely unprincipled approach to > > > the problem. Either the command counter increment is important or it's > > > not. If it's not important, maybe we can arrange to skip it in the > > > first place. If it is important, then it's probably not OK for each > > > backend to be doing it separately. > > > > That scares me too. These command counter increments definitely aren't > > unnecessary in the general case. > > > > Yeah, this is what we want to understand? Can you explain how they > are useful here? AFAIU, heap_lock_tuple doesn't use commandid while > storing the transaction information of xact while locking the tuple.
But the HeapTupleSatisfiesUpdate() call does use it? And even if that weren't an issue, I don't see how it's defensible to just randomly break the the commandid coherency for parallel copy. Greetings, Andres Freund
