On Tue, Feb 10, 2015 at 10:26 AM, Sage Weil <sweil@xxxxxxxxxx> wrote: > On Tue, 10 Feb 2015, Somnath Roy wrote: >> Thanks Sam ! >> So, is it safe to do ordering if in a transaction *no* remove/truncate/create/add call ? >> For example, do we need to preserve ordering in case of the below transaction ? >> It will be helpful if you can give some insight in what scenario preserving order is *must*. > > If I'm not mistaken teh only time ordering would matter at all in an > transaction is when the same key is updated twice, right? The whole thing > is committed atomically. If there *are* dups, then the order there > obviously should be preserved. > > Maybe a first pass would be add an assert or something that there are no > dup keys and see if anything every falls out of that... hopefully there > are none! I'm pretty sure some of the transaction analysis discussions people have had say that we do double-updates at times. IIRC it might have been the pglog head getting set twice in most transactions? -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
