On Sun, Sep 10, 2017 at 8:47 AM, Amit Kapila <amit.kapil...@gmail.com> wrote:
> On Fri, Sep 8, 2017 at 4:51 PM, amul sul <sula...@gmail.com> wrote: > > On Thu, May 18, 2017 at 9:13 AM, Amit Kapila <amit.kapil...@gmail.com> > > wrote: > >> > >> On Wed, May 17, 2017 at 5:17 PM, Robert Haas <robertmh...@gmail.com> > >> wrote: > >> > On Wed, May 17, 2017 at 6:29 AM, Amit Kapila <amit.kapil...@gmail.com > > > >> > wrote: > >> >> I think we can do this even without using an additional infomask bit. > >> >> As suggested by Greg up thread, we can set InvalidBlockId in ctid to > >> >> indicate such an update. > >> > > >> > Hmm. How would that work? > >> > > >> > >> We can pass a flag say row_moved (or require_row_movement) to > >> heap_delete which will in turn set InvalidBlockId in ctid instead of > >> setting it to self. Then the ExecUpdate needs to check for the same > >> and return an error when heap_update is not successful (result != > >> HeapTupleMayBeUpdated). Can you explain what difficulty are you > >> envisioning? > >> > > > > Attaching WIP patch incorporates the above logic, although I am yet to > check > > all the code for places which might be using ip_blkid. I have got a > small > > query here, > > do we need an error on HeapTupleSelfUpdated case as well? > > > > No, because that case is anyway a no-op (or error depending on whether > is updated/deleted by same command or later command). Basically, even > if the row wouldn't have been moved to another partition, we would not > have allowed the command to proceed with the update. This handling is > to make commands fail rather than a no-op where otherwise (when the > tuple is not moved to another partition) the command would have > succeeded. > > Thank you. I've rebased patch against Amit Khandekar's latest patch (v17_rebased_2) . Also added ip_blkid validation check in heap_get_latest_tid(), rewrite_heap_tuple() & rewrite_heap_tuple() function, because only ItemPointerEquals() check is no longer sufficient after this patch. Regards, Amul
0002-invalidate_ctid-ip_blkid-WIP_2.patch
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