On Thu, Mar 9, 2017 at 11:50 AM, Dilip Kumar <dilipbalaut@gmail.com> wrote: > On Thu, Mar 9, 2017 at 10:02 PM, Dilip Kumar <dilipbalaut@gmail.com> wrote: >> I slightly modified your query to reproduce this issue. >> >> explain analyze select * from r1 where value<555; >> >> Patch is attached to fix the problem. > > I forgot to mention the cause of the problem. > > if (istate->schunkptr < istate->nchunks) > { > PagetableEntry *chunk = &ptbase[idxchunks[istate->schunkptr]]; > PagetableEntry *page = &ptbase[idxpages[istate->spageptr]]; > BlockNumber chunk_blockno; > > In above if condition we have only checked istate->schunkptr < > istate->nchunks that means we have some chunk left so we are safe to > access idxchunks, But just after that we are accessing > ptbase[idxpages[istate->spageptr]] without checking that accessing > idxpages is safe or not. > > tbm_iterator already handling this case, I broke it in tbm_shared_iterator.
I don't know if this is the only problem -- it would be good if David could retest -- but it's certainly *a* problem, so committed.
Thanks for committing, and generally parallelising more stuff.
I confirm that my test case is now working again.
I'll be in this general area today, so will mention if I stumble over anything that looks broken.
