Re: [HACKERS] Bugs in our qsort implementation

2015-07-16 Thread Tom Lane
Peter Geoghegan writes: > On Thu, Jul 16, 2015 at 5:05 PM, Tom Lane wrote: >> It's possible that this issue can only manifest on 9.4 and up where >> we have the ability for tuplesort to allocate work arrays approaching >> INT_MAX elements. But I don't have a lot of faith in that; I think the >>

Re: [HACKERS] Bugs in our qsort implementation

2015-07-16 Thread Peter Geoghegan
On Thu, Jul 16, 2015 at 5:05 PM, Tom Lane wrote: > It's possible that this issue can only manifest on 9.4 and up where > we have the ability for tuplesort to allocate work arrays approaching > INT_MAX elements. But I don't have a lot of faith in that; I think the > worst-case stack depth for the

[HACKERS] Bugs in our qsort implementation

2015-07-16 Thread Tom Lane
I've been trying to figure out the crash in qsort reported here: http://www.postgresql.org/message-id/flat/cal8hzunr2fr1owzhwg-p64gjtnfbbmpx1y2oxmj_xuq3p8y...@mail.gmail.com I first noticed that our qsort code uses an int to hold some transient values representing numbers of elements. Since the p