On Wed, Jul 10, 2019 at 12:40 AM Michael Paquier <michael@paquier.xyz> wrote:
On Wed, Jul 10, 2019 at 12:51:28PM +0530, Amit Kapila wrote: > It would be good if we can come up with something like that. It will > be helpful for zheap, where in some cases we get different row > ordering due to in-place updates. As of now, we try to add Order By > or do some extra magic to get consistent row ordering.
That was an issue for me as well when working with Postgres-XC when the row ordering was not guaranteed depending on the number of nodes (speaking of which Greenplum has the same issues, no?). Adding ORDER BY clauses to a set of tests may make sense, but then this may impact the plans generated for some of them.. -- Michael
We have a tool that does this. gpdiff [1] is used for results post-processing and it uses a perl module called atmsort [2] to deal with the specific ORDER BY case discussed here.