On Wed, 5 Jun 2019 at 17:14, Rafia Sabih <rafia.pghack...@gmail.com> wrote:
> Regarding this, I came across this, > /* > * Incremental sort can't be used with either EXEC_FLAG_REWIND, > * EXEC_FLAG_BACKWARD or EXEC_FLAG_MARK, because we hold only current > * bucket in tuplesortstate. > */ > I think that is quite understandable. How are you planning to support > backwards scan for this? In other words, when will incremental sort be > useful for backward scan. > We stopped materializing the sort by default about 15 years ago because it wasn't a common use case and it was very expensive for large sorts. It's no real problem if incremental sorts don't support backwards scans - we just won't use incremental in that case. -- Simon Riggs http://www.2ndQuadrant.com/ <http://www.2ndquadrant.com/> PostgreSQL Solutions for the Enterprise
