Sorry, I forgot to write more significant thing.
On 2020/02/06 21:22, Kyotaro Horiguchi wrote:
At Thu, 6 Feb 2020 11:57:07 +0100, Dmitry Dolgov <9erthali...@gmail.com> wrote
in
On Thu, Feb 06, 2020 at 10:24:50AM +0900, Kyotaro Horiguchi wrote:
At Wed, 5 Feb 2020 17:37:30 +0100, Dmitry Dolgov <9erthali...@gmail.com> wrote
in
We could add an additional parameter "in_cursor" to
ExecSupportBackwardScan and let skip scan return false if in_cursor is
true, but I'm not sure it's acceptable.
I also was thinking about whether it's possible to use
ExecSupportBackwardScan here, but skip scan is just a mode of an
index/indexonly scan. Which means that ExecSupportBackwardScan also need
to know somehow if this mode is being used, and then, since this
function is called after it's already decided to use skip scan in the
resulting plan, somehow correct the plan (exclude skipping and try to
find next best path?) - do I understand your suggestion correct?
No. I thought of the opposite thing. I meant that
IndexSupportsBackwardScan returns false if Index(Only)Scan is
going to do skip scan. But I found that the function doesn't have
access to plan node nor executor node. So I wrote as the follows.
I didn't thought so hardly, but a bit of confirmation told me that
IndexSupportsBackwardScan returns fixed flag for AM. It seems that
things are not that simple.
regards.
--
Kyotaro Horiguchi
