Re: Do CustomScan as not projection capable node

2019-04-22 Thread Tom Lane
Andrey Lepikhov writes: > It is possible that custom_scan_tlist is designed too nontrivially, and > it is possible that it needs some comments describing in more detail how > to use it. I totally buy the argument that the custom scan stuff is underdocumented :-(. FWIW, if we did have a use-cas

Re: Do CustomScan as not projection capable node

2019-04-22 Thread Andrey Lepikhov
On 22/04/2019 18:40, Robert Haas wrote: On Fri, Apr 19, 2019 at 12:45 AM Tom Lane wrote: I don't buy this for a minute. Where do you think projection is going to happen? There isn't any existing node type that *couldn't* support projection if we insisted that that be done across-the-board.

Re: Do CustomScan as not projection capable node

2019-04-22 Thread Robert Haas
On Fri, Apr 19, 2019 at 12:45 AM Tom Lane wrote: > I don't buy this for a minute. Where do you think projection is > going to happen? There isn't any existing node type that *couldn't* > support projection if we insisted that that be done across-the-board. > I think it's mostly just a legacy thi

Re: Do CustomScan as not projection capable node

2019-04-18 Thread Tom Lane
Andrey Lepikhov writes: > Can we include the CustomScan node in the list of nodes that do not > support projection? That seems like a pretty bad idea. Maybe it's a good thing for whatever unspecified extension you have in mind right now, but it's likely to be a net negative for many more. As a