Re: Extract numeric filed in JSONB more effectively

a) effectiveness. The ending performance should be similar like your current patch, but without necessity to use planner support API.

 

So the cost is we need to create a new & different framework.  

 

b) because you can write only var := j->'f', and plpgsql forces cast function execution, but not via planner.

 

var a := 1 needs going with planner,  IIUC,  same with j->'f'.  

c) nothing else. It should not to require to modify cast function definitions

 

If you look at how the planner support function works,  that is

pretty simple,  just modify the prosupport attribute. I'm not sure

this should be called an issue or avoiding it can be described

as a benefit. 

I don't think the current case is as bad as the other ones like

users needing to modify their queries or type-safety system

being broken. So personally I'm not willing to creating some

thing new & heavy. However I'm open to see what others say.  

 

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Best Regards

Andy Fan