Re: [HACKERS] Possible problem in Custom Scan API - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] Possible problem in Custom Scan API
Date
Msg-id 20021.1491933424@sss.pgh.pa.us
Whole thread Raw
In response to [HACKERS] Possible problem in Custom Scan API  (Dmitry Ivanov <d.ivanov@postgrespro.ru>)
Responses Re: [HACKERS] Possible problem in Custom Scan API  (Dmitry Ivanov <d.ivanov@postgrespro.ru>)
List pgsql-hackers
Dmitry Ivanov <d.ivanov@postgrespro.ru> writes:
> In theory, CustomScans should be able to use any Plan nodes (i.e. 
> 'custom_plans' list), but as far as I can understand, there's no way to 
> override behavior of use_physical_tlist(), which means that we might see 
> something like this:

> ERROR:  variable not found in subplan target list

> if we use child IndexOnlyScan and the index does not include some of the 
> relation's columns.

Uh, why would you see that?  The planner would never generate an
IndexOnlyScan in the first place if the query required any columns
not available from the index.
        regards, tom lane



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