Re: CURRENT OF causes an error when IndexOnlyScan is used - Mailing list pgsql-hackers

From Tom Lane
Subject Re: CURRENT OF causes an error when IndexOnlyScan is used
Date
Msg-id 22958.1517451171@sss.pgh.pa.us
Whole thread Raw
In response to Re: CURRENT OF causes an error when IndexOnlyScan is used  (Yugo Nagata <nagata@sraoss.co.jp>)
Responses Re: CURRENT OF causes an error when IndexOnlyScan is used
Re: CURRENT OF causes an error when IndexOnlyScan is used
List pgsql-hackers
Yugo Nagata <nagata@sraoss.co.jp> writes:
> I'm sorry the patch attached in the previous mail is broken and
> not raises a compile error. I attached the fixed patch.

This patch is almost certainly wrong: you can't assume that the scan-level
state matches the tuple we are currently processing at top level.  Any
sort of delaying action, for instance a sort or materialize node in
between, would break it.

We need to either fix this aspect:

>> IndexOnlyScan returns a virtual tuple that doesn't have system
>> column, so we can not get ctid in the same way of other plans.

or else disallow using IndexOnlyScan when the ctid is needed.

            regards, tom lane


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