Re: Allow to specify #columns in heap/index_form_tuple

On Fri, Mar 31, 2017 at 1:44 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Andres Freund <andres@anarazel.de> writes:
>> The covering indexes patch [1] really needs a version of
>> heap_form_tuple/index_form_tuple that allows to specify the number of
>> columns in the to-be generated tuple.
>
> I was thinking about that this morning, and wondering why exactly it
> would need such a thing.  Certainly we're not going to store such a
> truncated tuple in the index, ...

The patch stores it in the index as a high key.

You might want to have a read through that patch.  I think your
opinion would be helpful in determining how close that patch is to
being ready to commit (same for WARM).

-- 
Robert Haas
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