From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Peter Geoghegan <pg(at)bowt(dot)ie>, Andres Freund <andres(at)anarazel(dot)de>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>, Anastasia Lubennikova <a(dot)lubennikova(at)postgrespro(dot)ru> |
Subject: | Re: Allow to specify #columns in heap/index_form_tuple |
Date: | 2017-03-31 19:03:55 |
Message-ID: | 14063.1490987035@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Fri, Mar 31, 2017 at 2:32 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> It just seems way too dangerous.
> So, we end up with heap tuples with different numbers of attributes
> all the time, whenever you add a column. It works fine - on decoding,
> the additional columns will be treated as null (unless somebody
> commits Serge Rielau's patch, which regrettably nobody has gotten
> around to reviewing). Why is this case different?
The reason it works fine for heap tuples is that heap tuple headers
explicitly record the number of attributes in the tuple. Index
tuples don't.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Jeff Janes | 2017-03-31 19:09:15 | Re: Patch: Write Amplification Reduction Method (WARM) |
Previous Message | Brandur Leach | 2017-03-31 19:03:18 | Re: [PATCH] SortSupport for macaddr type |