Re: [HACKERS] UPDATE of partition key

On Thu, Jun 8, 2017 at 7:01 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Thu, Jun 8, 2017 at 1:33 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Wed, Jun 7, 2017 at 5:46 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>> As far as I understand, it is to ensure that for deleted rows, nothing
>>> more needs to be done.  For example, see the below check in
>>> ExecUpdate/ExecDelete.
>>> if (!ItemPointerEquals(tupleid, &hufd.ctid))
>>> {
>>> ..
>>> }
>>> ..
>>>
>>> Also a similar check in ExecLockRows.  Now for deleted rows, if the
>>> t_ctid wouldn't point to itself, then in the mentioned functions, we
>>> were not in a position to conclude that the row is deleted.
>>
>> Right, so we would have to find all such checks and change them to use
>> some other method to conclude that the row is deleted.  What method
>> would we use?
>
> I think before doing above check we can simply check if ctid.ip_blkid
> contains InvalidBlockNumber, then return an error.

Hmm, OK.  That case never happens today?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company