Re: Questions about update, delete, ctid...

Hello Tom, Martijn and List,

Thank you for yours answers !
This point is now closed for me and I can go further in the mecanisms of
VACUUM.

Regards,
Alexandra

Tom Lane wrote:

>DANTE Alexandra <Alexandra(dot)Dante(at)bull(dot)net> writes:
>
>
>> - during a SELECT query on a tuple just updated and commited, does
>>the executor first detect the old tuple and then via the c_tid link go
>>to the new version of the tuple ? or go directly to the new version ?
>>
>>
>
>Neither. SELECT doesn't care about update relationships, it just
>returns whatever row version is current according to its snapshot.
>It's only UPDATE/DELETE that are constrained to act on the most
>current version of each row.
>
> regards, tom lane
>
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