Re: Quick question regarding HeapTupleHeaderData.t_ctid

Aleksander Alekseev <aleksander@timescale.com> writes:
> So t_ctid will point to the newer version of the tuple regardless of
> whether HOT is used or not. But I couldn't find an answer to how
> t_ctid is used when a tuple is not a part of a HOT chain, or is the
> last item in the chain.

t_ctid points to the tuple itself if it's the latest version of its row.

> Which brings a question, maybe it shouldn't
> take that much space on disk.

How would you make it optional?  In particular, what are you going to
to when it's time to update a row (and therefore insert a ctid link)
and the page is already completely full?

            regards, tom lane