Re: why does txid_current() assign new transaction-id?

On Wed, May 27, 2015 at 5:13 PM, Naoya Anzai <nao-anzai(at)xc(dot)jp(dot)nec(dot)com> wrote:
>> Perhaps we could make the documentation
>> clearer about those things though, changing the description of this
>> function to "get current transaction ID, and assign a new one if one
>> is not assigned yet":
>> http://www.postgresql.org/docs/devel/static/functions-info.html
> +1
>
> I think that a description of txid_current is too rough and it might
> be confused some users.
> txid_current is a different operation depending on session situations,
> I feel if detail of txid_current is documented then it will be better.
>
> For example...
> Inside of the transaction-block(begin..end), returns a transaction-id used by this block.
> Outside of the transaction-block, returns a next transaction-id(but it is consumed by this function).

Attached is a doc patch among those lines.
--
Michael