Re: XLByte* usage

On Mon, Dec 17, 2012 at 11:17 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> writes:
>> On 17.12.2012 11:04, Pavan Deolasee wrote:
>>> On Mon, Dec 17, 2012 at 2:00 PM, Heikki Linnakangas
>>> <hlinnakangas(at)vmware(dot)com> wrote:
>>>> I've still used XLByte* macros, but I agree that plain <=> are easier to
>>>> read. +1 for using <=> in new code.
>
>>> Do we ever see us changing this from 64-bit integers to something else
>>> ? If so, a macro would be much better.
>
>> I don't see us changing it again any time soon. Maybe in 20 years time
>> people will start overflowing 2^64 bytes of WAL generated in the
>> lifetime of a database, but I don't think we need to start preparing for
>> that yet.
>
> Note that to get to 2^64 in twenty years, an installation would have had
> to have generated an average of 29GB of WAL per second, 24x7 for the
> entire twenty years, with never a dump-and-reload. We're still a few
> orders of magnitude away from needing to think about this.
>

I probably did not mean increasing that to beyond 64-bit. OTOH I
wondered if we would ever want to steal a few bits from the LSN field,
given the numbers you just put out. But it was more of a question than
objection.

Thanks,
Pavan

--
Pavan Deolasee
http://www.linkedin.com/in/pavandeolasee