Re: Hot standby and GiST page splits (was Re: WIP: Fast GiST index build)

On Tue, Aug 2, 2011 at 12:43 PM, Heikki Linnakangas
<heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> On 02.08.2011 14:36, Simon Riggs wrote:
>>
>> On Tue, Aug 2, 2011 at 12:03 PM, Heikki Linnakangas
>> <heikki(dot)linnakangas(at)enterprisedb(dot)com>  wrote:
>>>
>>> If we change the WAL record, we have to make it so that the new version
>>> can
>>> still read the old format, which complicates the implementation a bit.
>>> Neverthelss, I'm leaning towards option 1.
>>
>> We may as well do (1), with two versions of the WAL record.
>
> Actually I think we can append the new information to the end of the page
> split record, so that an old version server can read WAL generated by new
> version, too.

Not sure how that would work. Lengths, CRCs?

Or do you mean we will support 2 versions, have them both called the
same thing, just resolve which is which by the record length. Don't
like that.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services