Re: [WIP] In-place upgrade

"Robert Haas" <robertmhaas(at)gmail(dot)com> writes:

>> We've talked about this many times before, so I'm sure you know what my
>> opinion is. Let me phrase it one more time:
>>
>> 1. You *will* need a function to convert a page from old format to new
>> format. We do want to get rid of the old format pages eventually, whether
>> it's during VACUUM, whenever a page is read in, or by using an extra
>> utility. And that process needs to online. Please speak up now if you
>> disagree with that.
>
> Well, I just proposed an approach that doesn't work this way, so I
> guess I'll have to put myself in the disagree category, or anyway yet
> to be convinced. As long as you can move individual tuples onto new
> pages, you can eventually empty V3 pages and reinitialize them as new,
> empty V4 pages. You can force that process along via, say, VACUUM,

No, if you can force that process along via some command, whatever it is, then
you're still in the category he described.

--
Gregory Stark
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