Re: WIP: Pg_upgrade - page layout converter (PLC) hook - Mailing list pgsql-hackers

Zdenek Kotala napsal(a):

<snip>

> How it works:
> 
> When PLC module is loaded, then for each page which does not have native 
> page version conversion routine is called. Buffer is mark as a dirty and 
> upgraded page is inserted into WAL.
> 

Unfortunately, this approach does not work between layout 3 and 4. It works only 
for heap on platfrom with maxallign=4.

The main problem is that PageHeader has been extended to 24 bytes and it 
requires reindexing, TOAST chunk resizing, converted tuples does not fit on page 
on platform where maxallign=8.

I'm now working on offline conversion method.
    Zdenek