On Thu, Mar 3, 2016 at 6:58 PM, lannis wrote:
> So in the replay scenario, before we read the page from wal segment file,
> using the specical RecPtr which point to the next page header address, can
> we predicat the page header is a long or short?
I am not sure I am getting what you are looking
Thanks for your reply.
If we only take replay for consideration, yeah, we do this header check
until we've read the page first.
But thanks to the master xlog generator, we know that:
when we try advance XLOG insert buffer (page), we treate the new page header
as short header at first.
then we use
On Wed, Mar 2, 2016 at 4:25 PM, wcting wrote:
> /*
> * If at page start, we must skip over the page header. But
> we can't
> * do that until we've read in the page, since the header
> size is
> * variable.
> */
>
> i don't know t
/*
* If at page start, we must skip over the page header. But
we can't
* do that until we've read in the page, since the header
size is
* variable.
*/
i don't know the meaning behind this comments,
if ((RecPtr->xrecoff % X