Re: Quick-and-dirty compression for WAL backup blocks

Tom Lane wrote:

>>>>In the XLogInsert(), it makes two kinds of logs, "whole buffer(page)
>>>>log" and "partial buffer log", isn't it? Is it only "who buffer
>>>>log"
>>>>to generate a log with "hole"?
>
>>
>> Right.

I see.
I think, it is important to reduce the necessities to write whole pages
to WAL (as TODO list).
# It seems difficult to do so... Compressing WAL is easier way.

>> No, because the WAL code cannot assume that all pages follow the
>> convention that pd_lower and pd_upper represent the boundaries of
>> free space. (As a counterexample: index metapages don't always
>> do that.)

Oh, I forget it.
And I think it is good idea to modify XLogInsert API as CVS, too.

--
Junji Teramoto