Re: [HACKERS] Full page writes improvement, code update

The score below was taken based on 8.2 code, not 8.3 code.  So I don't
think the below measure is introduced only in 8.3 code.

Tom Lane wrote:
> Koichi Suzuki <suzuki.koichi@oss.ntt.co.jp> writes:
>> For more information, when checkpoint interval is one hour, the amount
>> of the archived log size was as follows:
>> cp:             3.1GB
>> gzip:           1.5GB
>> pg_compresslog: 0.3GB
> 
> The notion that 90% of the WAL could be backup blocks even at very long
> checkpoint intervals struck me as excessive, so I went looking for a
> reason, and I may have found one.  There has been a bug in CVS HEAD
> since Feb 8 causing every btree page split record to include a backup
> block whether needed or not.  If these numbers were taken with recent
> 8.3 code, please retest with current HEAD.
> 
> 			regards, tom lane
> 


-- 
Koichi Suzuki