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