Acclerating INSERT/UPDATE using UPS

Hello PostgreSQL Hackers,

I have made a modification of PostgreSQL which accelerates INSERT/UPDATE using UPS. The name of the software is "Sigres", and the philosophy is considering a battery supplied memory as a persistent device instead of a disk. You can download Sigres from http://sourceforge.jp/projects/sigres/ .

In the maximum case, Sigres is 7 times faster than PostgreSQL default (fsync=on) in my environment (CoreDuo 2.66GHz, UDMA/133), and it is also 10% faster than PostgreSQL without fsync (fsync=off).

The magic lies in usually skipping XLogWrite() and ignoring WALWriteLock. The exceptions are XLogWrite() calls from AdvanceXLInsertBuffer(). In addition, in XLogFileClose() issue_xlog_fsync() before close(). (In this point, Sigres is different from just simply setting fsync=off.)

Although I think Sigres can be considered as one of the future directions of PostgreSQL, I do not know whether this software can be accepted or not. Could you please give me some comments ?

Best Regards,

-- Hideyuki Kawashima
Assistant Professor, University of Tsukuba