* Tom Lane <[EMAIL PROTECTED]> [081118 12:43]: > Aidan Van Dyk <[EMAIL PROTECTED]> writes: > > But why can't you wal-log the hint bits from the "buffered" page. then your > > consitent. At least as consistent as the original write was. > > > So you're CRC ends up being: > > Buffer the page > > Calculate CRC on the buffered page > > WAL (in bulk) the hint bits (and maybe CRC?) > > write buffered page > > The trouble here is to avoid repeated WAL-logging of the same hint bits. > > (Alvaro's patch tried to do that by depending on another hint bit in the > page header, but that seems unsafe if hint bit setters aren't taking > exclusive lock.)
And I know it's extra IO. That's why I started the whole thing with a question along the lines of "how much extra IO are people going to take" for the sake of "guarenteeing" we read exactly what we wrote. a. -- Aidan Van Dyk Create like a god, [EMAIL PROTECTED] command like a king, http://www.highrise.ca/ work like a slave.
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