Tom Lane wrote: > Florian Weimer <[EMAIL PROTECTED]> writes: >> Have you tried switching to Adler32 instead of CRC32? > > Is anything known about the error detection capabilities of Adler32? > There's a lot of math behind CRCs but AFAIR Adler's method is pretty > much ad-hoc.
As I understand it, it's kinda well studied; but has known weaknesses in its ability to detect errors under some conditions. Quoting wikipedia: "Adler-32 has a weakness for short messages with few hundred bytes, because the checksums for these messages have a poor coverage of the 32 available bits...Jonathan Stone discovered in 2001 that Adler-32 has a weakness...An extended explanation can be found in RFC 3309, which mandates the use of CRC32 instead of Adler-32...." I'm not sure if I'm kidding or not here, but I wonder if the not uncommon requests on the lists of weakening protective features in postgresql (full-page writes, fsync off, "but mysql says", etc) suggest that a "dont_protect_against_os_or_hardware_failures" mode might be in demand for non-critical / development instances. ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
