Re: Snapshot synchronization, again...

Peter Eisentraut <peter_e@gmx.net> writes:
> On fre, 2011-02-18 at 16:57 -0300, Alvaro Herrera wrote:
>> 2. is md5 the most appropriate digest for this?  If you need a
>> cryptographically secure hash, do we need something stronger?  If not,
>> why not just use hash_any?

> MD5 is probably more appropriate than hash_any, because the latter is
> optimized for speed and collision avoidance and doesn't have a
> guaranteed external format.  The only consideration against MD5 might be
> that it would make us look quite lame.

Only to people who don't understand whether crypto strength is actually
important in a given use-case.

However ... IIRC, hash_any gives different results on bigendian and
littleendian machines.  I'm not sure if a predictable cross-platform
result is important for this use?  If you're hashing data containing
native integers, this is a problem anyway.
        regards, tom lane