On 16 Dec 2018, at 2:54pm, Wout Mertens <wout.mert...@gmail.com> wrote:
> imagine having to handle the Zimbabwean Dollar, which ended up having 100 > trillion dollar notes. Good way to overflow your integers. Indeed. But when the crisis started in the early 2000s, the currency was devalued by 1000. Then ten zeros were wiped out at a stroke. And then another twelve zeros were slashed to make the "fourth Zimbabwe dollar". So if you were going to keep track of an account with Z$1 old and Z$1 new you'd need a precision capable of keeping track through 3+10+12 = 25 zeros, or amounts like 10,000,000,000,000,000,000,000,001 The precision of double-precision floats, 52-bit significand, is 2^52 = 4.5e15. Just to store one new Z$. If someone has ten new dollars in their account you could no longer keep their account even in double-precision floating point. You would have needed quad-precision (2^112 = 5.2e33), and banks weren't using that at the time even to do calculations. (I don't know what they use now, I'm not in the industry.) Didn't matter, anyway, since Zim banks just agreed to truncate amounts less than newZ$0.01 . Simon. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
