I’m +1 on reverting it. Let’s not change around functionality on our users and let’s stay as close as possible to the standard, both of which reverting this seems to do.
Alan. > On Jun 10, 2016, at 16:07, Sergey Shelukhin <ser...@hortonworks.com> wrote: > > There has recently been a change in behavior in Hive wrt doubles and > decimals, HIVE-13380; where the literals were changed to be double by > default, resulting in some unexpected behavior when comparing decimal > columns with arithmetic expressions on literals. > Right now it has been reverted from 2.1, it’s still there on master until > we decide what to do. > > According to SQL92 (I don’t have access to a later one), section 5.3 > <exact numeric literal> ::= <unsigned integer> [ <period> [ <unsigned > integer> ] ] | <period> <unsigned integer> > ... > 13)The data type of an <exact numeric literal> is exact numeric. > > From previous comments there, exact-numeric would basically be decimal in > this case. > > Approximate (basically, float/double in this case) literal is defined as > <approximate numeric literal> ::= <mantissa> E <exponent> > > Then, in 6.12, the expression (at least the arithmetic) on two exacts > needs to have the exact results; if either side is approximate, the result > is approximate. > > However, some RDBMS-es apparently prefer double over decimal. > > I think we should go according to SQL92, revert the patch also from > master, and also potentially investigate ANSI SQL compatibility for > existing type resolution in other places. > Opinions, suggestions, comments? > > > >
