Just for your information. I tried to implement "float2" according to IEEE 754 specification, as a custom data type of PG-Strom.
https://github.com/heterodb/pg-strom/blob/master/src/float2.c https://github.com/heterodb/pg-strom/blob/master/sql/float2.sql The recent GPU device (Maxwell or later) supports "half" precision data type by the hardware, so it might be valuable for somebody. Thanks, 2017-11-14 14:49 GMT+09:00 Kohei KaiGai <kai...@heterodb.com>: > 2017-11-14 10:33 GMT+09:00 Thomas Munro <thomas.mu...@enterprisedb.com>: >> On Tue, Nov 14, 2017 at 1:11 PM, Kohei KaiGai <kai...@heterodb.com> wrote: >>> Any opinions? >> >> The only reason I can think of for having it in core is that you might >> want to use standard SQL notation FLOAT(10) to refer to it. Right now >> our parser converts that to float4 but it could map precisions up to >> 10 to float2. The need for such special treatment is one of my >> arguments for considering SQL:2016 DECFLOAT(n) in core PostgreSQL. >> But this case is different: FLOAT(10) already works, it just maps to a >> type with a larger significand, as permitted by the standard. So why >> not just do these short floats as an extension type? >> > Our extension will be able to provide its own "half" or "float2" data type > using CREATE TYPE, indeed. I thought it is useful to other people, even > if they are not interested in the in-database analytics with GPU, to reduce > amount of storage consumption. > > Of course, it is my opinion. > > Thanks, > -- > HeteroDB, Inc / The PG-Strom Project > KaiGai Kohei <kai...@heterodb.com> -- HeteroDB, Inc / The PG-Strom Project KaiGai Kohei <kai...@heterodb.com>
