Re: FP16 Support?

On 2017-11-13 20:21:47 -0500, Tom Lane wrote:
> Kohei KaiGai <kaigai(at)heterodb(dot)com> writes:
> > How about your thought for support of half-precision floating point,
> > FP16 in short?
>
> This sounds like a whole lotta work for little if any gain. There's not
> going to be any useful performance gain from using half-width floats
> except in an environment where it's the individual FLOPs that dominate
> your costs. PG is not designed for that sort of high-throughput
> number-crunching, and it's not likely to get there anytime soon.
>
> When we can show real workloads where float32 ops are actually the
> dominant time sink, it would be appropriate to think about whether
> float16 is a useful solution. I don't deny that we could get there
> someday, but I think putting in float16 now would be a fine example
> of having your priorities reversed.

Agree that there's no performance argument. I think you could kinda
sorta make an argument for higher storage density in cases where a lot
of floats are stored in the database. I'd personally still consider
that not worthwhile to invest time in, but ...

Greetings,

Andres Freund