[postgis-devel] Inconsistencies in text output

[Martin Davis]

On Fri, Apr 17, 2020 at 9:35 AM <rmrodriguez at carto.com> wrote:

>
> I wanted a way to ensure there would be no loss of information when
> doing storage1 > wkt/geojson -> storage2 as not having this has caused
> issues where the stored geometry was valid, but after moving it using
> GeoJSON it wasn't valid anymore.
> The solution option there was to ask for more resolution, but since
> the function isn't working as announced I wouldn't get it.  Yes,
> ideally the end system should be able to read WKB, but that's not
> always the case.
>

So if you specify say 20 decimal digits, you aren't getting them?  It seems
like this at least should be made to work.  It doesn't sound like a bad
thing, as long as it doesn't cause *unspecified* precision output to get a
lot longer.

I'm wondering whether it is actually possible to have no-loss
round-tripping with binary -> text -> binary?  And if so, how many digits
are required to guarantee this?

I know it's not possible to round-trip text -> binary -> text, since there
are decimal numbers which aren't finitely representable in binary (e.g
1.3).
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