[postgis-devel] Validity flag

Sandro Santilli strk at keybit.net
Mon Feb 29 08:34:47 PST 2016

On Mon, Feb 29, 2016 at 02:01:39PM +0100, Hugo Mercier wrote:

> The first bit in the byte is now documented as "Version". What does it
> mean ? It is precisely to mark it as a future "extended" version ?

By documented you mean in liblwgeom/g_serialized.txt ?

There I see:

  uchar flags; /* Version, Validity, Solid, ReadOnly, IsGeodetic, HasZ, HasM, HasBBox */

It would be helpful to expand that documentation more,
if it is all we have .

I believe "Version" was just made up in Paris, I didn't partecipate
to that discussion and think it could be re-started here.

My feeling is that one of the bits should be used as an "extend" bit,
bringing in another byte (or more) of flags.

Besides, I don't think the "ReadOnly" flag belongs in the serialized
format at all (would make no sense there!).

So I'd first of all ask everyone: is g_serialized.txt our most
complete document on the format ? Is it _correct_ ?


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