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Posted to dev@arrow.apache.org by Fernando Herrera <fe...@gmail.com> on 2021/02/06 11:50:12 UTC

[RUST] Fields and schema metadata

Hi all, Is there a reason why the Field metadata is a BTreeMap and Schema's
metadata is a HashMap?

I'm just curious why different structures were selected for the same thing.
Sorry if this is explained somewhere in the code, but I couldn't find
anything about it.

Fernando,

Re: [RUST] Fields and schema metadata

Posted by Fernando Herrera <fe...@gmail.com>.

I see. I guess you are doing key comparison on the Field's metadata. Thanks
for the clarification

On Sat, Feb 6, 2021 at 12:27 PM Neville Dipale <ne...@gmail.com>
wrote:

> We had to use the BTreeMap because a HashMap doesn't implement Hash, so
> can't be used in the Field.
>
> The easiest way to see this, is to replace it with a HashMap, and try
> compile the arrow crate.
>
> Neville
>
> On Sat, 06 Feb 2021, 13:50 Fernando Herrera, <fernando.j.herrera@gmail.com
> >
> wrote:
>
> > Hi all, Is there a reason why the Field metadata is a BTreeMap and
> Schema's
> > metadata is a HashMap?
> >
> > I'm just curious why different structures were selected for the same
> thing.
> > Sorry if this is explained somewhere in the code, but I couldn't find
> > anything about it.
> >
> > Fernando,
> >
>

Re: [RUST] Fields and schema metadata

Posted by Neville Dipale <ne...@gmail.com>.

We had to use the BTreeMap because a HashMap doesn't implement Hash, so
can't be used in the Field.

The easiest way to see this, is to replace it with a HashMap, and try
compile the arrow crate.

Neville

On Sat, 06 Feb 2021, 13:50 Fernando Herrera, <fe...@gmail.com>
wrote:

> Hi all, Is there a reason why the Field metadata is a BTreeMap and Schema's
> metadata is a HashMap?
>
> I'm just curious why different structures were selected for the same thing.
> Sorry if this is explained somewhere in the code, but I couldn't find
> anything about it.
>
> Fernando,
>