Hi Mike,
Is this a C++ question?
Optional in the schema means it can be null/missing. It usually translate
into the definition level being 0 (null) or 1 (defined) which is also how
it is represented in an Arrow validity vector.
Definition levels explanation here:
https://blog.twitter.com/2013/dremel-made-simple-with-parquet


On Mon, May 15, 2017 at 7:39 AM, Katelman, Michael <
[email protected]> wrote:

> Hi,
>
> I was wondering if someone could help me understand what  the correct way
> is to represent and write out NA values using a TypedColumnWriter.
> Basically, what I want to do is, e.g., repeatedly write out batches of
> doubles where some of them may arbitrarily be None's. It seemed like maybe
> some combination of OPTIONAL, definition levels, and valid bits might work,
> but it wasn't exactly clear to me. So, if someone could point me in the
> right direction I would appreciate it.
>
> -Mike
>
>
>
>
>
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-- 
Julien

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