Upgrade pyarrow

[randyzwitch]

Evaluate whether we can loosen the upper bound of the pyarrow dependency

[randyzwitch]

We do not currently support pyarrow 0.14, as some breaking changes were made between 0.13 and 0.14. Specifically, the following passage could be our issue, which is resolved directly in OmniSciDB:

The dictionary API has been reworked in ARROW-3144. The dictionary values used to be tied to the DictionaryType instance, which ended up too inflexible. Since dictionary-encoding is more often an optimization than a semantic property of the data, we decided to move the dictionary values to the ArrayData structure, making it natural for dictionary-encoded arrays to share the same DataType instance, regardless of the encoding details.

[xhochy]

There is also the 0.15.x series out now.

[randyzwitch]

Thanks @xhochy, we’re evaluating if we can jump right to 0.15

[mikehinchey]

Pymapd now uses pyarrow 0.15.0