Store tables per default as parquet files

[hagenw]

As we now support storing tables as parquet files in audb>=1.8.0, and have published the first databases, I would propose to switch to parquet for storing tables in the next audformat release.

This pull request changes the default values of the storage_format argument in audformat.Database.save() and audformat.Table.save() to "parquet".

[hagenw]

Seems our tests were already well prepared for this step, as I didn't had to change anything.

[ChristianGeng]

This basically changes the derfault table storage format to the newer parquet in two locations:

• the datatabase level
• at the level of the table

I do not know where the Table.save is used other than by Database.save so I cannot judge whether this is functionally necessary: grepping the source code of this repo and the audb repo suggests that this is never done.

So my understanding is that one could get away without defaulting to parquet in Table - still it is better at the level of API consistency.

I will approve this right away.

[hagenw]

So my understanding is that one could get away without defaulting to parquet in Table - still it is better at the level of API consistency.

Exactly, we don't have to change it in audformat.Table.save(), but I also thought that it would be more consistent this way.