Replace backend options by something else

xref #2593 xref https://github.com/ibis-project/ibis/pull/2379#issuecomment-785510513

At the moment, this is valid Ibis valid code:

import ibis

ibis.options.impala.temp_db = 'foo'

client = ibis.impala.connect(...)

Ideally, we would like load a backend only if it’s used (on ibis.impala.connect). But the code ibis.options.impala.temp_db = 'foo' would fail if the backend has not yet been loaded. So, we are currently loading all backends on startup (skipping the ones raising ImportError).

Personally, I think what makes more sense is that backends can’t implement global options, but they use connection parameters. With a unified connect function (see #2532), it could look like this (it could also be implemented if we don’t unify connect):

conn = ibis.connect('impala://user@impala/ibis_testing',
                    temp_db='foo')

There are probably other options, like making options load backends, adding a .set_option to the client… But I think the one above is clearer.

[datapythonista]

Do you think I should move forward with removing the option in ibis-project/ibis-bigquery#37?

Personally, I think the best for users would be using ibis.connect(connection_string) (see #2532). Not sure if when you mean ibis_bigquery.connect you mean Backend.connect. But yes, I think it’s a good idea to make partition_col a connect parameter instead of an ibis option.

[cpcloud]

It would be great to see what this would look like in a PR, but we can’t keep the issue open forever.