Minor: Improve ObjectStoreUrl docs + examples

[alamb]

Which issue does this PR close?

related to #10616

Rationale for this change

While working on #10549 I kept getting confused about what an ObjectStoreUrl was / is.

Thus I felt some documentation / examples would help

What changes are included in this PR?

Add more docs + examples

Are these changes tested?

new doc examples

Are there any user-facing changes?

Docs + examples

No functional changes

[goldmedal]

Thanks @alamb LGTM.
This example clearly explains how to use ObjectStoreUrl.

[goldmedal]

On a related note, I found that the usage flow of ObjectStore in DataFusion involves registering the source as a table and then querying the table. This approach makes sense. However, I think it might be possible to provide something like a table function or other methods to allow users to dynamically decide which path they want to scan.

There are similar features in DuckDB and Spark:

• DuckDB: SELECT * FROM read_parquet('file-path/test.parquet')
• Spark: spark.read.parquet('xxxx')

Does DataFusion already have this feature, or did I miss it? If not, I think it would be a valuable feature for users of object storage.

[alamb]

Does DataFusion already have this feature, or did I miss it? If not, I think it would be a valuable feature for users of object storage.

THis feature is in datafusion-cli (not DataFusion core) via a dynamic schema provider

andrewlamb@Andrews-MacBook-Pro-2:~/Software/influxdb_iox$ datafusion-cli
DataFusion CLI v38.0.0
> select * from '/tmp/foo.parquet';
+---------+
| column1 |
+---------+
| 1       |
+---------+
1 row(s) fetched.
Elapsed 0.015 seconds.

Automatically allowing access to reading arbtrary files / urls is likely not appropriate for datafusion by default, however having it be an easier feature to add would be good.

Maybe this would be a good feature to add as an example or maybe even move the dynamic table provider into datafusion core (not enabled by default) if this is a feature others want

[goldmedal]

Maybe this would be a good feature to add as an example or maybe even move the dynamic table provider into datafusion core (not enabled by default) if this is a feature others want

Cool! Thanks for the information!
I think some users may want to use it directly through the core. It's very convenient to build a system that can query object storage dynamically.

[comphead]

lgtm thanks @alamb