feat(gcp_storage_object): add prefix filter to storage object list

[villers]

add prefix filter to storage object list

Integration test logs

Logs

select
    name
from
    gcp_storage_object
where
    bucket = 'cdn-signature' and
    prefix = 'prefix'

Example query results

Results

prefix/items1.txt
prefix/items2.txt

[jplanckeel]

❓ question : Why you need prefix in key column ?

[villers]

The "prefix" in the key columns is added as an optional parameter, meaning it's not required for the function to operate, but if it's provided, it can be used to narrow down the returned results based on the prefix of the object keys in the Google Cloud Storage bucket.

As for the "prefix" field in the table definition, it's a pseudo-column. This means it doesn't actually exist in the Google Cloud Storage Object data, but it is used to provide an additional filter (the prefix in this case) when querying the table. The transform.FromQual("prefix") is used to take the value from the query qualifier and add it to the request. This way, it's possible to write a query like select * from gcp_storage_object where prefix = 'your-prefix', and the results would be only the objects that have keys starting with 'your-prefix'.

[rajlearner17]

@villers Thanks for this PR. Adding an example for this using a prefix column will be suitable for the user. Thank you!

[villers]

@villers Thanks for this PR. Adding an example for this using a prefix column will be suitable for the user. Thank you!

it's done

[cbruno10]

@villers Thanks so much for the contribution!