How can I create a cloud function 2nd gen which will be triggered when new entry comes to a table

I would like to create a function which will be triggered when new entry was inserted into a BigQuery table called "staging_tbl".

staging_tbl
A    | B    | C
val1 | val2 | val3

Often new entries will be inserted and I want that everytime when a new entry is inserted into the table, a cloud function is triggered with this entry.

I have a function with the following trigger:

  event_trigger = {
    trigger_region        = var.region
    event_type            = "google.cloud.pubsub.topic.v1.messagePublished"
    pubsub_topic          = "projects/${var.project_id}/topics/greeny_data_inserted_in_tbl"
    retry_policy          = "RETRY_POLICY_DO_NOT_RETRY"
    service_account_email = var.tf_service_account
  }

How should I create the subscription?

Posting this as a community wiki. As what guillaume blaquiere said, you can opt instead to add an insert date column and perform a request every minute to get the latest row. You can write a script in cloud function and use scheduler to schedule pulling latest data from big query and writing it to another table.<br>