title: Setting up a BigQuery to Google Cloud Storage pipeline with overwriting
body: <p>I am trying to setup a really simple pipeline in Data Fusion which takes a table from BigQuery, then stores that data into Google Cloud Storage. With the pipeline setup below it's fairly easy. We first read the bigquery table and schema, then sink the data into a Google Cloud Storage bucket. This works, but the problem is that a new map and a new file gets created for each new transfer that I run. What I would like to do is to overwrite a single file in the same filepath with each new transfer that I do.</p>
  
  <p><a href="https://i.stack.imgur.com/NsuMj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NsuMj.png" alt="enter image description here"></a></p>
  
  <p>What I ran into that in this setup, a new map and a new file gets within Google Cloud Storage created using a timestamp prefix. Looking at the sink configuration below, indeed, by default you see a timestamp.</p>
  
  <p><a href="https://i.stack.imgur.com/GbAJ0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GbAJ0.png" alt="enter image description here"></a></p>
  
  <p>Alright, that would mean if I would remove the prefix a new map shouldn't be created. The hover-over confirms this: "If not specified, nothing will be appended to the path". </p>
  
  <p><a href="https://i.stack.imgur.com/CjbKN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CjbKN.png" alt="enter image description here"></a></p>
  
  <p>However, when I clear this value and then save it, the full time format automatically pops up again. I can't use a static value because this results in errors. For example I just tried creating a map with the number "12" in Google Cloud Storage and then setting the prefix to that, but as you would guess this doesn't work. Is anyone else running into this problem? How do I get rid of the path suffix so I don't get a new map for each timestamp within Google Cloud Storage?</p>