title: Is it required to run AWS Glue crawler to detect new data before executing an ETL job?
body: <p>AWS Glue docs clearly states that Crawlers scrapes metadata information from the source (JDBS or s3) and populates Data Catalog (creates/updates DB and corresponding tables).</p>
  
  <p>However, it's not clear whether we need to run a crawler regularly to detect new data in a source (ie, new objects on s3, new rows in db table) if we know that there no scheme/partitioning changes.</p>
  
  <p>So, is it required to run a crawler prior to running an ETL job to be able to pick up a new data?</p>