title: What is catalog_connection param in aws glue?
body: <p>I wish to regularly run a etl job at every 4 hours which will union (combine) data from s3 bucket (parquet format) and data from redshift. Find out the unique and then write it again to redshift, replacing old redshift data. For writing dataframes to redshift, <a href="https://docs.aws.amazon.com/glue/latest/dg/aws-glue-api-crawler-pyspark-extensions-dynamic-frame-writer.html#aws-glue-api-crawler-pyspark-extensions-dynamic-frame-writer-from_jdbc_conf" rel="nofollow noreferrer">this</a></p>
  <pre><code>glueContext.write_dynamic_frame.from_jdbc_conf(frame, catalog_connection, connection_options={}, redshift_tmp_dir = &quot;&quot;, transformation_ctx=&quot;&quot;)
  
  Writes a DynamicFrame using the specified JDBC connection information.
  frame – The DynamicFrame to write.
  catalog_connection – A catalog connection to use.
  connection_options – Connection options, such as path and database table (optional).
  redshift_tmp_dir – An Amazon Redshift temporary directory to use (optional).
  transformation_ctx – A transformation context to use (optional).
  </code></pre>
  <p>seems to the way. But what does the <code>catalog_connection</code> mean? Does it refer to glue catalog? If yes, then what in glue catalog?</p>