How to Transfer Data from PostgreSQL to MySQL in AWS Glue Without Using Data Catalog for Target?"

While AWS Glue typically uses the Data Catalog for managing metadata and schema information, there are ways to transfer data from PostgreSQL to MySQL without relying on the Data Catalog for the target database. Here's an approach you can consider:

1. Source Connection: Use AWS Glue's built-in support for PostgreSQL as your source. You can create a JDBC connection to your PostgreSQL database directly.

2. ETL Job: Create an ETL job in AWS Glue that reads data from your PostgreSQL source. You can use either PySpark or Scala to write your transformation logic.

3. Transformations: Apply your required transformations to the data within the ETL job.

4. Custom JDBC Connection: Instead of using the Data Catalog for the target, you can create a custom JDBC connection to your MySQL database. AWS Glue allows you to use custom JDBC drivers in your ETL jobs.

5. Direct Write: Use the custom JDBC connection to write the transformed data directly to your MySQL database. You'll need to handle the schema mapping and data insertion in your ETL script.

6. Error Handling: Implement proper error handling and logging in your ETL job to manage any issues that may arise during the data transfer process.

This approach bypasses the need for using the Data Catalog for the target database. However, it's important to note that this method requires more manual configuration and code management. You'll need to ensure that your ETL job correctly handles the schema differences between PostgreSQL and MySQL, and that it properly manages data types and any necessary transformations.

Also, keep in mind that while this method allows you to insert data directly into the target database without relying on the Data Catalog, it may not be as optimized or manageable as using AWS Glue's native features. You'll need to handle aspects like performance tuning, error recovery, and schema evolution manually in your ETL code.

Remember to consider security implications and ensure that your custom JDBC connection is properly secured and that it complies with your organization's data handling policies.

Sources
Using custom connectors and connections with AWS Glue Studio - AWS Glue
AWS Glue: How it works - AWS Glue