Custom Rule in Data Quality Rules in DataBrew Selection for Financial Dataset

I apologize, but I don't have specific information about implementing a custom rule exactly as you've described using regular expressions in AWS Glue Data Quality. However, I can provide some general guidance on creating custom data quality rules in AWS Glue that may be helpful for your situation.

Instead of using regular expressions, you might want to consider using the Data Quality Definition Language (DQDL) in AWS Glue to create your custom rule. DQDL allows for more complex rule creation, including composite rules and mathematical operations.

For your specific rule (Portfolio Return * Net Assets > 10% of Debt), you would need to create a composite rule that involves multiple columns and a calculation. While I don't have an exact syntax for this rule, you could potentially structure it using DQDL's composite rule capabilities and mathematical operations.

Here's a general approach you could try:

1. Use the DQDL rule builder in AWS Glue Studio to create your custom rule.
2. Utilize the composite rule feature to combine multiple conditions or calculations.
3. Use mathematical operations to perform the necessary calculations (multiplication and percentage comparison).
4. Apply a WHERE clause if you need to filter the data before applying the rule.

If you're still encountering errors after trying this approach, you may need to check the following:

1. Ensure that your column names are correct and match exactly with your dataset.
2. Verify that the data types of your columns are appropriate for the calculations you're trying to perform.
3. Check if there are any null or invalid values in your dataset that might be causing issues with the rule execution.

If problems persist, you might want to start with simpler rules and gradually build up to your complex rule, testing at each step to identify where the issue might be occurring.

Remember, AWS Glue Data Quality is designed to help you measure and monitor the quality of your data, so don't hesitate to iterate on your rules until you achieve the desired results.
Sources
Data Quality rule builder - AWS Glue
Announcing Data Quality Definition Language (DQDL) enhancements for AWS Glue Data Quality - AWS