Troubleshooting Guide


Materialized Views (MV)

Create

datacoral organize matview-create --dpl-file events.dpl

Error: Materialized view can't be created. At least one of the dependencies' intervalInMinutes should be less than or equal to the materialized view's intervalInMinutes.

As part of MV create, we extract dependencies of the query and compute interval-in-minutes of the dependenices. The above error occurs in one of the following cases:

  • All the dependencies interval-in-minutes of the dependencies are greater than MV's interval-in-minutes.

    • Create the MV with greater or equal dependencies' interval-in-minutes.
  • None of the dependencies of the query are owned by datacoral

JSON parsing error

This error is applicable for Redshift warehouse only. Redshift supports JSON datatype extraction through specific functions.

Error:

error: JSON parsing error``code: 8001``context: invalid json object 123``query: 18976712

These are the few circumstances when a query will result in JSON parsing error

  1. NULL values: Functions such as JSON_EXTRACT_PATH_TEXT function will throw an error in case the NULL values are not handled
    • Add null_if_invalid argument in the JSON function
  2. Column truncate: The maximum byte size supported by Redshift is 65535. A column value exceeding this limit will be truncated at the Redshift warehouse, hence will not remain in JSON format
    • Add a boolean condition at the MV to check for size can be used to prevent the error
  3. Incorrect source datatype: At the source there could be a non-JSON format string input
    • Add a condition in the MV to check if the input string is in a JSON format to begin with