• The error is caused by a difference in the format of the transaction isolation level command between PostgreSQL and Risingwave.
• Risingwave only supports the format show transaction_isolation_level;, while PostgreSQL allows both show transaction isolation level; and show transaction_isolation_level;.
• To fix this error in the current version, you can manually adjust the transaction isolation level command in the Superset configuration to match Risingwave's format.

Example:

# Update the transaction isolation level command in the Superset configuration
config['SQLALCHEMY_EXTRAS'] = {
    'engine_params': {
        'isolation_level': 'READ COMMITTED'
    }
}

• Alternatively, you can wait for the fix to be released in Risingwave v1.5.1 next week.