Always handle error conditions explicitly rather than silently ignoring them or using generic error responses. Use specific error codes that reflect business logic rather than low-level system errors, and throw exceptions for unexpected states instead of using assertions or returning generic failure indicators. Key principles: 1. **Throw specific exceptions** for unexpected conditions rather than using assertions that can cause segfaults 2. **Use business-logic error codes** instead of generic system-level codes to provide better context 3. **Explicitly check expected error conditions** and throw exceptions for unexpected ones 4. **Avoid silent failures** - parse and validate inputs completely, throwing unsupported exceptions for unhandled cases Example of good explicit error handling: ```cpp // Instead of silent failure or generic error if (code != Coordination::Error::ZOK) return false; // BAD: silently ignores all error types // Be explicit about expected vs unexpected errors if (code == Coordination::Error::ZNONODE || code == Coordination::Error::ZNOAUTH) return false; // Expected errors else if (Coordination::isHardwareError(code)) throw Exception(ErrorCodes::ZOOKEEPER_EXCEPTION, "Hardware error: {}", code); // Unexpected errors // Use specific error codes that reflect business context throw Exception(ErrorCodes::UDF_EXECUTION_FAILED, "UDF execution failed: {}", details); // Instead of generic: ErrorCodes::CANNOT_WRITE_TO_FILE_DESCRIPTOR // Replace assertions with proper exceptions chassert(tuple_function->arguments->children.size() == partition_columns.size()); // BAD if (tuple_function->arguments->children.size() != partition_columns.size()) throw Exception(ErrorCodes::LOGICAL_ERROR, "Partition argument count mismatch"); // GOOD ``` This approach improves debugging, provides better user experience, and prevents silent corruption of program state.