apache/superset · error · DatabaseUploadFailed

Parsing error: %(error)s

Error message

Parsing error: %(error)s

What it means

Raised as DatabaseUploadFailed with message 'Parsing error: <detail>' when pd.read_parquet fails with a recognized parsing exception (pd.errors.ParserError, pd.errors.EmptyDataError, UnicodeDecodeError, or ValueError) while converting an uploaded Parquet buffer to a DataFrame in ColumnarReader._read_buffer_to_dataframe. The underlying pandas/pyarrow message is embedded so the user sees the actual cause (e.g. 'Invalid parquet file', 'No columns to parse from file').

Source

Thrown at superset/commands/database/uploaders/columnar_reader.py:70

        super().__init__(
            options=dict(options),
        )

    def _read_buffer_to_dataframe(self, buffer: IO[bytes]) -> pd.DataFrame:
        kwargs: dict[str, Any] = {
            "path": buffer,
        }
        if self._options.get("columns_read"):
            kwargs["columns"] = self._options.get("columns_read")
        try:
            return pd.read_parquet(**kwargs)
        except (
            pd.errors.ParserError,
            pd.errors.EmptyDataError,
            UnicodeDecodeError,
            ValueError,
        ) as ex:
            raise DatabaseUploadFailed(
                message=_("Parsing error: %(error)s", error=str(ex))
            ) from ex
        except Exception as ex:
            raise DatabaseUploadFailed(_("Error reading Columnar file")) from ex

    @staticmethod
    def _yield_files(file: FileStorage) -> Generator[IO[bytes], None, None]:
        """
        Yields files from the provided file. If the file is a zip file, it yields each
        file within the zip file. If it's a single file, it yields the file itself.

        :param file: The file to yield files from.
        :return: A generator that yields files.
        """
        file_suffix = Path(file.filename).suffix
        if not file_suffix:
            raise DatabaseUploadFailed(_("Unexpected no file extension found"))
        file_suffix = file_suffix[1:]  # remove the dot

View on GitHub (pinned to f4587218dd)

Solutions

1. Open the file locally with pandas/pyarrow (pd.read_parquet) to reproduce the exact underlying error shown in %(error)s
2. If a column filter was set, verify every name in columns_read matches the file schema exactly (case and whitespace)
3. If uploaded inside a ZIP, confirm every entry is a valid Parquet file; re-zip without OS metadata directories
4. Regenerate or re-upload the file; if it was truncated, check client-side upload limits (e.g. nginx client_max_body_size, Flask MAX_CONTENT_LENGTH)

Example fix

# before: uploading a zip containing 'data.parquet' and '__MACOSX/._data.parquet'
# after: zip only the parquet payload
zip clean.zip data.parquet  # single entry, valid parquet

import pyarrow.parquet as pq

def parquet_is_readable(fh) -> bool:
    try:
        fh.seek(0)
        pq.ParquetFile(fh).metadata  # noqa: force footer parse
        return True
    except Exception:
        return False

from superset.commands.database.exceptions import DatabaseUploadFailed
try:
    reader.file_to_dataframe(file)
except DatabaseUploadFailed as ex:
    # message embeds the pandas/pyarrow cause
    logger.warning("parquet upload failed: %s", ex.message)  # surface to user, keep chained cause

When it happens

Trigger: Uploading a Parquet file that is truncated/corrupt, empty (0 rows or empty file inside a ZIP), or not actually Parquet (e.g. a renamed CSV) via the Superset database 'Upload file to table' flow with the Columnar reader; also when a selected column in 'columns_read' does not exist in the file, causing pyarrow to raise ValueError.

Common situations: File truncated during transfer or HTTP upload size limits; picking arbitrary files from a ZIP where one entry is a __MACOSX metadata file or a non-parquet payload; specifying column names with trailing whitespace or wrong case in the column selection UI; Parquet files written by an incompatible/older pyarrow version.

Related errors

• Error reading Columnar file
• Unexpected no file extension found
• error_msg
• Error reading CSV file
• Parsing error: %(error)s

AI-assisted analysis of apache/superset@f4587218dd (2026-08-14). Data as JSON: /api/errors/4b01bfa7be402ba4. Report an issue: GitHub.