pathwaycom/pathway · error · ValueError

The suggested partition column {column} doesn't belong to th

Error message

The suggested partition column {column} doesn't belong to the table {table}

What it means

Error "The suggested partition column {column} doesn't belong to the table {table}" thrown in pathwaycom/pathway.

Source

Thrown at python/pathway/io/deltalake/__init__.py:656

    A string that can't be parsed as a decimal of the column's shape (non-digit
    characters, more fractional digits than the column's scale, or more total digits
    than its precision) fails the write with an error message naming the offending
    value, the column's precision and scale, and the specific constraint it violated.
    Tables that don't contain a ``decimal`` column are unaffected: writing a Pathway Live Data Framework
    ``str`` column into a fresh table or into an existing Delta ``string`` column
    behaves exactly as before.
    """
    _check_entitlements("deltalake")
    prepared_connection_settings = _prepare_s3_connection_settings(
        s3_connection_settings
    )

    prepared_partition_columns = []
    if partition_columns is not None:
        for column in partition_columns:
            if column._table != table:
                raise ValueError(
                    f"The suggested partition column {column} doesn't belong to the table {table}"
                )
            prepared_partition_columns.append(column._name)

    uri = fspath(uri)
    data_storage = api.DataStorage(
        storage_type="deltalake",
        path=uri,
        aws_s3_settings=_engine_s3_connection_settings(
            uri, prepared_connection_settings
        ),
        min_commit_frequency=min_commit_frequency,
        partition_columns=prepared_partition_columns,
        snapshot_maintenance_on_output=output_table_type == SNAPSHOT_OUTPUT_TABLE_TYPE,
        delta_optimizer_rule=(table_optimizer.engine_rule if table_optimizer else None),
    )
    data_format = api.DataFormat(
        format_type="identity",

View on GitHub (pinned to fa2f74a464)

Solutions

1. Pass partition columns that belong to the table being written.

Example fix

pw.io.deltalake.write(t, uri, partition_columns=[t.date])

When it happens

Trigger: Thrown at python/pathway/io/deltalake/__init__.py:656 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pathwaycom/pathway@fa2f74a464 (2026-08-15). Data as JSON: /api/errors/9ec7d7443b88ea61. Report an issue: GitHub.