risingwavelabs/risingwave · error · ConnectorError

Unknown MySQL data type

Error message

Unknown MySQL data type

What it means

The mapper hit a MySQL ColumnType::Unknown — a type byte it cannot recognize at all — so it cannot produce a RisingWave DataType and returns this error. Unlike the spatial types, this signals the connector didn't even identify the type, usually meaning a very new or exotic MySQL type.

Solutions

1. Check the MySQL server/version; upgrade the mysql parser dependency (rust-cdc-connect crate) so new type codes are recognized.
2. Alter the offending column to a standard supported type.
3. Inspect the upstream schema and remove/vendor-specific columns from the CDC table.
4. Report the unrecognized type to RisingWave with server version and schema.

Example fix

// before (upstream)
CREATE TABLE t (id INT PRIMARY KEY, weird_col VENDOR_TYPE);
// after
ALTER TABLE t MODIFY weird_col VARCHAR(255);

// Verify all upstream column types are known standard MySQL types before CDC:
let known = ["tinyint","smallint","mediumint","int","bigint","decimal","float","double","bit","date","datetime","timestamp","time","year","char","varchar","binary","varbinary","blob","text","enum","set","json"];
for col in mysql_columns {
    if !known.iter().any(|t| col.data_type.eq_ignore_ascii_case(t)) && !col.data_type.eq_ignore_ascii_case("geometry") {
        eprintln!("non-standard column type: {} {}", col.name, col.data_type);
    }
}

match connect_mysql_cdc(schema).await {
    Err(e) if e.to_string().contains("Unknown MySQL data type") => {
        eprintln!("Unrecognized column type; check MySQL version/parser support: {e}");
    }
    other => other?,
}

When it happens

Trigger: connect or parse_schema_change encounters a column whose mysql-parser ColumnType resolves to Unknown (unrecognized type code in the binary-log/schema payload).

Common situations: Very new MySQL/MariaDB versions introducing new types, proxies emitting unusual metadata, or vendor-specific column types (e.g. some TiDB/Aurora specifics) appearing in CDC schema.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• MySQL table doesn't define the primary key
• unsupported data type
• BIT( ) type not supported
• Column type mismatch
• snapshot primary key ` ` cannot be NULL

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/341a67c0fa62eec1. Report an issue: GitHub.

Appendix: source

Thrown at src/connector/src/source/cdc/external/mysql.rs:447

            return Err(anyhow!("LINE string type not supported").into());
        }
        ColumnType::Polygon(_) => {
            return Err(anyhow!("POLYGON type not supported").into());
        }
        ColumnType::MultiPoint(_) => {
            return Err(anyhow!("MULTI POINT type not supported").into());
        }
        ColumnType::MultiLineString(_) => {
            return Err(anyhow!("MULTI LINE STRING type not supported").into());
        }
        ColumnType::MultiPolygon(_) => {
            return Err(anyhow!("MULTI POLYGON type not supported").into());
        }
        ColumnType::GeometryCollection(_) => {
            return Err(anyhow!("GEOMETRY COLLECTION type not supported").into());
        }
        ColumnType::Unknown(_) => {
            return Err(anyhow!("Unknown MySQL data type").into());
        }
    };

    Ok(dtype)
}

pub struct MySqlExternalTableReader {
    rw_schema: Schema,
    pk_indices: Vec<usize>,
    field_names: String,
    pool: mysql_async::Pool,
    upstream_mysql_pk_infos: Vec<(String, ColumnType)>, // (column_name, column_type)
    mysql_version: (u8, u8),
    is_mariadb: bool,
}

impl ExternalTableReader for MySqlExternalTableReader {
    async fn current_cdc_offset(&self) -> ConnectorResult<CdcOffset> {

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