It seems MaterializeMySQL doesn't support Decimal data type when doing replication.
{
        vtUInt8,
        vtUInt16,
        vtUInt32,
        vtUInt64,
        vtInt8,
        vtInt16,
        vtInt32,
        vtInt64,
        vtFloat32,
        vtFloat64,
        vtString,
        vtDate,
        vtDateTime,
        vtUUID,
        vtDateTime64,
        vtDecimal32,
        vtDecimal64,
        vtDecimal128
    };
    Block sample_block;
    std::vector<std::pair<ValueType, bool >> types;
    void init(const Block & sample_block_);
};
}