Big data is a term used to refer to data sets that are too large or complex for traditional data-processing application software to adequately deal with.Data with many cases(rows) offer greater statistical power,while data with higher complexity (more attributes or columns) may lead to a higher false discovery rate.Big data challenges include capturing data,data storage,data analysis,search,sharing,transfer,visualization,querying,updating,information privacy and data source.Big data was originally associated with three key concepts:volume,variety and velocity.Other concepts later attributed with big data are veracity(i.e.,how much noise is in the data) and value.
来源是维基百科对大数据的定义（https://en.wikipedia.org/wiki/Big_data）