公司举办了关于新技术的培训，提到了“大数据”这个对我而言火了有几年的概念。所以，有必要当好“小学生”了，不懂的字该怎么办，查字典。不懂的概念怎么办，学习呗！
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大数据（big data），指无法在一定时间范围内用常规软件工具进行捕捉、管理和处理的数据集合，是需要新处理模式才能具有更强的决策力、洞察发现力和流程优化能力的海量、高增长率和多样化的信息资产。
在维克托·迈尔-舍恩伯格及肯尼斯·库克耶编写的《大数据时代》中大数据指不用随机分析法（抽样调查）这样捷径，而采用所有数据进行分析处理。大数据的5V特点（IBM提出）：Volume（大量）、Velocity（高速）、Variety（多样）、Value（低价值密度）、Veracity（真实性）。
对于“大数据”（Big data）研究机构Gartner给出了这样的定义。“大数据”是需要新处理模式才能具有更强的决策力、洞察发现力和流程优化能力来适应海量、高增长率和多样化的信息资产。
麦肯锡全球研究所给出的定义是：一种规模大到在获取、存储、管理、分析方面大大超出了传统数据库软件工具能力范围的数据集合，具有海量的数据规模、快速的数据流转、多样的数据类型和价值密度低四大特征。
大数据技术的战略意义不在于掌握庞大的数据信息，而在于对这些含有意义的数据进行专业化处理。换而言之，如果把大数据比作一种产业，那么这种产业实现盈利的关键，在于提高对数据的“加工能力”，通过“加工”实现数据的“增值”。
从技术上看，大数据与云计算的关系就像一枚硬币的正反面一样密不可分。大数据必然无法用单台的计算机进行处理，必须采用分布式架构。它的特色在于对海量数据进行分布式数据挖掘。但它必须依托云计算的分布式处理、分布式数据库和云存储、虚拟化技术。
随着云时代的来临，大数据（Big data）也吸引了越来越多的关注。分析师团队认为，大数据（Big data）通常用来形容一个公司创造的大量非结构化数据和半结构化数据，这些数据在下载到关系型数据库用于分析时会花费过多时间和金钱。大数据分析常和云计算联系到一起，因为实时的大型数据集分析需要像MapReduce一样的框架来向数十、数百或甚至数千的电脑分配工作。
大数据需要特殊的技术，以有效地处理大量的容忍经过时间内的数据。适用于大数据的技术，包括大规模并行处理（MPP）数据库、数据挖掘、分布式文件系统、分布式数据库、云计算平台、互联网和可扩展的存储系统。
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Big data is data sets that are so big and complex that traditional data-processing application software are inadequate to deal with them. Big data challenges include capturing data, data storage, data analysis, search, sharing, transfer, visualization, querying, updating, information privacy and data source. There are a number of concepts associated with big data: originally there were 3 concepts volume, variety, velocity. Other concepts later attributed with big data are veracity (i.e., how much noise is in the data) and value.
Lately, the term "big data" tends to refer to the use of predictive analytics, user behavior analytics, or certain other advanced data analytics methods that extract value from data, and seldom to a particular size of data set. "There is little doubt that the quantities of data now available are indeed large, but that’s not the ost relevant characteristic of this new data ecosystem." Analysis of data sets can find new correlations to "spot business trends, prevent diseases, combat crime and so on." Scientists, business executives, practitioners of medicine, advertising and governments alike regularly meet difficulties with large data-sets in areas including Internet search, fintech, urban informatics, and business informatics. Scientists encounter limitations in e-Science work, including meteorology, genomics, connectomics, complex physics simulations, biology and environmental research.
Data sets grow rapidly - in part because they are increasingly gathered by cheap and numerous information-sensing Internet of things devices such as mobile devices, aerial (remote sensing), software logs, cameras, microphones, radio-frequency identification (RFID) readers and wireless sensor networks. The world's technological per-capita capacity to store information has roughly doubled every 40 months since the 1980s;as of 2012, every day 2.5 exabytes (2.5×10^18) of data are generated. Based on an IDC report prediction, the global data volume will grow exponentially from 4.4 zettabytes to 44 zettabytes between 2013 and 2020.By 2025, IDC predicts there will be 163 zettabytes of data. One question for large enterprises is determining who should own big-data initiatives that affect the entire organization.
Relational database management systems and desktop statistics and software packages to visualize data often have difficulty handling big data. The work may require "massively parallel software running on tens, hundreds, or even thousands of servers". What counts as "big data" varies depending on the capabilities of the users and their tools, and expanding capabilities make big data a moving target. "For some organizations, facing hundreds of gigabytes of data for the first time may trigger a need to reconsider data management options. For others, it may take tens or hundreds of terabytes before data size becomes a significant consideration."