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apache / iotdb-website / 42e1606f91da01e72dd32f30dda97c5c7763fdda / . / assets / js / 374.71d42042.js
blob: fe62a87205a310cefcac9ea599c09de803677ce9 [file] [log] [blame]
(window.webpackJsonp=window.webpackJsonp||[]).push([[374],{938:function(t,e,v){"use strict";v.r(e);var a=v(68),_=Object(a.a)({},(function(){var t=this,e=t.$createElement,v=t._self._c||e;return v("ContentSlotsDistributor",{attrs:{"slot-key":t.$parent.slotKey}},[v("h1",{attrs:{id:"数据模型与技术"}},[v("a",{staticClass:"header-anchor",attrs:{href:"#数据模型与技术"}},[t._v("#")]),t._v(" 数据模型与技术")]),t._v(" "),v("p",[t._v("我们为您提供一份简化的"),v("a",{attrs:{href:"https://github.com/thulab/iotdb/files/4438687/OtherMaterial-Sample.Data.txt",target:"_blank",rel:"noopener noreferrer"}},[t._v("样例数据"),v("OutboundLink")],1),t._v("。")]),t._v(" "),v("p",[t._v("下载文件: "),v("a",{attrs:{href:"https://github.com/thulab/iotdb/files/4438687/OtherMaterial-Sample.Data.txt",target:"_blank",rel:"noopener noreferrer"}},[t._v("IoTDB-SampleData.txt"),v("OutboundLink")],1),t._v(".")]),t._v(" "),v("p",[t._v("根据本文描述的"),v("a",{attrs:{href:"https://github.com/thulab/iotdb/files/4438687/OtherMaterial-Sample.Data.txt",target:"_blank",rel:"noopener noreferrer"}},[t._v("数据"),v("OutboundLink")],1),t._v("属性层级，按照属性涵盖范围以及它们之间的从属关系，我们可将其表示为如下图2.1的属性层级组织结构，其层级关系为：集团层-电场层-设备层-传感器层。其中ROOT为根节点，传感器层的每一个节点称为叶子节点。在使用IoTDB的过程中，您可以直接将由ROOT节点到每一个叶子节点路径上的属性用“.”连接，将其作为一个IoTDB的时间序列的名称。图2.1中最左侧的路径可以生成一个名为"),v("code",[t._v("ROOT.ln.wf01.wt01.status")]),t._v("的时间序列。")]),t._v(" "),v("center",[v("img",{staticStyle:{width:"100%","max-width":"800px","max-height":"600px","margin-left":"auto","margin-right":"auto",display:"block"},attrs:{src:"https://user-images.githubusercontent.com/13203019/51577327-7aa50780-1ef4-11e9-9d75-cadabb62444e.jpg"}})]),t._v(" "),v("p",[v("strong",[t._v("图2.1 属性层级组织结构")])]),t._v(" "),v("p",[t._v("得到时间序列的名称之后，我们需要根据数据的实际场景和规模设置存储组。由于在本文所述场景中，每次到达的数据通常以集团为单位（即数据可能为跨电场、跨设备的），为了写入数据时避免频繁切换IO降低系统速度，且满足用户以集团为单位进行物理隔离数据的要求，我们将存储组设置在集团层。")]),t._v(" "),v("p",[t._v("根据模型结构，IoTDB中涉及如下基本概念：")]),t._v(" "),v("ul",[v("li",[t._v("设备")])]),t._v(" "),v("p",[t._v("设备指的是在实际场景中拥有传感器的装置。在IoTDB当中，所有的传感器都应有其对应的归属的设备。")]),t._v(" "),v("ul",[v("li",[t._v("传感器")])]),t._v(" "),v("p",[t._v("传感器是指在实际场景中的一种检测装置，它能感受到被测量的信息，并能将感受到的信息按一定规律变换成为电信号或其他所需形式的信息输出并发送给IoTDB。在IoTDB当中，存储的所有的数据及路径，都是以传感器为单位进行组织。")]),t._v(" "),v("ul",[v("li",[t._v("存储组")])]),t._v(" "),v("p",[t._v("用户可以将任意前缀路径设置成存储组。如有4条时间序列"),v("code",[t._v("root.vehicle.d1.s1")]),t._v(", "),v("code",[t._v("root.vehicle.d1.s2")]),t._v(", "),v("code",[t._v("root.vehicle.d2.s1")]),t._v(", "),v("code",[t._v("root.vehicle.d2.s2")]),t._v("，路径"),v("code",[t._v("root.vehicle")]),t._v("下的两个设备d1,d2可能属于同一个业主，或者同一个厂商，因此关系紧密。这时候就可以将前缀路径"),v("code",[t._v("root.vehicle")]),t._v("指定为一个存储组，这将使得IoTDB将其下的所有设备的数据存储在同一个文件夹下。未来"),v("code",[t._v("root.vehicle")]),t._v("下增加了新的设备，也将属于该存储组。")]),t._v(" "),v("blockquote",[v("p",[t._v("注意：不允许将一个完整路径(如上例的"),v("code",[t._v("root.vehicle.d1.s1")]),t._v(")设置成存储组。")])]),t._v(" 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"),v("div",{staticClass:"line-numbers-wrapper"},[v("span",{staticClass:"line-number"},[t._v("1")]),v("br"),v("span",{staticClass:"line-number"},[t._v("2")]),v("br")])]),v("p",[t._v("其中STAR为“*”，DOT为“.”。")]),t._v(" "),v("p",[t._v("我们称一个路径中在两个“.”中间的部分叫做一个层级，则"),v("code",[t._v("root.a.b.c")]),t._v("为一个层级为4的路径。")]),t._v(" "),v("p",[t._v("值得说明的是，在路径中，root为一个保留字符，它只允许出现在下文提到的时间序列的开头，若其他层级出现root，则无法解析，提示报错。")]),t._v(" "),v("ul",[v("li",[t._v("时间序列")])]),t._v(" "),v("p",[t._v("时间序列是IoTDB中的核心概念。时间序列可以被看作产生时序数据的传感器的所在完整路径，在IoTDB中所有的时间序列必须以root开始、以传感器作为结尾。一个时间序列也可称为一个全路径。")]),t._v(" "),v("p",[t._v("例如，vehicle种类的device1有名为sensor1的传感器，则它的时间序列可以表示为："),v("code",[t._v("root.vehicle.device1.sensor1")]),t._v("。")]),t._v(" "),v("blockquote",[v("p",[t._v("注意：当前IoTDB支持的时间序列必须大于等于四层（之后会更改为两层）。")])]),t._v(" "),v("ul",[v("li",[t._v("前缀路径")])]),t._v(" "),v("p",[t._v("前缀路径是指一个时间序列的前缀所在的路径，一个前缀路径包含以该路径为前缀的所有时间序列。例如当前我们有"),v("code",[t._v("root.vehicle.device1.sensor1")]),t._v(", 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"),v("ul",[v("li",[t._v("时间戳")])]),t._v(" "),v("p",[t._v("时间戳是一个数据到来的时间点，其中包括绝对时间戳和相对时间戳。")]),t._v(" "),v("ul",[v("li",[t._v("绝对时间戳")])]),t._v(" "),v("p",[t._v("IOTDB中绝对时间戳分为二种，一种为LONG类型，一种为DATETIME类型（包含DATETIME-INPUT, DATETIME-DISPLAY两个小类）。")]),t._v(" "),v("p",[t._v("在用户在输入时间戳时，可以使用LONG类型的时间戳或DATETIME-INPUT类型的时间戳，其中DATETIME-INPUT类型的时间戳支持格式如表所示：")]),t._v(" "),v("center",[t._v("**DATETIME-INPUT类型支持格式**\n"),v("table",[v("thead",[v("tr",[v("th",{staticStyle:{"text-align":"left"}},[t._v("format")])])]),t._v(" "),v("tbody",[v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy-MM-dd HH:mm:ss")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy/MM/dd HH:mm:ss")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy.MM.dd HH:mm:ss")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy-MM-dd'T'HH:mm:ss")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy/MM/dd'T'HH:mm:ss")])]),t._v(" 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"),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy/MM/dd'T'HH:mm:ss.SSS")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy-MM-dd'T'HH:mm:ss.SSS")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy.MM.dd'T'HH:mm:ss.SSS")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy-MM-dd HH:mm:ss.SSSZZ")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy/MM/dd HH:mm:ss.SSSZZ")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy.MM.dd HH:mm:ss.SSSZZ")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy-MM-dd'T'HH:mm:ss.SSSZZ")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy/MM/dd'T'HH:mm:ss.SSSZZ")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("yyyy.MM.dd'T'HH:mm:ss.SSSZZ")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"left"}},[t._v("ISO8601 standard time 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"),v("td",{staticStyle:{"text-align":"center"}},[t._v("number")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("20")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}},[t._v("Y")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("year of era (>=0)")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("year")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("1996")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}}),t._v(" "),v("td",{staticStyle:{"text-align":"center"}}),t._v(" "),v("td",{staticStyle:{"text-align":"center"}}),t._v(" "),v("td",{staticStyle:{"text-align":"center"}})]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}},[t._v("x")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("weekyear")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("year")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("1996")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}},[t._v("w")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("week of weekyear")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("number")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("27")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}},[t._v("e")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("day of week")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("number")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("2")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}},[t._v("E")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("day of week")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("text")]),t._v(" "),v("td",{staticStyle:{"text-align":"center"}},[t._v("Tuesday; Tue")])]),t._v(" "),v("tr",[v("td",{staticStyle:{"text-align":"center"}}),t._v(" 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