| <!doctype html> |
| <html lang="zh-CN" data-theme="light"> |
| <head> |
| <meta charset="utf-8" /> |
| <meta name="viewport" content="width=device-width,initial-scale=1" /> |
| <meta name="generator" content="VuePress 2.0.0-rc.9" /> |
| <meta name="theme" content="VuePress Theme Hope 2.0.0-rc.34" /> |
| <style> |
| html { |
| background: var(--bg-color, #fff); |
| } |
| |
| html[data-theme="dark"] { |
| background: var(--bg-color, #1d1e1f); |
| } |
| |
| body { |
| background: var(--bg-color); |
| } |
| </style> |
| <script> |
| const userMode = localStorage.getItem("vuepress-theme-hope-scheme"); |
| const systemDarkMode = |
| window.matchMedia && |
| window.matchMedia("(prefers-color-scheme: dark)").matches; |
| |
| if (userMode === "dark" || (userMode !== "light" && systemDarkMode)) { |
| document.documentElement.setAttribute("data-theme", "dark"); |
| } |
| </script> |
| <link rel="alternate" hreflang="en-us" href="https://iotdb.apache.org/UserGuide/V1.0.x/Query-Data/Continuous-Query.html"><meta property="og:url" content="https://iotdb.apache.org/zh/UserGuide/V1.0.x/Query-Data/Continuous-Query.html"><meta property="og:site_name" content="IoTDB Website"><meta property="og:title" content="连续查询（Continuous Query, CQ）"><meta property="og:description" content="连续查询（Continuous Query, CQ） 简介 连续查询(Continuous queries, aka CQ) 是对实时数据周期性地自动执行的查询，并将查询结果写入指定的时间序列中。 语法 注意： 如果where子句中出现任何时间过滤条件，IoTDB将会抛出异常，因为IoTDB会自动为每次查询执行指定时间范围。 GROUP BY TIME..."><meta property="og:type" content="article"><meta property="og:image" content="https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic1.png?raw=true"><meta property="og:locale" content="zh-CN"><meta property="og:locale:alternate" content="en-US"><meta property="og:updated_time" content="2023-07-10T03:11:17.000Z"><meta property="article:modified_time" content="2023-07-10T03:11:17.000Z"><script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"连续查询（Continuous Query, CQ）","image":["https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic1.png?raw=true","https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic2.png?raw=true","https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic3.png?raw=true","https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic4.png?raw=true"],"dateModified":"2023-07-10T03:11:17.000Z","author":[]}</script><link rel="icon" href="/favicon.ico"><meta name="Description" content="Apache IoTDB: Time Series Database for IoT"><meta name="Keywords" content="TSDB, time series, time series database, IoTDB, IoT database, IoT data management,时序数据库, 时间序列管理, IoTDB, 物联网数据库, 实时数据库, 物联网数据管理, 物联网数据"><meta name="baidu-site-verification" content="wfKETzB3OT"><meta name="google-site-verification" content="mZWAoRY0yj_HAr-s47zHCGHzx5Ju-RVm5wDbPnwQYFo"><script type="text/javascript"> |
| var _paq = window._paq = window._paq || []; |
| /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ |
| _paq.push(["setDoNotTrack", true]); |
| _paq.push(["disableCookies"]); |
| _paq.push(['trackPageView']); |
| _paq.push(['enableLinkTracking']); |
| (function() { |
| var u="https://analytics.apache.org/"; |
| _paq.push(['setTrackerUrl', u+'matomo.php']); |
| _paq.push(['setSiteId', '56']); |
| var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; |
| g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); |
| })(); |
| </script><title>连续查询（Continuous Query, CQ） | IoTDB Website</title><meta name="description" content="连续查询（Continuous Query, CQ） 简介 连续查询(Continuous queries, aka CQ) 是对实时数据周期性地自动执行的查询，并将查询结果写入指定的时间序列中。 语法 注意： 如果where子句中出现任何时间过滤条件，IoTDB将会抛出异常，因为IoTDB会自动为每次查询执行指定时间范围。 GROUP BY TIME..."> |
| <link rel="preload" href="/assets/style-DnEHAOmf.css" as="style"><link rel="stylesheet" href="/assets/style-DnEHAOmf.css"> |
| <link rel="modulepreload" href="/assets/app-DrPcRZG6.js"><link rel="modulepreload" href="/assets/Continuous-Query.html-Bjwcioe6.js"> |
| |
| </head> |
| <body> |
| <div id="app"><!--[--><!--[--><!--[--><span tabindex="-1"></span><a href="#main-content" class="vp-skip-link sr-only">跳至主要內容</a><!--]--><!--[--><div class="theme-container has-toc"><!--[--><header id="navbar" class="vp-navbar hide-icon"><div class="vp-navbar-start"><button type="button" class="vp-toggle-sidebar-button" title="Toggle Sidebar"><span class="icon"></span></button><!--[--><!----><!--]--><!--[--><a class="route-link vp-brand" href="/zh/"><img class="vp-nav-logo" src="/logo.png" alt><!----><span class="vp-site-name hide-in-pad">IoTDB Website</span></a><!--]--><!--[--><!----><!--]--></div><div class="vp-navbar-center"><!--[--><!----><!--]--><!--[--><!--]--><!--[--><!----><!--]--></div><div class="vp-navbar-end"><!--[--><!----><!--]--><!--[--><!--[--><div id="docsearch-container" style="display:none;"></div><div><button type="button" class="DocSearch DocSearch-Button" aria-label="搜索文档"><span class="DocSearch-Button-Container"><svg width="20" height="20" class="DocSearch-Search-Icon" viewBox="0 0 20 20"><path d="M14.386 14.386l4.0877 4.0877-4.0877-4.0877c-2.9418 2.9419-7.7115 2.9419-10.6533 0-2.9419-2.9418-2.9419-7.7115 0-10.6533 2.9418-2.9419 7.7115-2.9419 10.6533 0 2.9419 2.9418 2.9419 7.7115 0 10.6533z" stroke="currentColor" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">搜索文档</span></span><span class="DocSearch-Button-Keys"><kbd class="DocSearch-Button-Key"><svg width="15" height="15" class="DocSearch-Control-Key-Icon"><path d="M4.505 4.496h2M5.505 5.496v5M8.216 4.496l.055 5.993M10 7.5c.333.333.5.667.5 1v2M12.326 4.5v5.996M8.384 4.496c1.674 0 2.116 0 2.116 1.5s-.442 1.5-2.116 1.5M3.205 9.303c-.09.448-.277 1.21-1.241 1.203C1 10.5.5 9.513.5 8V7c0-1.57.5-2.5 1.464-2.494.964.006 1.134.598 1.24 1.342M12.553 10.5h1.953" stroke-width="1.2" stroke="currentColor" fill="none" stroke-linecap="square"></path></svg></kbd><kbd class="DocSearch-Button-Key">K</kbd></span></button></div><!--]--><nav class="vp-nav-links"><div class="vp-nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="文档"><span class="title"><!---->文档</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/latest/QuickStart/QuickStart.html" aria-label="v1.3.x"><!---->v1.3.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V1.2.x/QuickStart/QuickStart.html" aria-label="v1.2.x"><!---->v1.2.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V1.1.x/QuickStart/QuickStart.html" aria-label="v1.1.x"><!---->v1.1.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V1.0.x/QuickStart/QuickStart.html" aria-label="v1.0.x"><!---->v1.0.x<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/UserGuide/V0.13.x/QuickStart/QuickStart.html" aria-label="v0.13.x"><!---->v0.13.x<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=177051872" rel="noopener noreferrer" target="_blank" aria-label="系统设计" class="nav-link"><!---->系统设计<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="vp-nav-item hide-in-mobile"><a class="route-link nav-link" href="/zh/Download/" aria-label="下载"><!---->下载<!----></a></div><div class="vp-nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="社区"><span class="title"><!---->社区</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/About.html" aria-label="关于社区"><!---->关于社区<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Development-Guide.html" aria-label="贡献指南"><!---->贡献指南<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Powered-By.html" aria-label="社区伙伴"><!---->社区伙伴<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Feedback.html" aria-label="交流与反馈"><!---->交流与反馈<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Materials.html" aria-label="活动与报告"><!---->活动与报告<!----></a></li><li class="dropdown-item"><a class="route-link nav-link" href="/zh/Community/Community-Project-Committers.html" aria-label="Commiters"><!---->Commiters<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="ASF"><span class="title"><!---->ASF</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="https://www.apache.org/" rel="noopener noreferrer" target="_blank" aria-label="基金会" class="nav-link"><!---->基金会<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/licenses/" rel="noopener noreferrer" target="_blank" aria-label="许可证" class="nav-link"><!---->许可证<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/security/" rel="noopener noreferrer" target="_blank" aria-label="安全" class="nav-link"><!---->安全<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/sponsorship.html" rel="noopener noreferrer" target="_blank" aria-label="赞助" class="nav-link"><!---->赞助<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/thanks.html" rel="noopener noreferrer" target="_blank" aria-label="致谢" class="nav-link"><!---->致谢<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/events/current-event" rel="noopener noreferrer" target="_blank" aria-label="活动" class="nav-link"><!---->活动<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://privacy.apache.org/policies/privacy-policy-public.html" rel="noopener noreferrer" target="_blank" aria-label="隐私" class="nav-link"><!---->隐私<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li></ul></button></div></div></nav><div class="vp-nav-item"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="选择语言"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon i18n-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="i18n icon" style="width:1rem;height:1rem;vertical-align:middle;"><path d="M379.392 460.8 494.08 575.488l-42.496 102.4L307.2 532.48 138.24 701.44l-71.68-72.704L234.496 460.8l-45.056-45.056c-27.136-27.136-51.2-66.56-66.56-108.544h112.64c7.68 14.336 16.896 27.136 26.112 35.84l45.568 46.08 45.056-45.056C382.976 312.32 409.6 247.808 409.6 204.8H0V102.4h256V0h102.4v102.4h256v102.4H512c0 70.144-37.888 161.28-87.04 210.944L378.88 460.8zM576 870.4 512 1024H409.6l256-614.4H768l256 614.4H921.6l-64-153.6H576zM618.496 768h196.608L716.8 532.48 618.496 768z"></path></svg><!--]--><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="route-link nav-link" href="/UserGuide/V1.0.x/Query-Data/Continuous-Query.html" aria-label="English"><!---->English<!----></a></li><li class="dropdown-item"><a class="route-link nav-link active" href="/zh/UserGuide/V1.0.x/Query-Data/Continuous-Query.html" aria-label="简体中文"><!---->简体中文<!----></a></li></ul></button></div></div><div class="vp-nav-item hide-in-mobile"><button type="button" id="appearance-switch"><svg xmlns="http://www.w3.org/2000/svg" class="icon auto-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="auto icon" style="display:none;"><path d="M512 992C246.92 992 32 777.08 32 512S246.92 32 512 32s480 214.92 480 480-214.92 480-480 480zm0-840c-198.78 0-360 161.22-360 360 0 198.84 161.22 360 360 360s360-161.16 360-360c0-198.78-161.22-360-360-360zm0 660V212c165.72 0 300 134.34 300 300 0 165.72-134.28 300-300 300z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="dark icon" style="display:none;"><path d="M524.8 938.667h-4.267a439.893 439.893 0 0 1-313.173-134.4 446.293 446.293 0 0 1-11.093-597.334A432.213 432.213 0 0 1 366.933 90.027a42.667 42.667 0 0 1 45.227 9.386 42.667 42.667 0 0 1 10.24 42.667 358.4 358.4 0 0 0 82.773 375.893 361.387 361.387 0 0 0 376.747 82.774 42.667 42.667 0 0 1 54.187 55.04 433.493 433.493 0 0 1-99.84 154.88 438.613 438.613 0 0 1-311.467 128z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="light icon" style="display:block;"><path d="M952 552h-80a40 40 0 0 1 0-80h80a40 40 0 0 1 0 80zM801.88 280.08a41 41 0 0 1-57.96-57.96l57.96-58a41.04 41.04 0 0 1 58 58l-58 57.96zM512 752a240 240 0 1 1 0-480 240 240 0 0 1 0 480zm0-560a40 40 0 0 1-40-40V72a40 40 0 0 1 80 0v80a40 40 0 0 1-40 40zm-289.88 88.08-58-57.96a41.04 41.04 0 0 1 58-58l57.96 58a41 41 0 0 1-57.96 57.96zM192 512a40 40 0 0 1-40 40H72a40 40 0 0 1 0-80h80a40 40 0 0 1 40 40zm30.12 231.92a41 41 0 0 1 57.96 57.96l-57.96 58a41.04 41.04 0 0 1-58-58l58-57.96zM512 832a40 40 0 0 1 40 40v80a40 40 0 0 1-80 0v-80a40 40 0 0 1 40-40zm289.88-88.08 58 57.96a41.04 41.04 0 0 1-58 58l-57.96-58a41 41 0 0 1 57.96-57.96z"></path></svg></button></div><div class="vp-nav-item vp-action"><a class="vp-action-link" href="https://github.com/apache/iotdb" target="_blank" rel="noopener noreferrer" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="icon github-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="github icon" style="width:1.25rem;height:1.25rem;vertical-align:middle;"><path d="M511.957 21.333C241.024 21.333 21.333 240.981 21.333 512c0 216.832 140.544 400.725 335.574 465.664 24.49 4.395 32.256-10.07 32.256-23.083 0-11.69.256-44.245 0-85.205-136.448 29.61-164.736-64.64-164.736-64.64-22.315-56.704-54.4-71.765-54.4-71.765-44.587-30.464 3.285-29.824 3.285-29.824 49.195 3.413 75.179 50.517 75.179 50.517 43.776 75.008 114.816 53.333 142.762 40.79 4.523-31.66 17.152-53.377 31.19-65.537-108.971-12.458-223.488-54.485-223.488-242.602 0-53.547 19.114-97.323 50.517-131.67-5.035-12.33-21.93-62.293 4.779-129.834 0 0 41.258-13.184 134.912 50.346a469.803 469.803 0 0 1 122.88-16.554c41.642.213 83.626 5.632 122.88 16.554 93.653-63.488 134.784-50.346 134.784-50.346 26.752 67.541 9.898 117.504 4.864 129.834 31.402 34.347 50.474 78.123 50.474 131.67 0 188.586-114.73 230.016-224.042 242.09 17.578 15.232 33.578 44.672 33.578 90.454v135.85c0 13.142 7.936 27.606 32.854 22.87C862.25 912.597 1002.667 728.747 1002.667 512c0-271.019-219.648-490.667-490.71-490.667z"></path></svg></a></div><!--]--><!--[--><!----><!--]--><button type="button" class="vp-toggle-navbar-button" aria-label="Toggle Navbar" aria-expanded="false" aria-controls="nav-screen"><span><span class="vp-top"></span><span class="vp-middle"></span><span class="vp-bottom"></span></span></button></div></header><!----><!--]--><!----><div class="toggle-sidebar-wrapper"><span class="arrow start"></span></div><aside id="sidebar" class="vp-sidebar"><!--[--><!----><!--]--><ul class="vp-sidebar-links"><li><section class="vp-sidebar-group"><p class="vp-sidebar-header"><!----><span class="vp-sidebar-title">IoTDB用户手册 (V1.0.x)</span><!----></p><ul class="vp-sidebar-links"></ul></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">关于IoTDB</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">快速上手</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据模式与概念</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">语法约定</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">应用编程接口</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">元数据操作</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据写入（数据更新）</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">数据删除</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable active" type="button"><!----><span class="vp-sidebar-title">数据查询</span><span class="vp-arrow down"></span></button><ul class="vp-sidebar-links"><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Overview.html" aria-label="概述"><!---->概述<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Select-Expression.html" aria-label="选择表达式"><!---->选择表达式<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Last-Query.html" aria-label="最新点查询"><!---->最新点查询<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Align-By.html" aria-label="查询对齐模式"><!---->查询对齐模式<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Where-Condition.html" aria-label="查询过滤条件"><!---->查询过滤条件<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Group-By.html" aria-label="分段分组聚合"><!---->分段分组聚合<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Having-Condition.html" aria-label="聚合结果过滤"><!---->聚合结果过滤<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Fill.html" aria-label="结果集补空值"><!---->结果集补空值<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Pagination.html" aria-label="结果集分页"><!---->结果集分页<!----></a></li><li><a class="route-link nav-link vp-sidebar-link vp-sidebar-page" href="/zh/UserGuide/V1.0.x/Query-Data/Select-Into.html" aria-label="查询写回"><!---->查询写回<!----></a></li><li><a class="route-link nav-link active vp-sidebar-link vp-sidebar-page active" href="/zh/UserGuide/V1.0.x/Query-Data/Continuous-Query.html" aria-label="连续查询"><!---->连续查询<!----></a></li></ul></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">运算符和函数</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">触发器</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">监控告警</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">权限管理</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">运维工具</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">端云协同</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">系统集成</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">分布式</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">FAQ</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-header clickable" type="button"><!----><span class="vp-sidebar-title">参考</span><span class="vp-arrow end"></span></button><!----></section></li></ul><!--[--><!----><!--]--></aside><!--[--><main id="main-content" class="vp-page"><!--[--><!--[--><!----><!--]--><!----><nav class="vp-breadcrumb disable"></nav><div class="vp-page-title"><h1><!---->连续查询（Continuous Query, CQ）</h1><div class="page-info"><!----><!----><span class="page-date-info" aria-label="写作日期"><svg xmlns="http://www.w3.org/2000/svg" class="icon calendar-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="calendar icon"><path d="M716.4 110.137c0-18.753-14.72-33.473-33.472-33.473-18.753 0-33.473 14.72-33.473 33.473v33.473h66.993v-33.473zm-334.87 0c0-18.753-14.72-33.473-33.473-33.473s-33.52 14.72-33.52 33.473v33.473h66.993v-33.473zm468.81 33.52H716.4v100.465c0 18.753-14.72 33.473-33.472 33.473a33.145 33.145 0 01-33.473-33.473V143.657H381.53v100.465c0 18.753-14.72 33.473-33.473 33.473a33.145 33.145 0 01-33.473-33.473V143.657H180.6A134.314 134.314 0 0046.66 277.595v535.756A134.314 134.314 0 00180.6 947.289h669.74a134.36 134.36 0 00133.94-133.938V277.595a134.314 134.314 0 00-133.94-133.938zm33.473 267.877H147.126a33.145 33.145 0 01-33.473-33.473c0-18.752 14.72-33.473 33.473-33.473h736.687c18.752 0 33.472 14.72 33.472 33.473a33.145 33.145 0 01-33.472 33.473z"></path></svg><span><!----></span><meta property="datePublished" content="2023-07-10T03:11:17.000Z"></span><span class="page-pageview-info" aria-label="访问量"><svg xmlns="http://www.w3.org/2000/svg" class="icon eye-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="eye icon"><path d="M992 512.096c0-5.76-.992-10.592-1.28-11.136-.192-2.88-1.152-8.064-2.08-10.816-.256-.672-.544-1.376-.832-2.08-.48-1.568-1.024-3.104-1.6-4.32C897.664 290.112 707.104 160 512 160c-195.072 0-385.632 130.016-473.76 322.592-1.056 2.112-1.792 4.096-2.272 5.856a55.512 55.512 0 00-.64 1.6c-1.76 5.088-1.792 8.64-1.632 7.744-.832 3.744-1.568 11.168-1.568 11.168-.224 2.272-.224 4.032.032 6.304 0 0 .736 6.464 1.088 7.808.128 1.824.576 4.512 1.12 6.976h-.032c.448 2.08 1.12 4.096 1.984 6.08.48 1.536.992 2.976 1.472 4.032C126.432 733.856 316.992 864 512 864c195.136 0 385.696-130.048 473.216-321.696 1.376-2.496 2.24-4.832 2.848-6.912.256-.608.48-1.184.672-1.728 1.536-4.48 1.856-8.32 1.728-8.32l-.032.032c.608-3.104 1.568-7.744 1.568-13.28zM512 672c-88.224 0-160-71.776-160-160s71.776-160 160-160 160 71.776 160 160-71.776 160-160 160z"></path></svg><span id="ArtalkPV" class="vp-pageview waline-pageview-count" data-path="/zh/UserGuide/V1.0.x/Query-Data/Continuous-Query.html" data-page-key="/zh/UserGuide/V1.0.x/Query-Data/Continuous-Query.html">...</span></span><span class="page-reading-time-info" aria-label="阅读时间"><svg xmlns="http://www.w3.org/2000/svg" class="icon timer-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="timer icon"><path d="M799.387 122.15c4.402-2.978 7.38-7.897 7.38-13.463v-1.165c0-8.933-7.38-16.312-16.312-16.312H256.33c-8.933 0-16.311 7.38-16.311 16.312v1.165c0 5.825 2.977 10.874 7.637 13.592 4.143 194.44 97.22 354.963 220.201 392.763-122.204 37.542-214.893 196.511-220.2 389.397-4.661 5.049-7.638 11.651-7.638 19.03v5.825h566.49v-5.825c0-7.379-2.849-13.981-7.509-18.9-5.049-193.016-97.867-351.985-220.2-389.527 123.24-37.67 216.446-198.453 220.588-392.892zM531.16 450.445v352.632c117.674 1.553 211.787 40.778 211.787 88.676H304.097c0-48.286 95.149-87.382 213.728-88.676V450.445c-93.077-3.107-167.901-81.297-167.901-177.093 0-8.803 6.99-15.793 15.793-15.793 8.803 0 15.794 6.99 15.794 15.793 0 80.261 63.69 145.635 142.01 145.635s142.011-65.374 142.011-145.635c0-8.803 6.99-15.793 15.794-15.793s15.793 6.99 15.793 15.793c0 95.019-73.789 172.82-165.96 177.093z"></path></svg><span>大约 17 分钟</span><meta property="timeRequired" content="PT17M"></span><!----><!----></div><hr></div><div class="vp-toc-placeholder"><aside id="toc"><!--[--><!----><!--]--><div class="vp-toc-header">此页内容<button type="button" class="print-button" title="打印"><svg xmlns="http://www.w3.org/2000/svg" class="icon print-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="print icon"><path d="M819.2 364.8h-44.8V128c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v236.8h-44.8C145.067 364.8 96 413.867 96 473.6v192c0 59.733 49.067 108.8 108.8 108.8h44.8V896c0 17.067 14.933 32 32 32h460.8c17.067 0 32-14.933 32-32V774.4h44.8c59.733 0 108.8-49.067 108.8-108.8v-192c0-59.733-49.067-108.8-108.8-108.8zM313.6 160h396.8v204.8H313.6V160zm396.8 704H313.6V620.8h396.8V864zM864 665.6c0 25.6-19.2 44.8-44.8 44.8h-44.8V588.8c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v121.6h-44.8c-25.6 0-44.8-19.2-44.8-44.8v-192c0-25.6 19.2-44.8 44.8-44.8h614.4c25.6 0 44.8 19.2 44.8 44.8v192z"></path></svg></button><div class="arrow end"></div></div><div class="vp-toc-wrapper"><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#简介">简介</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#语法">语法</a></li><li><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#连续查询语法中参数含义的描述">连续查询语法中参数含义的描述</a></li><!----><!--]--></ul></li><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#连续查询的用例">连续查询的用例</a></li><li><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#配置连续查询执行的周期性间隔">配置连续查询执行的周期性间隔</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#配置连续查询的时间窗口大小">配置连续查询的时间窗口大小</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#同时配置连续查询执行的周期性间隔和时间窗口大小">同时配置连续查询执行的周期性间隔和时间窗口大小</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#配置连续查询每次查询执行时间窗口的结束时间">配置连续查询每次查询执行时间窗口的结束时间</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#没有group-by-time子句的连续查询">没有GROUP BY TIME子句的连续查询</a></li><!----><!--]--></ul></li><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#连续查询的管理">连续查询的管理</a></li><li><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#查询系统已有的连续查询">查询系统已有的连续查询</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#删除已有的连续查询">删除已有的连续查询</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#修改已有的连续查询">修改已有的连续查询</a></li><!----><!--]--></ul></li><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#连续查询的使用场景">连续查询的使用场景</a></li><li><ul class="vp-toc-list"><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#对数据进行降采样并对降采样后的数据使用不同的保留策略">对数据进行降采样并对降采样后的数据使用不同的保留策略</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#预计算代价昂贵的查询">预计算代价昂贵的查询</a></li><!----><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level3" href="#作为子查询的替代品">作为子查询的替代品</a></li><!----><!--]--></ul></li><!--]--><!--[--><li class="vp-toc-item"><a class="route-link vp-toc-link level2" href="#连续查询相关的配置参数">连续查询相关的配置参数</a></li><!----><!--]--></ul><div class="vp-toc-marker" style="top:-1.7rem;"></div></div><!--[--><!----><!--]--></aside></div><!--[--><!----><!--]--><div class="theme-hope-content"><h1 id="连续查询-continuous-query-cq" tabindex="-1"><a class="header-anchor" href="#连续查询-continuous-query-cq"><span>连续查询（Continuous Query, CQ）</span></a></h1><h2 id="简介" tabindex="-1"><a class="header-anchor" href="#简介"><span>简介</span></a></h2><p>连续查询(Continuous queries, aka CQ) 是对实时数据周期性地自动执行的查询，并将查询结果写入指定的时间序列中。</p><h2 id="语法" tabindex="-1"><a class="header-anchor" href="#语法"><span>语法</span></a></h2><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> <span class="token punctuation">(</span>CONTINUOUS QUERY <span class="token operator">|</span> CQ<span class="token punctuation">)</span> <span class="token operator"><</span>cq_id<span class="token operator">></span> |
| <span class="token punctuation">[</span>RESAMPLE |
| <span class="token punctuation">[</span>EVERY <span class="token operator"><</span>every_interval<span class="token operator">></span><span class="token punctuation">]</span> |
| <span class="token punctuation">[</span>BOUNDARY <span class="token operator"><</span>execution_boundary_time<span class="token operator">></span><span class="token punctuation">]</span> |
| <span class="token punctuation">[</span>RANGE <span class="token operator"><</span>start_time_offset<span class="token operator">></span><span class="token punctuation">[</span><span class="token punctuation">,</span> end_time_offset<span class="token punctuation">]</span><span class="token punctuation">]</span> |
| <span class="token punctuation">]</span> |
| <span class="token punctuation">[</span>TIMEOUT POLICY BLOCKED<span class="token operator">|</span><span class="token keyword">DISCARD</span><span class="token punctuation">]</span> |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> CLAUSE |
| <span class="token keyword">INTO</span> CLAUSE |
| <span class="token keyword">FROM</span> CLAUSE |
| <span class="token punctuation">[</span><span class="token keyword">WHERE</span> CLAUSE<span class="token punctuation">]</span> |
| <span class="token punctuation">[</span><span class="token keyword">GROUP</span> <span class="token keyword">BY</span><span class="token punctuation">(</span><span class="token operator"><</span>group_by_interval<span class="token operator">></span><span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token operator"><</span>sliding_step<span class="token operator">></span><span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token keyword">level</span> <span class="token operator">=</span> <span class="token operator"><</span><span class="token keyword">level</span><span class="token operator">></span><span class="token punctuation">]</span><span class="token punctuation">]</span> |
| <span class="token punctuation">[</span><span class="token keyword">HAVING</span> CLAUSE<span class="token punctuation">]</span> |
| <span class="token punctuation">[</span>FILL {PREVIOUS <span class="token operator">|</span> LINEAR <span class="token operator">|</span> constant}<span class="token punctuation">]</span> |
| <span class="token punctuation">[</span><span class="token keyword">LIMIT</span> rowLimit <span class="token keyword">OFFSET</span> rowOffset<span class="token punctuation">]</span> |
| <span class="token punctuation">[</span>ALIGN <span class="token keyword">BY</span> DEVICE<span class="token punctuation">]</span> |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><blockquote><p>注意：</p><ol><li>如果where子句中出现任何时间过滤条件，IoTDB将会抛出异常，因为IoTDB会自动为每次查询执行指定时间范围。</li><li>GROUP BY TIME CLAUSE在连续查询中的语法稍有不同，它不能包含原来的第一个参数，即 [start_time, end_time)，IoTDB会自动填充这个缺失的参数。如果指定，IoTDB将会抛出异常。</li><li>如果连续查询中既没有GROUP BY TIME子句，也没有指定EVERY子句，IoTDB将会抛出异常。</li></ol></blockquote><h3 id="连续查询语法中参数含义的描述" tabindex="-1"><a class="header-anchor" href="#连续查询语法中参数含义的描述"><span>连续查询语法中参数含义的描述</span></a></h3><ul><li><code><cq_id></code> 为连续查询指定一个全局唯一的标识。</li><li><code><every_interval></code> 指定了连续查询周期性执行的间隔。现在支持的时间单位有：ns, us, ms, s, m, h, d, w, 并且它的值不能小于用户在<code>iotdb-confignode.properties</code>配置文件中指定的<code>continuous_query_min_every_interval</code>。这是一个可选参数，默认等于group by子句中的<code>group_by_interval</code>。</li><li><code><start_time_offset></code> 指定了每次查询执行窗口的开始时间，即<code>now()-<start_time_offset></code>。现在支持的时间单位有：ns, us, ms, s, m, h, d, w。这是一个可选参数，默认等于<code>EVERY</code>子句中的<code>every_interval</code>。</li><li><code><end_time_offset></code> 指定了每次查询执行窗口的结束时间，即<code>now()-<end_time_offset></code>。现在支持的时间单位有：ns, us, ms, s, m, h, d, w。这是一个可选参数，默认等于<code>0</code>.</li><li><code><execution_boundary_time></code> 表示用户期待的连续查询的首个周期任务的执行时间。（因为连续查询只会对当前实时的数据流做计算，所以该连续查询实际首个周期任务的执行时间并不一定等于用户指定的时间，具体计算逻辑如下所示） <ul><li><code><execution_boundary_time></code> 可以早于、等于或者迟于当前时间。</li><li>这个参数是可选的，默认等于<code>0</code>。</li><li>首次查询执行窗口的开始时间为<code><execution_boundary_time> - <start_time_offset></code>.</li><li>首次查询执行窗口的结束时间为<code><execution_boundary_time> - <end_time_offset></code>.</li><li>第i个查询执行窗口的时间范围是<code>[<execution_boundary_time> - <start_time_offset> + (i - 1) * <every_interval>, <execution_boundary_time> - <end_time_offset> + (i - 1) * <every_interval>)</code>。</li><li>如果当前时间早于或等于, 那连续查询的首个周期任务的执行时间就是用户指定的<code>execution_boundary_time</code>.</li><li>如果当前时间迟于用户指定的<code>execution_boundary_time</code>，那么连续查询的首个周期任务的执行时间就是<code>execution_boundary_time + i * <every_interval></code>中第一个大于或等于当前时间的值。</li></ul></li></ul><blockquote><ul><li><every_interval>，<start_time_offset> 和 <group_by_interval> 都应该大于 0</li><li><group_by_interval>应该小于等于<start_time_offset></li><li>用户应该根据实际需求，为<start_time_offset> 和 <every_interval> 指定合适的值 <ul><li>如果<start_time_offset>大于<every_interval>，在每一次查询执行的时间窗口上会有部分重叠</li><li>如果<start_time_offset>小于<every_interval>，在连续的两次查询执行的时间窗口中间将会有未覆盖的时间范围</li></ul></li><li>start_time_offset 应该大于end_time_offset</li></ul></blockquote><h4 id="start-time-offset-等于-every-interval" tabindex="-1"><a class="header-anchor" href="#start-time-offset-等于-every-interval"><span><code><start_time_offset></code>等于<code><every_interval></code></span></a></h4><figure><img src="https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic1.png?raw=true" alt="1" tabindex="0" loading="lazy"><figcaption>1</figcaption></figure><h4 id="start-time-offset-大于-every-interval" tabindex="-1"><a class="header-anchor" href="#start-time-offset-大于-every-interval"><span><code><start_time_offset></code>大于<code><every_interval></code></span></a></h4><figure><img src="https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic2.png?raw=true" alt="2" tabindex="0" loading="lazy"><figcaption>2</figcaption></figure><h4 id="start-time-offset-小于-every-interval" tabindex="-1"><a class="header-anchor" href="#start-time-offset-小于-every-interval"><span><code><start_time_offset></code>小于<code><every_interval></code></span></a></h4><figure><img src="https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic3.png?raw=true" alt="3" tabindex="0" loading="lazy"><figcaption>3</figcaption></figure><h4 id="every-interval-不为0" tabindex="-1"><a class="header-anchor" href="#every-interval-不为0"><span><code><every_interval></code>不为0</span></a></h4><figure><img src="https://alioss.timecho.com/docs/img/UserGuide/Process-Data/Continuous-Query/pic4.png?raw=true" alt="4" tabindex="0" loading="lazy"><figcaption>4</figcaption></figure><ul><li><code>TIMEOUT POLICY</code> 指定了我们如何处理“前一个时间窗口还未执行完时，下一个窗口的执行时间已经到达的场景，默认值是<code>BLOCKED</code>. <ul><li><code>BLOCKED</code>意味着即使下一个窗口的执行时间已经到达，我们依旧需要阻塞等待前一个时间窗口的查询执行完再开始执行下一个窗口。如果使用<code>BLOCKED</code>策略，所有的时间窗口都将会被依此执行，但是如果遇到执行查询的时间长于周期性间隔时，连续查询的结果会迟于最新的时间窗口范围。</li><li><code>DISCARD</code>意味着如果前一个时间窗口还未执行完，我们会直接丢弃下一个窗口的执行时间。如果使用<code>DISCARD</code>策略，可能会有部分时间窗口得不到执行。但是一旦前一个查询执行完后，它将会使用最新的时间窗口，所以它的执行结果总能赶上最新的时间窗口范围，当然是以部分时间窗口得不到执行为代价。</li></ul></li></ul><h2 id="连续查询的用例" tabindex="-1"><a class="header-anchor" href="#连续查询的用例"><span>连续查询的用例</span></a></h2><p>下面是用例数据，这是一个实时的数据流，我们假设数据都按时到达。</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>+-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+ |
| | Time|root.ln.wf02.wt02.temperature|root.ln.wf02.wt01.temperature|root.ln.wf01.wt02.temperature|root.ln.wf01.wt01.temperature| |
| +-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+ |
| |2021-05-11T22:18:14.598+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:19.941+08:00| 0.0| 68.0| 68.0| 103.0| |
| |2021-05-11T22:18:24.949+08:00| 122.0| 45.0| 11.0| 14.0| |
| |2021-05-11T22:18:29.967+08:00| 47.0| 14.0| 59.0| 181.0| |
| |2021-05-11T22:18:34.979+08:00| 182.0| 113.0| 29.0| 180.0| |
| |2021-05-11T22:18:39.990+08:00| 42.0| 11.0| 52.0| 19.0| |
| |2021-05-11T22:18:44.995+08:00| 78.0| 38.0| 123.0| 52.0| |
| |2021-05-11T22:18:49.999+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:55.003+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+-----------------------------+-----------------------------+-----------------------------+-----------------------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="配置连续查询执行的周期性间隔" tabindex="-1"><a class="header-anchor" href="#配置连续查询执行的周期性间隔"><span>配置连续查询执行的周期性间隔</span></a></h3><p>在<code>RESAMPLE</code>子句中使用<code>EVERY</code>参数指定连续查询的执行间隔，如果没有指定，默认等于<code>group_by_interval</code>。</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> CONTINUOUS QUERY cq1 |
| RESAMPLE EVERY <span class="token number">20</span>s |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> max_value<span class="token punctuation">(</span>temperature<span class="token punctuation">)</span> |
| <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span> |
| <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span><span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> |
| <span class="token keyword">GROUP</span> <span class="token keyword">BY</span><span class="token punctuation">(</span><span class="token number">10</span>s<span class="token punctuation">)</span> |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq1</code>计算出<code>temperature</code>传感器每10秒的平均值，并且将查询结果存储在<code>temperature_max</code>传感器下，传感器路径前缀使用跟原来一样的前缀。</p><p><code>cq1</code>每20秒执行一次，每次执行的查询的时间窗口范围是从过去20秒到当前时间。</p><p>假设当前时间是<code>2021-05-11T22:18:40.000+08:00</code>，如果把日志等级设置为DEBUG，我们可以在<code>cq1</code>执行的DataNode上看到如下的输出：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>At **2021-05-11T22:18:40.000+08:00**, `cq1` executes a query within the time range `[2021-05-11T22:18:20, 2021-05-11T22:18:40)`. |
| `cq1` generate 2 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| At **2021-05-11T22:19:00.000+08:00**, `cq1` executes a query within the time range `[2021-05-11T22:18:40, 2021-05-11T22:19:00)`. |
| `cq1` generate 2 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:50.000+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq1</code>并不会处理当前时间窗口以外的数据，即<code>2021-05-11T22:18:20.000+08:00</code>以前的数据，所以我们会得到如下结果：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>> SELECT temperature_max from root.ln.*.*; |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:50.000+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="配置连续查询的时间窗口大小" tabindex="-1"><a class="header-anchor" href="#配置连续查询的时间窗口大小"><span>配置连续查询的时间窗口大小</span></a></h3><p>使用<code>RANGE</code>子句中的<code>start_time_offset</code>参数指定连续查询每次执行的时间窗口的开始时间偏移，如果没有指定，默认值等于<code>EVERY</code>参数。</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> CONTINUOUS QUERY cq2 |
| RESAMPLE RANGE <span class="token number">40</span>s |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> max_value<span class="token punctuation">(</span>temperature<span class="token punctuation">)</span> |
| <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span> |
| <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span><span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> |
| <span class="token keyword">GROUP</span> <span class="token keyword">BY</span><span class="token punctuation">(</span><span class="token number">10</span>s<span class="token punctuation">)</span> |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq2</code>计算出<code>temperature</code>传感器每10秒的平均值，并且将查询结果存储在<code>temperature_max</code>传感器下，传感器路径前缀使用跟原来一样的前缀。</p><p><code>cq2</code>每10秒执行一次，每次执行的查询的时间窗口范围是从过去40秒到当前时间。</p><p>假设当前时间是<code>2021-05-11T22:18:40.000+08:00</code>，如果把日志等级设置为DEBUG，我们可以在<code>cq2</code>执行的DataNode上看到如下的输出：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>At **2021-05-11T22:18:40.000+08:00**, `cq2` executes a query within the time range `[2021-05-11T22:18:00, 2021-05-11T22:18:40)`. |
| `cq2` generate 4 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:00.000+08:00| NULL| NULL| NULL| NULL| |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| At **2021-05-11T22:18:50.000+08:00**, `cq2` executes a query within the time range `[2021-05-11T22:18:10, 2021-05-11T22:18:50)`. |
| `cq2` generate 4 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| At **2021-05-11T22:19:00.000+08:00**, `cq2` executes a query within the time range `[2021-05-11T22:18:20, 2021-05-11T22:19:00)`. |
| `cq2` generate 4 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:50.000+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq2</code>并不会写入全是null值的行，值得注意的是<code>cq2</code>会多次计算某些区间的聚合值，下面是计算结果：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>> SELECT temperature_max from root.ln.*.*; |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:50.000+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="同时配置连续查询执行的周期性间隔和时间窗口大小" tabindex="-1"><a class="header-anchor" href="#同时配置连续查询执行的周期性间隔和时间窗口大小"><span>同时配置连续查询执行的周期性间隔和时间窗口大小</span></a></h3><p>使用<code>RESAMPLE</code>子句中的<code>EVERY</code>参数和<code>RANGE</code>参数分别指定连续查询的执行间隔和窗口大小。并且使用<code>fill()</code>来填充没有值的时间区间。</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> CONTINUOUS QUERY cq3 |
| RESAMPLE EVERY <span class="token number">20</span>s RANGE <span class="token number">40</span>s |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> max_value<span class="token punctuation">(</span>temperature<span class="token punctuation">)</span> |
| <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span> |
| <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span><span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> |
| <span class="token keyword">GROUP</span> <span class="token keyword">BY</span><span class="token punctuation">(</span><span class="token number">10</span>s<span class="token punctuation">)</span> |
| FILL<span class="token punctuation">(</span><span class="token number">100.0</span><span class="token punctuation">)</span> |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq3</code>计算出<code>temperature</code>传感器每10秒的平均值，并且将查询结果存储在<code>temperature_max</code>传感器下，传感器路径前缀使用跟原来一样的前缀。如果某些区间没有值，用<code>100.0</code>填充。</p><p><code>cq3</code>每20秒执行一次，每次执行的查询的时间窗口范围是从过去40秒到当前时间。</p><p>假设当前时间是<code>2021-05-11T22:18:40.000+08:00</code>，如果把日志等级设置为DEBUG，我们可以在<code>cq3</code>执行的DataNode上看到如下的输出：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>At **2021-05-11T22:18:40.000+08:00**, `cq3` executes a query within the time range `[2021-05-11T22:18:00, 2021-05-11T22:18:40)`. |
| `cq3` generate 4 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:00.000+08:00| 100.0| 100.0| 100.0| 100.0| |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| At **2021-05-11T22:19:00.000+08:00**, `cq3` executes a query within the time range `[2021-05-11T22:18:20, 2021-05-11T22:19:00)`. |
| `cq3` generate 4 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:50.000+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>值得注意的是<code>cq3</code>会多次计算某些区间的聚合值，下面是计算结果：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>> SELECT temperature_max from root.ln.*.*; |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:00.000+08:00| 100.0| 100.0| 100.0| 100.0| |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| |2021-05-11T22:18:40.000+08:00| 137.0| 172.0| 135.0| 193.0| |
| |2021-05-11T22:18:50.000+08:00| 16.0| 124.0| 183.0| 18.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="配置连续查询每次查询执行时间窗口的结束时间" tabindex="-1"><a class="header-anchor" href="#配置连续查询每次查询执行时间窗口的结束时间"><span>配置连续查询每次查询执行时间窗口的结束时间</span></a></h3><p>使用<code>RESAMPLE</code>子句中的<code>EVERY</code>参数和<code>RANGE</code>参数分别指定连续查询的执行间隔和窗口大小。并且使用<code>fill()</code>来填充没有值的时间区间。</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> CONTINUOUS QUERY cq4 |
| RESAMPLE EVERY <span class="token number">20</span>s RANGE <span class="token number">40</span>s<span class="token punctuation">,</span> <span class="token number">20</span>s |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> max_value<span class="token punctuation">(</span>temperature<span class="token punctuation">)</span> |
| <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf02<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt02<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span><span class="token punctuation">,</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>wf01<span class="token punctuation">.</span>wt01<span class="token punctuation">(</span>temperature_max<span class="token punctuation">)</span> |
| <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span><span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> |
| <span class="token keyword">GROUP</span> <span class="token keyword">BY</span><span class="token punctuation">(</span><span class="token number">10</span>s<span class="token punctuation">)</span> |
| FILL<span class="token punctuation">(</span><span class="token number">100.0</span><span class="token punctuation">)</span> |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq4</code>计算出<code>temperature</code>传感器每10秒的平均值，并且将查询结果存储在<code>temperature_max</code>传感器下，传感器路径前缀使用跟原来一样的前缀。如果某些区间没有值，用<code>100.0</code>填充。</p><p><code>cq4</code>每20秒执行一次，每次执行的查询的时间窗口范围是从过去40秒到过去20秒。</p><p>假设当前时间是<code>2021-05-11T22:18:40.000+08:00</code>，如果把日志等级设置为DEBUG，我们可以在<code>cq4</code>执行的DataNode上看到如下的输出：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>At **2021-05-11T22:18:40.000+08:00**, `cq4` executes a query within the time range `[2021-05-11T22:18:00, 2021-05-11T22:18:20)`. |
| `cq4` generate 2 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:00.000+08:00| 100.0| 100.0| 100.0| 100.0| |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| At **2021-05-11T22:19:00.000+08:00**, `cq4` executes a query within the time range `[2021-05-11T22:18:20, 2021-05-11T22:18:40)`. |
| `cq4` generate 2 lines: |
| > |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| > |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>值得注意的是<code>cq4</code>只会计算每个聚合区间一次，并且每次开始执行计算的时间都会比当前的时间窗口结束时间迟20s, 下面是计算结果：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>> SELECT temperature_max from root.ln.*.*; |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| | Time|root.ln.wf02.wt02.temperature_max|root.ln.wf02.wt01.temperature_max|root.ln.wf01.wt02.temperature_max|root.ln.wf01.wt01.temperature_max| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| |2021-05-11T22:18:00.000+08:00| 100.0| 100.0| 100.0| 100.0| |
| |2021-05-11T22:18:10.000+08:00| 121.0| 72.0| 183.0| 115.0| |
| |2021-05-11T22:18:20.000+08:00| 122.0| 45.0| 59.0| 181.0| |
| |2021-05-11T22:18:30.000+08:00| 182.0| 113.0| 52.0| 180.0| |
| +-----------------------------+---------------------------------+---------------------------------+---------------------------------+---------------------------------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="没有group-by-time子句的连续查询" tabindex="-1"><a class="header-anchor" href="#没有group-by-time子句的连续查询"><span>没有GROUP BY TIME子句的连续查询</span></a></h3><p>不使用<code>GROUP BY TIME</code>子句，并在<code>RESAMPLE</code>子句中显式使用<code>EVERY</code>参数指定连续查询的执行间隔。</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> CONTINUOUS QUERY cq5 |
| RESAMPLE EVERY <span class="token number">20</span>s |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> temperature <span class="token operator">+</span> <span class="token number">1</span> |
| <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>precalculated_sg<span class="token punctuation">.</span>::<span class="token punctuation">(</span>temperature<span class="token punctuation">)</span> |
| <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span><span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> |
| align <span class="token keyword">by</span> device |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq5</code>计算以<code>root.ln</code>为前缀的所有<code>temperature + 1</code>的值，并将结果储存在另一个 database <code>root.precalculated_sg</code>中。除 database 名称不同外，目标序列与源序列路径名均相同。</p><p><code>cq5</code>每20秒执行一次，每次执行的查询的时间窗口范围是从过去20秒到当前时间。</p><p>假设当前时间是<code>2021-05-11T22:18:40.000+08:00</code>，如果把日志等级设置为DEBUG，我们可以在<code>cq5</code>执行的DataNode上看到如下的输出：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>At **2021-05-11T22:18:40.000+08:00**, `cq5` executes a query within the time range `[2021-05-11T22:18:20, 2021-05-11T22:18:40)`. |
| `cq5` generate 16 lines: |
| > |
| +-----------------------------+-------------------------------+-----------+ |
| | Time| Device|temperature| |
| +-----------------------------+-------------------------------+-----------+ |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf02.wt02| 123.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf02.wt02| 48.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf02.wt02| 183.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf02.wt02| 45.0| |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf02.wt01| 46.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf02.wt01| 15.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf02.wt01| 114.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf02.wt01| 12.0| |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf01.wt02| 12.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf01.wt02| 60.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf01.wt02| 30.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf01.wt02| 53.0| |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf01.wt01| 15.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf01.wt01| 182.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf01.wt01| 181.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf01.wt01| 20.0| |
| +-----------------------------+-------------------------------+-----------+ |
| > |
| At **2021-05-11T22:19:00.000+08:00**, `cq5` executes a query within the time range `[2021-05-11T22:18:40, 2021-05-11T22:19:00)`. |
| `cq5` generate 12 lines: |
| > |
| +-----------------------------+-------------------------------+-----------+ |
| | Time| Device|temperature| |
| +-----------------------------+-------------------------------+-----------+ |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf02.wt02| 79.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf02.wt02| 138.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf02.wt02| 17.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf02.wt01| 39.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf02.wt01| 173.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf02.wt01| 125.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf01.wt02| 124.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf01.wt02| 136.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf01.wt02| 184.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf01.wt01| 53.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf01.wt01| 194.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf01.wt01| 19.0| |
| +-----------------------------+-------------------------------+-----------+ |
| > |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><code>cq5</code>并不会处理当前时间窗口以外的数据，即<code>2021-05-11T22:18:20.000+08:00</code>以前的数据，所以我们会得到如下结果：</p><div class="language-text line-numbers-mode" data-ext="text" data-title="text"><pre class="language-text"><code>> SELECT temperature from root.precalculated_sg.*.* align by device; |
| +-----------------------------+-------------------------------+-----------+ |
| | Time| Device|temperature| |
| +-----------------------------+-------------------------------+-----------+ |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf02.wt02| 123.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf02.wt02| 48.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf02.wt02| 183.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf02.wt02| 45.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf02.wt02| 79.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf02.wt02| 138.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf02.wt02| 17.0| |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf02.wt01| 46.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf02.wt01| 15.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf02.wt01| 114.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf02.wt01| 12.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf02.wt01| 39.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf02.wt01| 173.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf02.wt01| 125.0| |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf01.wt02| 12.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf01.wt02| 60.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf01.wt02| 30.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf01.wt02| 53.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf01.wt02| 124.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf01.wt02| 136.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf01.wt02| 184.0| |
| |2021-05-11T22:18:24.949+08:00|root.precalculated_sg.wf01.wt01| 15.0| |
| |2021-05-11T22:18:29.967+08:00|root.precalculated_sg.wf01.wt01| 182.0| |
| |2021-05-11T22:18:34.979+08:00|root.precalculated_sg.wf01.wt01| 181.0| |
| |2021-05-11T22:18:39.990+08:00|root.precalculated_sg.wf01.wt01| 20.0| |
| |2021-05-11T22:18:44.995+08:00|root.precalculated_sg.wf01.wt01| 53.0| |
| |2021-05-11T22:18:49.999+08:00|root.precalculated_sg.wf01.wt01| 194.0| |
| |2021-05-11T22:18:55.003+08:00|root.precalculated_sg.wf01.wt01| 19.0| |
| +-----------------------------+-------------------------------+-----------+ |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h2 id="连续查询的管理" tabindex="-1"><a class="header-anchor" href="#连续查询的管理"><span>连续查询的管理</span></a></h2><h3 id="查询系统已有的连续查询" tabindex="-1"><a class="header-anchor" href="#查询系统已有的连续查询"><span>查询系统已有的连续查询</span></a></h3><p>展示集群中所有的已注册的连续查询</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">SHOW</span> <span class="token punctuation">(</span>CONTINUOUS QUERIES <span class="token operator">|</span> CQS<span class="token punctuation">)</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p><code>SHOW (CONTINUOUS QUERIES | CQS)</code>会将结果集按照<code>cq_id</code>排序。</p><h4 id="例子" tabindex="-1"><a class="header-anchor" href="#例子"><span>例子</span></a></h4><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">SHOW</span> CONTINUOUS QUERIES<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>执行以上sql，我们将会得到如下的查询结果：</p><table><thead><tr><th style="text-align:left;">cq_id</th><th>query</th><th>state</th></tr></thead><tbody><tr><td style="text-align:left;">s1_count_cq</td><td>CREATE CQ s1_count_cq<br>BEGIN<br>SELECT count(s1)<br>INTO root.sg_count.d.count_s1<br>FROM root.sg.d<br>GROUP BY(30m)<br>END</td><td>active</td></tr></tbody></table><h3 id="删除已有的连续查询" tabindex="-1"><a class="header-anchor" href="#删除已有的连续查询"><span>删除已有的连续查询</span></a></h3><p>删除指定的名为cq_id的连续查询：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">DROP</span> <span class="token punctuation">(</span>CONTINUOUS QUERY <span class="token operator">|</span> CQ<span class="token punctuation">)</span> <span class="token operator"><</span>cq_id<span class="token operator">></span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>DROP CQ并不会返回任何结果集。</p><h4 id="例子-1" tabindex="-1"><a class="header-anchor" href="#例子-1"><span>例子</span></a></h4><p>删除名为s1_count_cq的连续查询：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">DROP</span> CONTINUOUS QUERY s1_count_cq<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h3 id="修改已有的连续查询" tabindex="-1"><a class="header-anchor" href="#修改已有的连续查询"><span>修改已有的连续查询</span></a></h3><p>目前连续查询一旦被创建就不能再被修改。如果想要修改某个连续查询，只能先用<code>DROP</code>命令删除它，然后再用<code>CREATE</code>命令重新创建。</p><h2 id="连续查询的使用场景" tabindex="-1"><a class="header-anchor" href="#连续查询的使用场景"><span>连续查询的使用场景</span></a></h2><h3 id="对数据进行降采样并对降采样后的数据使用不同的保留策略" tabindex="-1"><a class="header-anchor" href="#对数据进行降采样并对降采样后的数据使用不同的保留策略"><span>对数据进行降采样并对降采样后的数据使用不同的保留策略</span></a></h3><p>可以使用连续查询，定期将高频率采样的原始数据（如每秒1000个点），降采样（如每秒仅保留一个点）后保存到另一个 database 的同名序列中。高精度的原始数据所在 database 的<code>TTL</code>可能设置的比较短，比如一天，而低精度的降采样后的数据所在的 database <code>TTL</code>可以设置的比较长，比如一个月，从而达到快速释放磁盘空间的目的。</p><h3 id="预计算代价昂贵的查询" tabindex="-1"><a class="header-anchor" href="#预计算代价昂贵的查询"><span>预计算代价昂贵的查询</span></a></h3><p>我们可以通过连续查询对一些重复的查询进行预计算，并将查询结果保存在某些目标序列中，这样真实查询并不需要真的再次去做计算，而是直接查询目标序列的结果，从而缩短了查询的时间。</p><blockquote><p>预计算查询结果尤其对一些可视化工具渲染时序图和工作台时有很大的加速作用。</p></blockquote><h3 id="作为子查询的替代品" tabindex="-1"><a class="header-anchor" href="#作为子查询的替代品"><span>作为子查询的替代品</span></a></h3><p>IoTDB现在不支持子查询，但是我们可以通过创建连续查询得到相似的功能。我们可以将子查询注册为一个连续查询，并将子查询的结果物化到目标序列中，外层查询再直接查询哪个目标序列。</p><h4 id="例子-2" tabindex="-1"><a class="header-anchor" href="#例子-2"><span>例子</span></a></h4><p>IoTDB并不会接收如下的嵌套子查询。这个查询会计算s1序列每隔30分钟的非空值数量的平均值：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">SELECT</span> <span class="token function">avg</span><span class="token punctuation">(</span>count_s1<span class="token punctuation">)</span> <span class="token keyword">from</span> <span class="token punctuation">(</span><span class="token keyword">select</span> <span class="token function">count</span><span class="token punctuation">(</span>s1<span class="token punctuation">)</span> <span class="token keyword">as</span> count_s1 <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg<span class="token punctuation">.</span>d <span class="token keyword">group</span> <span class="token keyword">by</span><span class="token punctuation">(</span><span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token function">now</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token number">30</span>m<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>为了得到相同的结果，我们可以：</p><p><strong>1. 创建一个连续查询</strong></p><p>这一步执行内层子查询部分。下面创建的连续查询每隔30分钟计算一次<code>root.sg.d.s1</code>序列的非空值数量，并将结果写入目标序列<code>root.sg_count.d.count_s1</code>中。</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">CREATE</span> CQ s1_count_cq |
| <span class="token keyword">BEGIN</span> |
| <span class="token keyword">SELECT</span> <span class="token function">count</span><span class="token punctuation">(</span>s1<span class="token punctuation">)</span> |
| <span class="token keyword">INTO</span> root<span class="token punctuation">.</span>sg_count<span class="token punctuation">.</span>d<span class="token punctuation">.</span>count_s1 |
| <span class="token keyword">FROM</span> root<span class="token punctuation">.</span>sg<span class="token punctuation">.</span>d |
| <span class="token keyword">GROUP</span> <span class="token keyword">BY</span><span class="token punctuation">(</span><span class="token number">30</span>m<span class="token punctuation">)</span> |
| <span class="token keyword">END</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><strong>2. 查询连续查询的结果</strong></p><p>这一步执行外层查询的avg([...])部分。</p><p>查询序列<code>root.sg_count.d.count_s1</code>的值，并计算平均值：</p><div class="language-sql line-numbers-mode" data-ext="sql" data-title="sql"><pre class="language-sql"><code><span class="token keyword">SELECT</span> <span class="token function">avg</span><span class="token punctuation">(</span>count_s1<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>sg_count<span class="token punctuation">.</span>d<span class="token punctuation">;</span> |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h2 id="连续查询相关的配置参数" tabindex="-1"><a class="header-anchor" href="#连续查询相关的配置参数"><span>连续查询相关的配置参数</span></a></h2><table><thead><tr><th style="text-align:left;">参数名</th><th>描述</th><th>类型</th><th>默认值</th></tr></thead><tbody><tr><td style="text-align:left;"><code>continuous_query_submit_thread</code></td><td>用于周期性提交连续查询执行任务的线程数</td><td>int32</td><td>2</td></tr><tr><td style="text-align:left;"><code>continuous_query_min_every_interval_in_ms</code></td><td>系统允许的连续查询最小的周期性时间间隔</td><td>duration</td><td>1000</td></tr></tbody></table></div><!--[--><!----><!--]--><footer class="vp-page-meta"><div class="vp-meta-item edit-link"><a href="https://github.com/apache/iotdb-docs/edit/main/src/zh/UserGuide/V1.0.x/Query-Data/Continuous-Query.md" rel="noopener noreferrer" target="_blank" aria-label="发现错误？在 GitHub 上编辑此页" class="nav-link vp-meta-label"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon edit-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="edit icon"><path d="M430.818 653.65a60.46 60.46 0 0 1-50.96-93.281l71.69-114.012 7.773-10.365L816.038 80.138A60.46 60.46 0 0 1 859.225 62a60.46 60.46 0 0 1 43.186 18.138l43.186 43.186a60.46 60.46 0 0 1 0 86.373L588.879 565.55l-8.637 8.637-117.466 68.234a60.46 60.46 0 0 1-31.958 11.229z"></path><path d="M728.802 962H252.891A190.883 190.883 0 0 1 62.008 771.98V296.934a190.883 190.883 0 0 1 190.883-192.61h267.754a60.46 60.46 0 0 1 0 120.92H252.891a69.962 69.962 0 0 0-69.098 69.099V771.98a69.962 69.962 0 0 0 69.098 69.098h475.911A69.962 69.962 0 0 0 797.9 771.98V503.363a60.46 60.46 0 1 1 120.922 0V771.98A190.883 190.883 0 0 1 728.802 962z"></path></svg><!--]-->发现错误？在 GitHub 上编辑此页<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="vp-meta-item git-info"><div class="update-time"><span class="vp-meta-label">上次编辑于: </span><!----></div><!----></div></footer><nav class="vp-page-nav"><a class="route-link nav-link prev" href="/zh/UserGuide/V1.0.x/Query-Data/Select-Into.html" aria-label="查询写回"><div class="hint"><span class="arrow start"></span>上一页</div><div class="link"><!---->查询写回</div></a><!----></nav><!----><!--[--><!----><!--]--><!--]--></main><!--]--><footer style="padding-bottom:2rem;"><span id="doc-version" style="display:none;">rel/1.0</span><p style="text-align:center;color:#909399;font-size:12px;margin:0 30px;">Copyright © 2024 The Apache Software Foundation.<br> Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"><strong>Have a question?</strong> Connect with us on QQ, WeChat, or Slack. <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> now.</p></footer></div><!--]--><!--]--><!--[--><!----><!--]--><!--]--></div> |
| <script type="module" src="/assets/app-DrPcRZG6.js" defer></script> |
| </body> |
| </html> |
