| <!DOCTYPE html> |
| <html lang="zh-CN"> |
| <head> |
| <meta charset="utf-8"> |
| <meta name="viewport" content="width=device-width,initial-scale=1"> |
| <title> </title> |
| <meta name="generator" content="VuePress 1.8.2"> |
| <link rel="icon" href="/favicon.ico"> |
| <meta name="description" content=" "> |
| <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"> |
| |
| <link rel="preload" href="/assets/css/0.styles.ccadf850.css" as="style"><link rel="preload" href="/assets/js/app.c078fe6d.js" as="script"><link rel="preload" href="/assets/js/3.5626571b.js" as="script"><link rel="preload" href="/assets/js/292.2ee40b66.js" as="script"><link rel="prefetch" href="/assets/js/10.77e7d27b.js"><link rel="prefetch" href="/assets/js/100.ed95c785.js"><link rel="prefetch" href="/assets/js/101.a72c7dae.js"><link rel="prefetch" href="/assets/js/102.8c0e7138.js"><link rel="prefetch" href="/assets/js/103.5753f058.js"><link rel="prefetch" href="/assets/js/104.194a7259.js"><link rel="prefetch" href="/assets/js/105.09df4ac9.js"><link rel="prefetch" href="/assets/js/106.094ff7f6.js"><link rel="prefetch" href="/assets/js/107.4b6fc970.js"><link rel="prefetch" href="/assets/js/108.b66c9a8f.js"><link rel="prefetch" href="/assets/js/109.57f04174.js"><link rel="prefetch" href="/assets/js/11.242ea813.js"><link rel="prefetch" href="/assets/js/110.29e2499d.js"><link rel="prefetch" href="/assets/js/111.b721374e.js"><link rel="prefetch" href="/assets/js/112.44732d74.js"><link rel="prefetch" href="/assets/js/113.18a4c509.js"><link rel="prefetch" href="/assets/js/114.0d8f2607.js"><link rel="prefetch" href="/assets/js/115.fbfba1eb.js"><link rel="prefetch" href="/assets/js/116.b394d6f1.js"><link rel="prefetch" href="/assets/js/117.31310d35.js"><link rel="prefetch" href="/assets/js/118.9449e49f.js"><link rel="prefetch" href="/assets/js/119.07c43a65.js"><link rel="prefetch" href="/assets/js/12.27121867.js"><link rel="prefetch" href="/assets/js/120.bfa7845b.js"><link rel="prefetch" href="/assets/js/121.bc24c094.js"><link rel="prefetch" href="/assets/js/122.33f80e4f.js"><link rel="prefetch" href="/assets/js/123.41140603.js"><link rel="prefetch" href="/assets/js/124.e5fcecb4.js"><link rel="prefetch" href="/assets/js/125.5d156960.js"><link rel="prefetch" href="/assets/js/126.21af8edc.js"><link rel="prefetch" href="/assets/js/127.94f1a74a.js"><link rel="prefetch" href="/assets/js/128.1443fd28.js"><link rel="prefetch" href="/assets/js/129.9c9730d2.js"><link rel="prefetch" href="/assets/js/13.3883cb5c.js"><link rel="prefetch" href="/assets/js/130.3ebaf1e9.js"><link rel="prefetch" href="/assets/js/131.2d9c5787.js"><link rel="prefetch" href="/assets/js/132.f9dd7e91.js"><link rel="prefetch" href="/assets/js/133.ad89487a.js"><link rel="prefetch" href="/assets/js/134.d1975511.js"><link rel="prefetch" href="/assets/js/135.5023bae6.js"><link rel="prefetch" href="/assets/js/136.a836f92f.js"><link rel="prefetch" href="/assets/js/137.031b1c91.js"><link rel="prefetch" href="/assets/js/138.808bb4c5.js"><link rel="prefetch" href="/assets/js/139.9eb29936.js"><link rel="prefetch" href="/assets/js/14.66eebc6d.js"><link rel="prefetch" href="/assets/js/140.790e788a.js"><link rel="prefetch" href="/assets/js/141.861cd277.js"><link rel="prefetch" href="/assets/js/142.80570522.js"><link rel="prefetch" href="/assets/js/143.9299561a.js"><link rel="prefetch" href="/assets/js/144.880c0628.js"><link rel="prefetch" href="/assets/js/145.0d4332a7.js"><link rel="prefetch" href="/assets/js/146.e48d5d3f.js"><link rel="prefetch" href="/assets/js/147.969b5194.js"><link rel="prefetch" href="/assets/js/148.a56545f4.js"><link rel="prefetch" href="/assets/js/149.b6a0c0c4.js"><link rel="prefetch" href="/assets/js/15.0953eb10.js"><link rel="prefetch" href="/assets/js/150.0782606d.js"><link rel="prefetch" href="/assets/js/151.5683c2c2.js"><link rel="prefetch" href="/assets/js/152.b9e6108f.js"><link rel="prefetch" href="/assets/js/153.5f4e036b.js"><link rel="prefetch" href="/assets/js/154.1586319b.js"><link rel="prefetch" href="/assets/js/155.d5148213.js"><link rel="prefetch" href="/assets/js/156.0bf09079.js"><link rel="prefetch" href="/assets/js/157.de989c5f.js"><link rel="prefetch" href="/assets/js/158.2d4ad862.js"><link rel="prefetch" href="/assets/js/159.969149d7.js"><link rel="prefetch" href="/assets/js/16.be3a02b8.js"><link rel="prefetch" href="/assets/js/160.78670d5a.js"><link rel="prefetch" href="/assets/js/161.1cd134b5.js"><link rel="prefetch" href="/assets/js/162.ff855c9e.js"><link rel="prefetch" href="/assets/js/163.be160611.js"><link rel="prefetch" href="/assets/js/164.05d19e54.js"><link rel="prefetch" href="/assets/js/165.a50ca901.js"><link rel="prefetch" href="/assets/js/166.7e46ca06.js"><link rel="prefetch" href="/assets/js/167.f3bc9b1a.js"><link rel="prefetch" href="/assets/js/168.5dbef9ef.js"><link rel="prefetch" href="/assets/js/169.62ebff32.js"><link rel="prefetch" href="/assets/js/17.9b09b22d.js"><link rel="prefetch" href="/assets/js/170.d07644e9.js"><link rel="prefetch" href="/assets/js/171.c66629ae.js"><link rel="prefetch" href="/assets/js/172.198937cc.js"><link rel="prefetch" href="/assets/js/173.6f1d25bb.js"><link rel="prefetch" href="/assets/js/174.4301124f.js"><link rel="prefetch" href="/assets/js/175.52d930f3.js"><link rel="prefetch" href="/assets/js/176.0a709f70.js"><link rel="prefetch" href="/assets/js/177.677a710c.js"><link rel="prefetch" href="/assets/js/178.ca5b82c4.js"><link rel="prefetch" href="/assets/js/179.3bf817aa.js"><link rel="prefetch" href="/assets/js/18.122d5826.js"><link rel="prefetch" href="/assets/js/180.d6609806.js"><link rel="prefetch" href="/assets/js/181.f1fddd4e.js"><link rel="prefetch" href="/assets/js/182.b157bcef.js"><link rel="prefetch" href="/assets/js/183.fc45ef1f.js"><link rel="prefetch" href="/assets/js/184.27c76bd8.js"><link rel="prefetch" href="/assets/js/185.60e0c4f0.js"><link rel="prefetch" href="/assets/js/186.5e5cc224.js"><link rel="prefetch" href="/assets/js/187.8b1b0fef.js"><link rel="prefetch" href="/assets/js/188.b1c25ca7.js"><link rel="prefetch" href="/assets/js/189.a1554dd6.js"><link rel="prefetch" href="/assets/js/19.9b7b8a2e.js"><link rel="prefetch" href="/assets/js/190.d570a033.js"><link rel="prefetch" href="/assets/js/191.65b131c8.js"><link rel="prefetch" href="/assets/js/192.b8e6cbed.js"><link rel="prefetch" href="/assets/js/193.5b4a249f.js"><link rel="prefetch" href="/assets/js/194.0b990bce.js"><link rel="prefetch" href="/assets/js/195.36a17d0f.js"><link rel="prefetch" href="/assets/js/196.7f934e27.js"><link rel="prefetch" href="/assets/js/197.d79fb1cc.js"><link rel="prefetch" href="/assets/js/198.4f793066.js"><link rel="prefetch" href="/assets/js/199.c3a9c262.js"><link rel="prefetch" href="/assets/js/20.cf088c3b.js"><link rel="prefetch" href="/assets/js/200.9b3f4e62.js"><link rel="prefetch" href="/assets/js/201.69d0d24c.js"><link rel="prefetch" href="/assets/js/202.c9d492d5.js"><link rel="prefetch" href="/assets/js/203.b5809cc8.js"><link rel="prefetch" href="/assets/js/204.f75323db.js"><link rel="prefetch" href="/assets/js/205.43f0a3f2.js"><link rel="prefetch" href="/assets/js/206.ec3a5703.js"><link rel="prefetch" href="/assets/js/207.6a13e9ee.js"><link rel="prefetch" href="/assets/js/208.bcb17d87.js"><link rel="prefetch" href="/assets/js/209.451e2e0a.js"><link rel="prefetch" href="/assets/js/21.74ba2b3e.js"><link rel="prefetch" href="/assets/js/210.270f1973.js"><link rel="prefetch" href="/assets/js/211.e0f5c71f.js"><link rel="prefetch" href="/assets/js/212.3b65856b.js"><link rel="prefetch" href="/assets/js/213.593f93f2.js"><link rel="prefetch" href="/assets/js/214.30eaa159.js"><link rel="prefetch" href="/assets/js/215.55b67e29.js"><link rel="prefetch" href="/assets/js/216.a084f9ef.js"><link rel="prefetch" href="/assets/js/217.bd6d9c4a.js"><link rel="prefetch" href="/assets/js/218.afb01d10.js"><link rel="prefetch" href="/assets/js/219.50a9778c.js"><link rel="prefetch" href="/assets/js/22.f9d73f8a.js"><link rel="prefetch" href="/assets/js/220.6ecbd946.js"><link rel="prefetch" href="/assets/js/221.2f844304.js"><link rel="prefetch" href="/assets/js/222.a9c9ecd1.js"><link rel="prefetch" href="/assets/js/223.517813e9.js"><link rel="prefetch" href="/assets/js/224.cf6ca794.js"><link rel="prefetch" href="/assets/js/225.f88e7104.js"><link rel="prefetch" href="/assets/js/226.0135c33a.js"><link rel="prefetch" href="/assets/js/227.0aded7a3.js"><link rel="prefetch" href="/assets/js/228.ac120f0d.js"><link rel="prefetch" href="/assets/js/229.d5c30f16.js"><link rel="prefetch" href="/assets/js/23.91ba0b88.js"><link rel="prefetch" href="/assets/js/230.d14a3b0e.js"><link rel="prefetch" href="/assets/js/231.b0216fac.js"><link rel="prefetch" href="/assets/js/232.4f6b6373.js"><link rel="prefetch" href="/assets/js/233.0f3d666a.js"><link rel="prefetch" href="/assets/js/234.fb6110df.js"><link rel="prefetch" href="/assets/js/235.bb1d80a7.js"><link rel="prefetch" href="/assets/js/236.7e36d034.js"><link rel="prefetch" href="/assets/js/237.c026991c.js"><link rel="prefetch" href="/assets/js/238.01a1d668.js"><link rel="prefetch" href="/assets/js/239.3fb83483.js"><link rel="prefetch" href="/assets/js/24.de37758e.js"><link rel="prefetch" href="/assets/js/240.b09d943f.js"><link rel="prefetch" href="/assets/js/241.abcc8b65.js"><link rel="prefetch" href="/assets/js/242.67867070.js"><link rel="prefetch" href="/assets/js/243.18ef3398.js"><link rel="prefetch" href="/assets/js/244.afe8e0b9.js"><link rel="prefetch" href="/assets/js/245.53053187.js"><link rel="prefetch" href="/assets/js/246.20d4e857.js"><link rel="prefetch" href="/assets/js/247.78cf01d5.js"><link rel="prefetch" href="/assets/js/248.d7083c9e.js"><link rel="prefetch" href="/assets/js/249.f3fbd856.js"><link rel="prefetch" href="/assets/js/25.77e4633a.js"><link rel="prefetch" href="/assets/js/250.8db63391.js"><link rel="prefetch" href="/assets/js/251.2099ebdb.js"><link rel="prefetch" href="/assets/js/252.811a7e8c.js"><link rel="prefetch" href="/assets/js/253.c5296748.js"><link rel="prefetch" href="/assets/js/254.03023b0c.js"><link rel="prefetch" href="/assets/js/255.e5bf4735.js"><link rel="prefetch" href="/assets/js/256.485d661c.js"><link rel="prefetch" href="/assets/js/257.70333061.js"><link rel="prefetch" href="/assets/js/258.cb83463b.js"><link rel="prefetch" href="/assets/js/259.a02febe0.js"><link rel="prefetch" href="/assets/js/26.0057d37b.js"><link rel="prefetch" href="/assets/js/260.d0cdc5bb.js"><link rel="prefetch" href="/assets/js/261.3c8b8c14.js"><link rel="prefetch" href="/assets/js/262.ea831304.js"><link rel="prefetch" href="/assets/js/263.8af36533.js"><link rel="prefetch" href="/assets/js/264.cb79ef91.js"><link rel="prefetch" href="/assets/js/265.9a2f2a85.js"><link rel="prefetch" href="/assets/js/266.ca225af9.js"><link rel="prefetch" href="/assets/js/267.c1696137.js"><link rel="prefetch" href="/assets/js/268.260a8ab7.js"><link rel="prefetch" href="/assets/js/269.33629f13.js"><link rel="prefetch" href="/assets/js/27.9e25f953.js"><link rel="prefetch" href="/assets/js/270.e5fa0340.js"><link rel="prefetch" href="/assets/js/271.8f9420fc.js"><link rel="prefetch" href="/assets/js/272.c03fdadb.js"><link rel="prefetch" href="/assets/js/273.df3db881.js"><link rel="prefetch" href="/assets/js/274.4f59983e.js"><link rel="prefetch" href="/assets/js/275.785fd825.js"><link rel="prefetch" href="/assets/js/276.4658b553.js"><link rel="prefetch" href="/assets/js/277.234e8c60.js"><link rel="prefetch" href="/assets/js/278.8b7117be.js"><link rel="prefetch" href="/assets/js/279.2caa2bbe.js"><link rel="prefetch" href="/assets/js/28.0a801078.js"><link rel="prefetch" href="/assets/js/280.70f3e9dc.js"><link rel="prefetch" href="/assets/js/281.7d815a5c.js"><link rel="prefetch" href="/assets/js/282.9e1cd96b.js"><link rel="prefetch" href="/assets/js/283.5704a51c.js"><link rel="prefetch" href="/assets/js/284.ac2bf191.js"><link rel="prefetch" href="/assets/js/285.6e89e254.js"><link rel="prefetch" href="/assets/js/286.c89d7656.js"><link rel="prefetch" href="/assets/js/287.7446e94d.js"><link rel="prefetch" href="/assets/js/288.479655dd.js"><link rel="prefetch" href="/assets/js/289.659caaed.js"><link rel="prefetch" href="/assets/js/29.015a0cef.js"><link rel="prefetch" href="/assets/js/290.0493ffb9.js"><link rel="prefetch" href="/assets/js/291.81e22a75.js"><link rel="prefetch" href="/assets/js/293.183d5889.js"><link rel="prefetch" href="/assets/js/294.49874dd4.js"><link rel="prefetch" href="/assets/js/295.d45ea8c1.js"><link rel="prefetch" href="/assets/js/296.d386f7e9.js"><link rel="prefetch" href="/assets/js/297.2697f10a.js"><link rel="prefetch" href="/assets/js/298.0790ad48.js"><link rel="prefetch" href="/assets/js/299.732aafc4.js"><link rel="prefetch" href="/assets/js/30.03cf4852.js"><link rel="prefetch" href="/assets/js/300.8147e316.js"><link rel="prefetch" href="/assets/js/301.7986fcfa.js"><link rel="prefetch" href="/assets/js/302.fbea453a.js"><link rel="prefetch" href="/assets/js/303.90b0c08b.js"><link rel="prefetch" href="/assets/js/304.ae9e278b.js"><link rel="prefetch" href="/assets/js/305.3a44047c.js"><link rel="prefetch" href="/assets/js/306.d1ed6747.js"><link rel="prefetch" href="/assets/js/307.19b6834f.js"><link rel="prefetch" href="/assets/js/308.75fc5433.js"><link rel="prefetch" href="/assets/js/309.912d7531.js"><link rel="prefetch" href="/assets/js/31.9af92350.js"><link rel="prefetch" href="/assets/js/310.2bb387a8.js"><link rel="prefetch" href="/assets/js/311.da17b546.js"><link rel="prefetch" href="/assets/js/312.033eed97.js"><link rel="prefetch" href="/assets/js/313.fc0e389d.js"><link rel="prefetch" href="/assets/js/314.7f57565d.js"><link rel="prefetch" href="/assets/js/315.a707c807.js"><link rel="prefetch" href="/assets/js/316.920bb2f9.js"><link rel="prefetch" href="/assets/js/317.0719853c.js"><link rel="prefetch" href="/assets/js/318.41dcab2e.js"><link rel="prefetch" href="/assets/js/319.3734e844.js"><link rel="prefetch" href="/assets/js/32.e5e702b0.js"><link rel="prefetch" href="/assets/js/320.0bdbffa7.js"><link rel="prefetch" href="/assets/js/321.a9656a07.js"><link rel="prefetch" href="/assets/js/322.5e9450f4.js"><link rel="prefetch" href="/assets/js/323.674bf9b3.js"><link rel="prefetch" href="/assets/js/324.aa72ae49.js"><link rel="prefetch" href="/assets/js/325.f77fd1b4.js"><link rel="prefetch" href="/assets/js/326.4ecf6add.js"><link rel="prefetch" href="/assets/js/327.09a29a3d.js"><link rel="prefetch" href="/assets/js/328.40c1d259.js"><link rel="prefetch" href="/assets/js/329.e776998e.js"><link rel="prefetch" href="/assets/js/33.d0eafbb9.js"><link rel="prefetch" href="/assets/js/330.84027fd8.js"><link rel="prefetch" href="/assets/js/331.f068bd55.js"><link rel="prefetch" href="/assets/js/332.0e5f0f38.js"><link rel="prefetch" href="/assets/js/333.1c7124ce.js"><link rel="prefetch" href="/assets/js/334.813ded8e.js"><link rel="prefetch" href="/assets/js/335.8bed5efb.js"><link rel="prefetch" href="/assets/js/336.fc89e644.js"><link rel="prefetch" href="/assets/js/337.91b7a655.js"><link rel="prefetch" href="/assets/js/338.cfff9d17.js"><link rel="prefetch" href="/assets/js/339.17770dae.js"><link rel="prefetch" href="/assets/js/34.85849ed4.js"><link rel="prefetch" href="/assets/js/340.5e3f5af3.js"><link rel="prefetch" href="/assets/js/341.eef6be19.js"><link rel="prefetch" href="/assets/js/342.d5050fa2.js"><link rel="prefetch" href="/assets/js/343.b5963f08.js"><link rel="prefetch" href="/assets/js/344.b246b989.js"><link rel="prefetch" href="/assets/js/345.cb808b6a.js"><link rel="prefetch" href="/assets/js/346.d1af1e00.js"><link rel="prefetch" href="/assets/js/347.bcf05eb4.js"><link rel="prefetch" href="/assets/js/348.ec1dc1ed.js"><link rel="prefetch" href="/assets/js/349.cd1e39fa.js"><link rel="prefetch" href="/assets/js/35.5612ab6a.js"><link rel="prefetch" href="/assets/js/350.9f16f781.js"><link rel="prefetch" href="/assets/js/351.b563631f.js"><link rel="prefetch" href="/assets/js/352.007f942f.js"><link rel="prefetch" href="/assets/js/353.bbf4e9c2.js"><link rel="prefetch" href="/assets/js/354.4311bd66.js"><link rel="prefetch" href="/assets/js/355.108499f2.js"><link rel="prefetch" href="/assets/js/356.a81636e7.js"><link rel="prefetch" href="/assets/js/357.35ca1b7b.js"><link rel="prefetch" href="/assets/js/358.e7025787.js"><link rel="prefetch" href="/assets/js/359.91cac463.js"><link rel="prefetch" href="/assets/js/36.5a401e9f.js"><link rel="prefetch" href="/assets/js/360.f65ac7e5.js"><link rel="prefetch" href="/assets/js/361.58929dff.js"><link rel="prefetch" href="/assets/js/362.d65c727e.js"><link rel="prefetch" href="/assets/js/363.3b5d8085.js"><link rel="prefetch" href="/assets/js/364.d17737d3.js"><link rel="prefetch" href="/assets/js/365.e679ba47.js"><link rel="prefetch" href="/assets/js/366.5ceace94.js"><link rel="prefetch" href="/assets/js/367.140df2b7.js"><link rel="prefetch" href="/assets/js/368.e46272ab.js"><link rel="prefetch" href="/assets/js/369.39547fbd.js"><link rel="prefetch" href="/assets/js/37.15871763.js"><link rel="prefetch" href="/assets/js/370.ca1215ed.js"><link rel="prefetch" href="/assets/js/371.e25a2848.js"><link rel="prefetch" href="/assets/js/372.205e1d0f.js"><link rel="prefetch" href="/assets/js/373.8ba7c5ac.js"><link rel="prefetch" href="/assets/js/374.bf50b733.js"><link rel="prefetch" href="/assets/js/375.1c735a6d.js"><link rel="prefetch" href="/assets/js/376.9a087a53.js"><link rel="prefetch" href="/assets/js/377.edec1505.js"><link rel="prefetch" href="/assets/js/378.bfde20e4.js"><link rel="prefetch" href="/assets/js/379.f33acc18.js"><link rel="prefetch" href="/assets/js/38.b02b6af6.js"><link rel="prefetch" href="/assets/js/380.9fe6b811.js"><link rel="prefetch" href="/assets/js/381.286eb8c1.js"><link rel="prefetch" href="/assets/js/382.69e55228.js"><link rel="prefetch" href="/assets/js/383.d8aef30b.js"><link rel="prefetch" href="/assets/js/384.85cd434d.js"><link rel="prefetch" href="/assets/js/385.1477251c.js"><link rel="prefetch" href="/assets/js/386.b037901f.js"><link rel="prefetch" href="/assets/js/387.3b662ff8.js"><link rel="prefetch" href="/assets/js/388.9a6dd37c.js"><link rel="prefetch" href="/assets/js/389.61634031.js"><link rel="prefetch" href="/assets/js/39.b5f4c79a.js"><link rel="prefetch" href="/assets/js/390.9319e40d.js"><link rel="prefetch" href="/assets/js/391.e2cc7ea6.js"><link rel="prefetch" href="/assets/js/392.10795946.js"><link rel="prefetch" href="/assets/js/393.c4574540.js"><link rel="prefetch" href="/assets/js/394.e1e83e03.js"><link rel="prefetch" href="/assets/js/395.c7e1eb57.js"><link rel="prefetch" href="/assets/js/396.1ea42313.js"><link rel="prefetch" href="/assets/js/397.e8061a94.js"><link rel="prefetch" href="/assets/js/398.ecadeab8.js"><link rel="prefetch" href="/assets/js/399.dea55ac6.js"><link rel="prefetch" href="/assets/js/4.a195f7b6.js"><link rel="prefetch" href="/assets/js/40.f82f0187.js"><link rel="prefetch" href="/assets/js/400.6717ff58.js"><link rel="prefetch" href="/assets/js/401.d4ea37f7.js"><link rel="prefetch" href="/assets/js/402.41fdc4b2.js"><link rel="prefetch" href="/assets/js/403.41057259.js"><link rel="prefetch" href="/assets/js/404.837b6b86.js"><link rel="prefetch" href="/assets/js/405.49c9c7c2.js"><link rel="prefetch" href="/assets/js/406.edc5636f.js"><link rel="prefetch" href="/assets/js/407.b35a76d2.js"><link rel="prefetch" href="/assets/js/408.ab25fe0c.js"><link rel="prefetch" href="/assets/js/409.af049984.js"><link rel="prefetch" href="/assets/js/41.54dfae4f.js"><link rel="prefetch" href="/assets/js/410.9303989e.js"><link rel="prefetch" href="/assets/js/411.dfe89d6e.js"><link rel="prefetch" href="/assets/js/412.489496d1.js"><link rel="prefetch" href="/assets/js/413.a678292f.js"><link rel="prefetch" href="/assets/js/414.42ff683c.js"><link rel="prefetch" href="/assets/js/415.fa70f3c6.js"><link rel="prefetch" href="/assets/js/416.c2b52841.js"><link rel="prefetch" href="/assets/js/417.59336c03.js"><link rel="prefetch" href="/assets/js/418.877f3b66.js"><link rel="prefetch" href="/assets/js/419.f37696a2.js"><link rel="prefetch" href="/assets/js/42.e6b0aae2.js"><link rel="prefetch" href="/assets/js/420.ba59678e.js"><link rel="prefetch" href="/assets/js/421.b0459232.js"><link rel="prefetch" href="/assets/js/422.82169579.js"><link rel="prefetch" href="/assets/js/423.5c1482d0.js"><link rel="prefetch" href="/assets/js/424.49711d9b.js"><link rel="prefetch" href="/assets/js/425.8c514fcb.js"><link rel="prefetch" href="/assets/js/426.72898cfc.js"><link rel="prefetch" href="/assets/js/427.66eb3fe5.js"><link rel="prefetch" href="/assets/js/428.a7bd466b.js"><link rel="prefetch" href="/assets/js/429.8fd5e3a8.js"><link rel="prefetch" href="/assets/js/43.3fff5a4c.js"><link rel="prefetch" href="/assets/js/430.eebb256a.js"><link rel="prefetch" href="/assets/js/431.58e8895f.js"><link rel="prefetch" href="/assets/js/432.3f20b681.js"><link rel="prefetch" href="/assets/js/433.44e82676.js"><link rel="prefetch" href="/assets/js/434.03aec36f.js"><link rel="prefetch" href="/assets/js/435.2830cd69.js"><link rel="prefetch" href="/assets/js/436.f2fd5b33.js"><link rel="prefetch" href="/assets/js/437.c4e29f95.js"><link rel="prefetch" href="/assets/js/438.2e47506b.js"><link rel="prefetch" href="/assets/js/439.04fc1a57.js"><link rel="prefetch" href="/assets/js/44.b334ed25.js"><link rel="prefetch" href="/assets/js/440.60166986.js"><link rel="prefetch" href="/assets/js/441.2e885d78.js"><link rel="prefetch" href="/assets/js/442.9d0ff896.js"><link rel="prefetch" href="/assets/js/443.e902f3b9.js"><link rel="prefetch" href="/assets/js/444.4f0d0db9.js"><link rel="prefetch" href="/assets/js/445.372dde37.js"><link rel="prefetch" href="/assets/js/446.c5500da6.js"><link rel="prefetch" href="/assets/js/447.6af1425e.js"><link rel="prefetch" href="/assets/js/448.e0a893f1.js"><link rel="prefetch" href="/assets/js/449.87a7d812.js"><link rel="prefetch" href="/assets/js/45.244b7680.js"><link rel="prefetch" href="/assets/js/450.3eca4d3a.js"><link rel="prefetch" href="/assets/js/451.cfb7d1c7.js"><link rel="prefetch" href="/assets/js/452.2b0b0c4d.js"><link rel="prefetch" href="/assets/js/453.a500efaa.js"><link rel="prefetch" href="/assets/js/454.4a4b5dcd.js"><link rel="prefetch" href="/assets/js/455.d267e970.js"><link rel="prefetch" href="/assets/js/456.159a5914.js"><link rel="prefetch" href="/assets/js/457.02916722.js"><link rel="prefetch" href="/assets/js/458.693c4b3f.js"><link rel="prefetch" href="/assets/js/459.f84cf410.js"><link rel="prefetch" href="/assets/js/46.508f7d41.js"><link rel="prefetch" href="/assets/js/460.4f109a5b.js"><link rel="prefetch" href="/assets/js/461.37187de1.js"><link rel="prefetch" href="/assets/js/462.4992918e.js"><link rel="prefetch" href="/assets/js/463.871e7e95.js"><link rel="prefetch" href="/assets/js/464.5aa364f7.js"><link rel="prefetch" href="/assets/js/465.07d0b35d.js"><link rel="prefetch" href="/assets/js/466.24947b1a.js"><link rel="prefetch" href="/assets/js/467.47ef006b.js"><link rel="prefetch" href="/assets/js/468.cee17164.js"><link rel="prefetch" href="/assets/js/469.fdad5e4c.js"><link rel="prefetch" href="/assets/js/47.e56ee397.js"><link rel="prefetch" href="/assets/js/470.b3ff2f13.js"><link rel="prefetch" href="/assets/js/471.d496e211.js"><link rel="prefetch" href="/assets/js/472.2063a068.js"><link rel="prefetch" href="/assets/js/473.aa6bd5ba.js"><link rel="prefetch" href="/assets/js/474.7978914b.js"><link rel="prefetch" href="/assets/js/475.4bbf0340.js"><link rel="prefetch" href="/assets/js/476.eb332b52.js"><link rel="prefetch" href="/assets/js/477.53ea6252.js"><link rel="prefetch" href="/assets/js/478.edbe4a47.js"><link rel="prefetch" href="/assets/js/479.5fb38387.js"><link rel="prefetch" href="/assets/js/48.bec9faeb.js"><link rel="prefetch" href="/assets/js/480.f21ff9e0.js"><link rel="prefetch" href="/assets/js/481.8e611064.js"><link rel="prefetch" href="/assets/js/482.6deda435.js"><link rel="prefetch" href="/assets/js/483.cfba6764.js"><link rel="prefetch" href="/assets/js/484.5f4e17f6.js"><link rel="prefetch" href="/assets/js/485.0cd6f0c8.js"><link rel="prefetch" href="/assets/js/486.7a12b540.js"><link rel="prefetch" href="/assets/js/487.4f121773.js"><link rel="prefetch" href="/assets/js/488.212fc60c.js"><link rel="prefetch" href="/assets/js/489.511c7934.js"><link rel="prefetch" href="/assets/js/49.f271ac34.js"><link rel="prefetch" href="/assets/js/490.40543b1e.js"><link rel="prefetch" href="/assets/js/491.b9e02614.js"><link rel="prefetch" href="/assets/js/492.7020aa9c.js"><link rel="prefetch" href="/assets/js/493.5bc91ef5.js"><link rel="prefetch" href="/assets/js/494.3893fb8a.js"><link rel="prefetch" href="/assets/js/495.3e35ddd8.js"><link rel="prefetch" href="/assets/js/496.50fe0e61.js"><link rel="prefetch" href="/assets/js/497.945b4bd3.js"><link rel="prefetch" href="/assets/js/498.90de0ef4.js"><link rel="prefetch" href="/assets/js/499.8e450b6e.js"><link rel="prefetch" href="/assets/js/5.2a4451ec.js"><link rel="prefetch" href="/assets/js/50.e60dabfc.js"><link rel="prefetch" href="/assets/js/500.aad8b0da.js"><link rel="prefetch" href="/assets/js/501.e576988e.js"><link rel="prefetch" href="/assets/js/502.9542d6db.js"><link rel="prefetch" href="/assets/js/503.a19eff50.js"><link rel="prefetch" href="/assets/js/504.202eb2e4.js"><link rel="prefetch" href="/assets/js/505.373f7fd0.js"><link rel="prefetch" href="/assets/js/506.8bb184a6.js"><link rel="prefetch" href="/assets/js/507.a94e3f42.js"><link rel="prefetch" href="/assets/js/508.d867192b.js"><link rel="prefetch" href="/assets/js/509.5e515932.js"><link rel="prefetch" href="/assets/js/51.65940de1.js"><link rel="prefetch" href="/assets/js/510.584925b9.js"><link rel="prefetch" href="/assets/js/511.9c23909a.js"><link rel="prefetch" href="/assets/js/512.4a1b0e80.js"><link rel="prefetch" href="/assets/js/513.eadca66a.js"><link rel="prefetch" href="/assets/js/514.b9045771.js"><link rel="prefetch" href="/assets/js/515.79043a80.js"><link rel="prefetch" href="/assets/js/516.f7834f37.js"><link rel="prefetch" href="/assets/js/517.cc500f62.js"><link rel="prefetch" href="/assets/js/518.b192a4a5.js"><link rel="prefetch" href="/assets/js/519.a3b03f32.js"><link rel="prefetch" href="/assets/js/52.d8e20165.js"><link rel="prefetch" href="/assets/js/520.8da09b22.js"><link rel="prefetch" href="/assets/js/521.93a8a062.js"><link rel="prefetch" href="/assets/js/522.c76d898b.js"><link rel="prefetch" href="/assets/js/523.8aed06fe.js"><link rel="prefetch" href="/assets/js/524.abd65c1f.js"><link rel="prefetch" href="/assets/js/525.3bd43a2b.js"><link rel="prefetch" href="/assets/js/526.35a12d3d.js"><link rel="prefetch" href="/assets/js/527.d1f03b8e.js"><link rel="prefetch" href="/assets/js/528.68b286e8.js"><link rel="prefetch" href="/assets/js/53.bf825409.js"><link rel="prefetch" href="/assets/js/54.2bd5a2fe.js"><link rel="prefetch" href="/assets/js/55.9d4b8667.js"><link rel="prefetch" href="/assets/js/56.aa94202c.js"><link rel="prefetch" href="/assets/js/57.031c737d.js"><link rel="prefetch" href="/assets/js/58.89130d49.js"><link rel="prefetch" href="/assets/js/59.96b86b80.js"><link rel="prefetch" href="/assets/js/6.3450075a.js"><link rel="prefetch" href="/assets/js/60.53b7d88b.js"><link rel="prefetch" href="/assets/js/61.0c0f12f7.js"><link rel="prefetch" href="/assets/js/62.2dc7dc16.js"><link rel="prefetch" href="/assets/js/63.3a66528e.js"><link rel="prefetch" href="/assets/js/64.ca5c6060.js"><link rel="prefetch" href="/assets/js/65.5832f0ec.js"><link rel="prefetch" href="/assets/js/66.d486a91a.js"><link rel="prefetch" href="/assets/js/67.2a47c8f6.js"><link rel="prefetch" href="/assets/js/68.38ac76fc.js"><link rel="prefetch" href="/assets/js/69.7f8c7118.js"><link rel="prefetch" href="/assets/js/7.c5c54fb4.js"><link rel="prefetch" href="/assets/js/70.368e2128.js"><link rel="prefetch" href="/assets/js/71.79ab0b38.js"><link rel="prefetch" href="/assets/js/72.b43649cf.js"><link rel="prefetch" href="/assets/js/73.0478a06c.js"><link rel="prefetch" href="/assets/js/74.d200c141.js"><link rel="prefetch" href="/assets/js/75.2c99b650.js"><link rel="prefetch" href="/assets/js/76.316509fa.js"><link rel="prefetch" href="/assets/js/77.e6edd439.js"><link rel="prefetch" href="/assets/js/78.4dc668e5.js"><link rel="prefetch" href="/assets/js/79.036924ec.js"><link rel="prefetch" href="/assets/js/8.de5c69e7.js"><link rel="prefetch" href="/assets/js/80.293948a6.js"><link rel="prefetch" href="/assets/js/81.fcfc5c23.js"><link rel="prefetch" href="/assets/js/82.362d02a9.js"><link rel="prefetch" href="/assets/js/83.c4dbb547.js"><link rel="prefetch" href="/assets/js/84.f08949cb.js"><link rel="prefetch" href="/assets/js/85.f2e4448e.js"><link rel="prefetch" href="/assets/js/86.fbd4f3d9.js"><link rel="prefetch" href="/assets/js/87.afc9310c.js"><link rel="prefetch" href="/assets/js/88.d7486a20.js"><link rel="prefetch" href="/assets/js/89.f0d0304a.js"><link rel="prefetch" href="/assets/js/9.18fb6454.js"><link rel="prefetch" href="/assets/js/90.b9f22784.js"><link rel="prefetch" href="/assets/js/91.6878b587.js"><link rel="prefetch" href="/assets/js/92.295618c2.js"><link rel="prefetch" href="/assets/js/93.ae3dfa9b.js"><link rel="prefetch" href="/assets/js/94.cf487101.js"><link rel="prefetch" href="/assets/js/95.427e00a4.js"><link rel="prefetch" href="/assets/js/96.2a84236c.js"><link rel="prefetch" href="/assets/js/97.6767cf86.js"><link rel="prefetch" href="/assets/js/98.77656225.js"><link rel="prefetch" href="/assets/js/99.902cfc13.js"><link rel="prefetch" href="/assets/js/vendors~docsearch.eff714eb.js"> |
| <link rel="stylesheet" href="/assets/css/0.styles.ccadf850.css"> |
| </head> |
| <body> |
| <div id="app" data-server-rendered="true"><div class="theme-container"><header class="navbar"><div class="sidebar-button"><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" role="img" viewBox="0 0 448 512" class="icon"><path fill="currentColor" d="M436 124H12c-6.627 0-12-5.373-12-12V80c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12zm0 160H12c-6.627 0-12-5.373-12-12v-32c0-6.627 5.373-12 12-12h424c6.627 0 12 5.373 12 12v32c0 6.627-5.373 12-12 12z"></path></svg></div> <a href="/zh/" class="home-link router-link-active"><img src="/img/logo.png" alt=" " class="logo"></a> <div class="links"><div class="search-box"><input aria-label="Search" autocomplete="off" spellcheck="false" value=""> <!----></div> <nav class="nav-links can-hide"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">文档</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/Get Started/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/Get Started/QuickStart.html" class="nav-link">V0.11.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.10.x/Get Started/QuickStart.html" class="nav-link">V0.10.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.9.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.9.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.8.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.8.x</a></li></ul></div></div><div class="nav-item"><a href="/zh/SystemDesign/Architecture/Architecture.html" class="nav-link">系统设计</a></div><div class="nav-item"><a href="/zh/Download/" class="nav-link">下载</a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">社区</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://cwiki.apache.org/confluence/display/iotdb" class="nav-link external"> |
| Wiki |
| <!----></a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Project Committers.html" class="nav-link">开发人员</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Powered By.html" class="nav-link">技术支持</a></li><li class="dropdown-item"><!----> <a href="/Community/Materials.html" class="nav-link">活动与报告</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Feedback.html" class="nav-link">交流与反馈</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">开发</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/Development/VoteRelease.html" class="nav-link">如何投票</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/HowToCommit.html" class="nav-link">如何提交代码</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/Committer.html" class="nav-link">成为Committer</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/ContributeGuide.html" class="nav-link">项目开发指南</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/format-changelist.html" class="nav-link">TsFile的更改列表</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/rpc-changelist.html" class="nav-link">RPC变更清单</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">ASF</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="http://www.apache.org/" class="nav-link external"> |
| 基金会 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/licenses/" class="nav-link external"> |
| 许可证 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/security/" class="nav-link external"> |
| 安全 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/sponsorship.html" class="nav-link external"> |
| 赞助 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/thanks.html" class="nav-link external"> |
| 致谢 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/events/current-event" class="nav-link external"> |
| 活动 |
| <!----></a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">语言</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/SystemDesign/DataQuery/GroupByQuery.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/SystemDesign/DataQuery/GroupByQuery.html" aria-current="page" class="nav-link router-link-exact-active router-link-active">简体中文</a></li></ul></div></div> <a href="https://github.com/apache/iotdb.git" target="_blank" rel="noopener noreferrer" class="repo-link"> |
| gitHub |
| <span><svg 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" class="icon outbound"><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="sr-only">(opens new window)</span></span></a></nav></div></header> <div class="sidebar-mask"></div> <aside class="sidebar"><nav class="nav-links"><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">文档</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/UserGuide/Master/Get Started/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.11.x/Get Started/QuickStart.html" class="nav-link">V0.11.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.10.x/Get Started/QuickStart.html" class="nav-link">V0.10.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.9.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.9.x</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.8.x/0-Get Started/1-QuickStart.html" class="nav-link">V0.8.x</a></li></ul></div></div><div class="nav-item"><a href="/zh/SystemDesign/Architecture/Architecture.html" class="nav-link">系统设计</a></div><div class="nav-item"><a href="/zh/Download/" class="nav-link">下载</a></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">社区</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="https://cwiki.apache.org/confluence/display/iotdb" class="nav-link external"> |
| Wiki |
| <!----></a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Project Committers.html" class="nav-link">开发人员</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Community-Powered By.html" class="nav-link">技术支持</a></li><li class="dropdown-item"><!----> <a href="/Community/Materials.html" class="nav-link">活动与报告</a></li><li class="dropdown-item"><!----> <a href="/zh/Community/Feedback.html" class="nav-link">交流与反馈</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">开发</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/zh/Development/VoteRelease.html" class="nav-link">如何投票</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/HowToCommit.html" class="nav-link">如何提交代码</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/Committer.html" class="nav-link">成为Committer</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/ContributeGuide.html" class="nav-link">项目开发指南</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/format-changelist.html" class="nav-link">TsFile的更改列表</a></li><li class="dropdown-item"><!----> <a href="/zh/Development/rpc-changelist.html" class="nav-link">RPC变更清单</a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">ASF</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="http://www.apache.org/" class="nav-link external"> |
| 基金会 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/licenses/" class="nav-link external"> |
| 许可证 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/security/" class="nav-link external"> |
| 安全 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/sponsorship.html" class="nav-link external"> |
| 赞助 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/foundation/thanks.html" class="nav-link external"> |
| 致谢 |
| <!----></a></li><li class="dropdown-item"><!----> <a href="http://www.apache.org/events/current-event" class="nav-link external"> |
| 活动 |
| <!----></a></li></ul></div></div><div class="nav-item"><div class="dropdown-wrapper"><a class="dropdown-title"><span class="title">语言</span> <span class="arrow right"></span></a> <ul class="nav-dropdown" style="display:none;"><li class="dropdown-item"><!----> <a href="/SystemDesign/DataQuery/GroupByQuery.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/SystemDesign/DataQuery/GroupByQuery.html" aria-current="page" class="nav-link router-link-exact-active router-link-active">简体中文</a></li></ul></div></div> <a href="https://github.com/apache/iotdb.git" target="_blank" rel="noopener noreferrer" class="repo-link"> |
| gitHub |
| <span><svg 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" class="icon outbound"><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="sr-only">(opens new window)</span></span></a></nav> <ul class="sidebar-links"><li><section class="sidebar-group depth-0"><p class="sidebar-heading"><span>系统设计</span> <!----></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>应用概览</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>TsFile</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>查询引擎</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>元数据管理</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>存储引擎</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading open"><span>数据查询</span> <span class="arrow down"></span></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/zh/SystemDesign/DataQuery/DataQuery.html" class="sidebar-link">数据查询</a></li><li><a href="/zh/SystemDesign/DataQuery/QueryFundamentals.html" class="sidebar-link">查询基础介绍</a></li><li><a href="/zh/SystemDesign/DataQuery/SeriesReader.html" class="sidebar-link">查询基础组件</a></li><li><a href="/zh/SystemDesign/DataQuery/RawDataQuery.html" class="sidebar-link">原始数据查询</a></li><li><a href="/zh/SystemDesign/DataQuery/AggregationQuery.html" class="sidebar-link">聚合查询</a></li><li><a href="/zh/SystemDesign/DataQuery/GroupByQuery.html" aria-current="page" class="active sidebar-link">降采样查询</a></li><li><a href="/zh/SystemDesign/DataQuery/LastQuery.html" class="sidebar-link">最近时间戳 Last 查询</a></li><li><a href="/zh/SystemDesign/DataQuery/AlignByDeviceQuery.html" class="sidebar-link">按设备对齐查询</a></li><li><a href="/zh/SystemDesign/DataQuery/FillFunction.html" class="sidebar-link">空值填充</a></li><li><a href="/zh/SystemDesign/DataQuery/GroupByFillQuery.html" class="sidebar-link">降采样补空值查询</a></li><li><a href="/zh/SystemDesign/DataQuery/OrderByTimeQuery.html" class="sidebar-link">按时间倒序查询</a></li></ul></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>工具</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>连接器</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>客户端</span> <span class="arrow right"></span></p> <!----></section></li></ul> </aside> <main class="page"> <div class="content content__default"><h1 id="降采样查询"><a href="#降采样查询" class="header-anchor">#</a> 降采样查询</h1> <ul><li>org.apache.iotdb.db.query.dataset.groupby.GroupByEngineDataSet</li></ul> <p>降采样查询的结果集都会继承 <code>GroupByEngineDataSet</code>，该类包含如下字段：</p> <ul><li>protected long queryId</li> <li>private long interval</li> <li>private long slidingStep</li></ul> <p>以下两个字段针对整个查询，时间段为左闭右开，即 <code>[startTime, endTime)</code>：</p> <ul><li>private long startTime</li> <li>private long endTime</li></ul> <p>以下字段针对当前分段，时间段为左闭右开，即 <code>[curStartTime, curEndTime)</code></p> <ul><li>protected long curStartTime;</li> <li>protected long curEndTime;</li> <li>private int usedIndex;</li> <li>protected boolean hasCachedTimeInterval;</li></ul> <p><code>GroupByEngineDataSet</code> 的核心方法很容易，首先根据是否有缓存的时间段判断是否有下一分段，有则返回 <code>true</code>；如果没有就计算分段开始时间，将 <code>usedIndex</code> 增加1。如果分段开始时间已经超过了查询结束时间，返回 <code>false</code>，否则计算查询结束时间，将 <code>hasCachedTimeInterval</code> 置为<code>true</code>，并返回 <code>true</code>：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>protected boolean hasNextWithoutConstraint() { |
| if (hasCachedTimeInterval) { |
| return true; |
| } |
| |
| curStartTime = usedIndex * slidingStep + startTime; |
| usedIndex++; |
| if (curStartTime < endTime) { |
| hasCachedTimeInterval = true; |
| curEndTime = Math.min(curStartTime + interval, endTime); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><h2 id="不带值过滤条件的降采样查询"><a href="#不带值过滤条件的降采样查询" class="header-anchor">#</a> 不带值过滤条件的降采样查询</h2> <p>不带值过滤条件的降采样查询逻辑主要在 <code>GroupByWithoutValueFilterDataSet</code> 类中，该类继承了 <code>GroupByEngineDataSet</code>。</p> <p>该类有如下关键字段：</p> <ul><li><p>private Map<Path, GroupByExecutor> pathExecutors 针对于相同 <code>Path</code> 的聚合函数进行归类，并封装成 <code>GroupByExecutor</code> , |
| <code>GroupByExecutor</code> 封装了每个 <code>Path</code> 的数据计算逻辑和方法，在后面介绍</p></li> <li><p>private TimeRange timeRange 将每次计算的时间区间封装成对象，用于判断 <code>Statistics</code> 是否可以直接参与计算</p></li> <li><p>private Filter timeFilter 将用户定义的查询区间生成为 <code>Filter</code> 对象，用来过滤可用的<code>文件</code>、<code>chunk</code>、<code>page</code></p></li></ul> <p>首先，在初始化 <code>initGroupBy()</code> 方法中，根据表达式计算出 <code>timeFilter</code>，并为每个 <code>path</code> 生成 <code>GroupByExecutor</code> 。</p> <p><code>nextWithoutConstraint()</code> 方法通过调用 <code>GroupByExecutor.calcResult()</code> 方法计算出每个 <code>Path</code> 内的所有聚合方法的聚合值 <code>aggregateResults</code>。 |
| 以下方法用于将结果列表转化为 RowRecord，需要注意列表中没有结果时， RowRecord 中添加 <code>null</code>：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>for (AggregateResult res : fields) { |
| if (res == null) { |
| record.addField(null); |
| continue; |
| } |
| record.addField(res.getResult(), res.getResultDataType()); |
| } |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><h3 id="groupbyexecutor"><a href="#groupbyexecutor" class="header-anchor">#</a> GroupByExecutor</h3> <p>封装了相同 path 下的所有聚合函数的计算方法，该类有如下关键字段：</p> <ul><li>private IAggregateReader reader 读取当前 <code>Path</code> 数据用到的 <code>SeriesAggregateReader</code></li> <li>private BatchData preCachedData 每次从 <code>Reader</code> 读取的数据是一批，很有可能会超过当前的时间段，那么这个 <code>BatchData</code> 就会被缓存留给下一次使用</li> <li>private List<Pair<AggregateResult, Integer>> results 存储了当前 <code>Path</code> 里所有的聚合方法， |
| 例如：<code>select count(a),sum(a),avg(b)</code> ，<code>count</code> 和 <code>sum</code> 方法就被存到一起。 |
| 右侧的 <code>Integer</code> 用于结果集转化为RowRecord之前，需要将其顺序还原为用户查询的顺序。</li></ul> <h4 id="主要方法"><a href="#主要方法" class="header-anchor">#</a> 主要方法</h4> <div class="language- line-numbers-mode"><pre class="language-text"><code>//从 reader 中读取数据，并计算，该类的主方法。 |
| private List<Pair<AggregateResult, Integer>> calcResult() throws IOException, QueryProcessException; |
| |
| //添加当前 path 的聚合操作 |
| private void addAggregateResult(AggregateResult aggrResult, int index); |
| |
| //判断当前 path 是否已经完成了所有的聚合计算 |
| private boolean isEndCalc(); |
| |
| //从上次计算没有使用完缓存的 BatchData 中计算结果 |
| private boolean calcFromCacheData() throws IOException; |
| |
| //使用 BatchData 计算 |
| private void calcFromBatch(BatchData batchData) throws IOException; |
| |
| //使用 Page 或 Chunk 的 Statistics 信息直接计算结果 |
| private void calcFromStatistics(Statistics statistics) throws QueryProcessException; |
| |
| //清空所有计算结果 |
| private void resetAggregateResults(); |
| |
| //遍历并计算 page 中的数据 |
| private boolean readAndCalcFromPage() throws IOException, QueryProcessException; |
| |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br></div></div><p><code>GroupByExecutor</code> 中因为相同 <code>path</code> 的不同聚合函数使用的数据是相同的，所以在入口方法 <code>calcResult</code> 中负责读取该 <code>Path</code> 的所有数据, |
| 取出来的数据再调用 <code>calcFromBatch</code> 方法完成遍历所有聚合函数对 <code>BatchData</code> 的计算。</p> <p><code>calcResult</code> 方法返回当前 Path 下的所有AggregateResult，以及当前聚合值在用户查询顺序里的位置，其主要逻辑：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>//把上次遗留的数据先做计算，如果能直接获得结果就结束计算 |
| if (calcFromCacheData()) { |
| return results; |
| } |
| |
| //因为一个chunk是包含多个page的，那么必须先使用完当前chunk的page，再打开下一个chunk |
| if (readAndCalcFromPage()) { |
| return results; |
| } |
| |
| //遗留的数据如果计算完了就要打开新的chunk继续计算 |
| while (reader.hasNextChunk()) { |
| Statistics chunkStatistics = reader.currentChunkStatistics(); |
| // 判断能否使用 Statistics，并执行计算 |
| .... |
| // 跳过当前chunk |
| reader.skipCurrentChunk(); |
| // 如果已经获取到了所有结果就结束计算 |
| if (isEndCalc()) { |
| return true; |
| } |
| continue; |
| } |
| //如果不能使用 chunkStatistics 就需要使用page数据计算 |
| if (readAndCalcFromPage()) { |
| return results; |
| } |
| } |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br></div></div><p><code>readAndCalcFromPage</code> 方法是从当前打开的chunk中获取page的数据，并计算聚合结果。当完成所有计算时返回 true，否则返回 false。主要逻辑：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>while (reader.hasNextPage()) { |
| Statistics pageStatistics = reader.currentPageStatistics(); |
| //只有page与其它page不相交时，才能使用 pageStatistics |
| if (pageStatistics != null) { |
| // 判断能否使用 Statistics，并执行计算 |
| .... |
| // 跳过当前page |
| reader.skipCurrentPage(); |
| // 如果已经获取到了所有结果就结束计算 |
| if (isEndCalc()) { |
| return true; |
| } |
| continue; |
| } |
| } |
| // 不能使用 Statistics 时，只能取出所有数据进行计算 |
| BatchData batchData = reader.nextPage(); |
| if (batchData == null || !batchData.hasCurrent()) { |
| continue; |
| } |
| // 如果刚打开的page就超过时间范围，缓存取出来的数据并直接结束计算 |
| if (batchData.currentTime() >= curEndTime) { |
| preCachedData = batchData; |
| return true; |
| } |
| //执行计算 |
| calcFromBatch(batchData); |
| ... |
| } |
| |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br></div></div><p><code>calcFromBatch</code> 方法是对于取出的BatchData数据，遍历所有聚合函数进行计算，主要逻辑为：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>for (Pair<AggregateResult, Integer> result : results) { |
| //如果某个函数已经完成了计算，就不在进行计算了，比如最小值这种计算 |
| if (result.left.isCalculatedAggregationResult()) { |
| continue; |
| } |
| // 执行计算 |
| .... |
| } |
| //判断当前的 batchdata 里的数据是否还能被下次使用，如果能则加到缓存中 |
| if (batchData.getMaxTimestamp() >= curEndTime) { |
| preCachedData = batchData; |
| } |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><h2 id="带值过滤条件的聚合查询"><a href="#带值过滤条件的聚合查询" class="header-anchor">#</a> 带值过滤条件的聚合查询</h2> <p>带值过滤条件的降采样查询逻辑主要在 <code>GroupByWithValueFilterDataSet</code> 类中，该类继承了 <code>GroupByEngineDataSet</code>。</p> <p>该类有如下关键字段：</p> <ul><li><div class="language- line-numbers-mode"><pre class="language-text"><code>private List<IReaderByTimestamp> allDataReaderList |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div></li> <li><p>private GroupByPlan groupByTimePlan</p></li> <li><p>private TimeGenerator timestampGenerator</p></li> <li><p>private long timestamp 用于为下一个 group by 分区缓存 timestamp</p></li> <li><p>private boolean hasCachedTimestamp 用于判断是否有为下一个 group by 分区缓存 timestamp</p></li> <li><p>private int timeStampFetchSize 是 group by 计算 batch 的大小</p></li></ul> <p>首先，在初始化 <code>initGroupBy()</code> 方法中，根据表达式创建 <code>timestampGenerator</code>；然后为每一个时间序列创建一个 <code>SeriesReaderByTimestamp</code>，放到 <code>allDataReaderList</code>列表中</p> <p>初始化完成后，调用 <code>nextWithoutConstraint()</code> 方法更新结果。如果有为下一个 group by 分区缓存 timestamp，且时间符合要求，则将其加入 <code>timestampArray</code> 中，否则直接返回 <code>aggregateResultList</code> 结果；在没有为下一个 group by 分区缓存 timestamp 的情况下，使用 <code>timestampGenerator</code> 进行遍历：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>while (timestampGenerator.hasNext()) { |
| // 调用 constructTimeArrayForOneCal() 方法，得到 timestamp 列表 |
| timeArrayLength = constructTimeArrayForOneCal(timestampArray, timeArrayLength); |
| |
| // 调用 updateResultUsingTimestamps() 方法，使用 timestamp 列表计算聚合结果 |
| for (int i = 0; i < paths.size(); i++) { |
| aggregateResultList.get(i).updateResultUsingTimestamps( |
| timestampArray, timeArrayLength, allDataReaderList.get(i)); |
| } |
| |
| timeArrayLength = 0; |
| // 判断是否到结束 |
| if (timestamp >= curEndTime) { |
| hasCachedTimestamp = true; |
| break; |
| } |
| } |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br></div></div><p>其中的 <code>constructTimeArrayForOneCal()</code> 方法遍历 timestampGenerator 构建 timestamp 列表：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>for (int cnt = 1; cnt < timeStampFetchSize && timestampGenerator.hasNext(); cnt++) { |
| timestamp = timestampGenerator.next(); |
| if (timestamp < curEndTime) { |
| timestampArray[timeArrayLength++] = timestamp; |
| } else { |
| hasCachedTimestamp = true; |
| break; |
| } |
| } |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><h2 id="使用level来汇总降采样的总点数"><a href="#使用level来汇总降采样的总点数" class="header-anchor">#</a> 使用Level来汇总降采样的总点数</h2> <p>降采样后，我们也可以使用level关键字来进一步汇总点数。</p> <p>这个逻辑在 <code>GroupByTimeDataSet</code>类里。</p> <ol><li><p>首先，把所有涉及到的时序按level来进行汇集，最后的路径。</p> <blockquote><p>例如把root.sg1.d1.s0,root.sg1.d2.s1按level=1汇集成root.sg1。</p></blockquote></li> <li><p>然后调用上述的降采样逻辑求出所有时序的总点数信息，这个会返回RowRecord数据结构。</p></li> <li><p>最后，把降采样返回的RowRecord按上述的final paths，进行累加，组合成新的RowRecord。</p> <blockquote><p>例如，把《root.sg1.d1.s0,3》，《root.sg1.d2.s1，4》聚合成《root.sg1，7》</p></blockquote></li></ol> <blockquote><p>注意:</p> <ol><li>这里只支持count操作</li> <li>root的层级level=0</li></ol></blockquote></div> <div class="page-nav"><p class="inner"><span class="prev"> |
| ← |
| <a href="/zh/SystemDesign/DataQuery/AggregationQuery.html" class="prev"> |
| 聚合查询 |
| </a></span> <span class="next"><a href="/zh/SystemDesign/DataQuery/LastQuery.html"> |
| 最近时间戳 Last 查询 |
| </a> |
| → |
| </span></p></div> <p style="text-align: center;">Copyright © 2021 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: #444"> |
| Contact us: Join QQ Group 659990460 | Add friend <i>tietouqiao</i> and be invited to Wechat Group<br> |
| see <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> for more</p></main></div><div class="global-ui"></div></div> |
| <script src="/assets/js/app.c078fe6d.js" defer></script><script src="/assets/js/3.5626571b.js" defer></script><script src="/assets/js/292.2ee40b66.js" defer></script> |
| </body> |
| </html> |
