| <!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 1.6.0"> |
| <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.1c0ab417.css" as="style"><link rel="preload" href="/assets/js/app.a43d7cd0.js" as="script"><link rel="preload" href="/assets/js/3.6210d98e.js" as="script"><link rel="preload" href="/assets/js/256.86cbb101.js" as="script"><link rel="prefetch" href="/assets/js/10.a8c2da4d.js"><link rel="prefetch" href="/assets/js/100.610c16f2.js"><link rel="prefetch" href="/assets/js/101.cb7d6071.js"><link rel="prefetch" href="/assets/js/102.ae495060.js"><link rel="prefetch" href="/assets/js/103.a8df0800.js"><link rel="prefetch" href="/assets/js/104.2245511e.js"><link rel="prefetch" href="/assets/js/105.3f6e6516.js"><link rel="prefetch" href="/assets/js/106.c29577c2.js"><link rel="prefetch" href="/assets/js/107.d1b2cd67.js"><link rel="prefetch" href="/assets/js/108.8ef3a4c5.js"><link rel="prefetch" href="/assets/js/109.dc0fb58e.js"><link rel="prefetch" href="/assets/js/11.a8f8817f.js"><link rel="prefetch" href="/assets/js/110.b714fc01.js"><link rel="prefetch" href="/assets/js/111.a5d11e38.js"><link rel="prefetch" href="/assets/js/112.6d1a395f.js"><link rel="prefetch" href="/assets/js/113.5dfad6f9.js"><link rel="prefetch" href="/assets/js/114.43308969.js"><link rel="prefetch" href="/assets/js/115.8096c93e.js"><link rel="prefetch" href="/assets/js/116.a6976ccd.js"><link rel="prefetch" href="/assets/js/117.f323e27f.js"><link rel="prefetch" href="/assets/js/118.57bb1abd.js"><link rel="prefetch" href="/assets/js/119.c73ae4f0.js"><link rel="prefetch" href="/assets/js/12.d6e39d88.js"><link rel="prefetch" href="/assets/js/120.13871423.js"><link rel="prefetch" href="/assets/js/121.9d905e19.js"><link rel="prefetch" href="/assets/js/122.668d2488.js"><link rel="prefetch" href="/assets/js/123.ce6c2002.js"><link rel="prefetch" href="/assets/js/124.66d50dad.js"><link rel="prefetch" href="/assets/js/125.9f34d14d.js"><link rel="prefetch" href="/assets/js/126.4e916938.js"><link rel="prefetch" href="/assets/js/127.de1c9600.js"><link rel="prefetch" href="/assets/js/128.18945ba9.js"><link rel="prefetch" href="/assets/js/129.e371cf05.js"><link rel="prefetch" href="/assets/js/13.19327a9c.js"><link rel="prefetch" href="/assets/js/130.6f0854cf.js"><link rel="prefetch" href="/assets/js/131.4490139b.js"><link rel="prefetch" href="/assets/js/132.d17b7727.js"><link rel="prefetch" href="/assets/js/133.5d136bd2.js"><link rel="prefetch" href="/assets/js/134.85e21f55.js"><link rel="prefetch" href="/assets/js/135.c2a5c73e.js"><link rel="prefetch" href="/assets/js/136.ea80add8.js"><link rel="prefetch" href="/assets/js/137.162ad739.js"><link rel="prefetch" href="/assets/js/138.003e92a6.js"><link rel="prefetch" href="/assets/js/139.77af0781.js"><link rel="prefetch" href="/assets/js/14.155ff9c5.js"><link rel="prefetch" href="/assets/js/140.9a3b2358.js"><link rel="prefetch" href="/assets/js/141.08896ed8.js"><link rel="prefetch" href="/assets/js/142.8f892360.js"><link rel="prefetch" href="/assets/js/143.c07eb590.js"><link rel="prefetch" href="/assets/js/144.d786614a.js"><link rel="prefetch" href="/assets/js/145.795b9025.js"><link rel="prefetch" href="/assets/js/146.b999e2b1.js"><link rel="prefetch" href="/assets/js/147.ae5efbfc.js"><link rel="prefetch" href="/assets/js/148.55918b45.js"><link rel="prefetch" href="/assets/js/149.963af3d6.js"><link rel="prefetch" href="/assets/js/15.f2dcca51.js"><link rel="prefetch" href="/assets/js/150.7ecfce29.js"><link rel="prefetch" href="/assets/js/151.2cedc233.js"><link rel="prefetch" href="/assets/js/152.5a57be5f.js"><link rel="prefetch" href="/assets/js/153.0269b0ba.js"><link rel="prefetch" href="/assets/js/154.b21f8642.js"><link rel="prefetch" href="/assets/js/155.aa88d113.js"><link rel="prefetch" href="/assets/js/156.d81dea62.js"><link rel="prefetch" href="/assets/js/157.f4c11fdc.js"><link rel="prefetch" href="/assets/js/158.f37d52c1.js"><link rel="prefetch" href="/assets/js/159.698bd399.js"><link rel="prefetch" href="/assets/js/16.68617903.js"><link rel="prefetch" href="/assets/js/160.3cbd628c.js"><link rel="prefetch" href="/assets/js/161.e509f048.js"><link rel="prefetch" href="/assets/js/162.c8a094e6.js"><link rel="prefetch" href="/assets/js/163.3a775f8c.js"><link rel="prefetch" href="/assets/js/164.d2890cfc.js"><link rel="prefetch" href="/assets/js/165.b4b5c056.js"><link rel="prefetch" href="/assets/js/166.dbe88230.js"><link rel="prefetch" href="/assets/js/167.f06c4e8e.js"><link rel="prefetch" href="/assets/js/168.4ba6d0d5.js"><link rel="prefetch" href="/assets/js/169.8db4c44f.js"><link rel="prefetch" href="/assets/js/17.f9c56825.js"><link rel="prefetch" href="/assets/js/170.e0f40101.js"><link rel="prefetch" href="/assets/js/171.02f1c9a7.js"><link rel="prefetch" href="/assets/js/172.23fa5fe7.js"><link rel="prefetch" href="/assets/js/173.3426b1ab.js"><link rel="prefetch" href="/assets/js/174.2912e5dd.js"><link rel="prefetch" href="/assets/js/175.b49e057c.js"><link rel="prefetch" href="/assets/js/176.3fecec61.js"><link rel="prefetch" href="/assets/js/177.120d4f6d.js"><link rel="prefetch" href="/assets/js/178.f31cf22e.js"><link rel="prefetch" href="/assets/js/179.8250f5b4.js"><link rel="prefetch" href="/assets/js/18.6a45243e.js"><link rel="prefetch" href="/assets/js/180.03c29a93.js"><link rel="prefetch" href="/assets/js/181.76d2e48e.js"><link rel="prefetch" href="/assets/js/182.a1289998.js"><link rel="prefetch" href="/assets/js/183.95e8b928.js"><link rel="prefetch" href="/assets/js/184.51ec376a.js"><link rel="prefetch" href="/assets/js/185.7850656d.js"><link rel="prefetch" href="/assets/js/186.46790403.js"><link rel="prefetch" href="/assets/js/187.dba668f4.js"><link rel="prefetch" href="/assets/js/188.9ef76ad8.js"><link rel="prefetch" href="/assets/js/189.e17095d5.js"><link rel="prefetch" href="/assets/js/19.db72f43f.js"><link rel="prefetch" href="/assets/js/190.b06fed0c.js"><link rel="prefetch" href="/assets/js/191.82487132.js"><link rel="prefetch" href="/assets/js/192.6f6ed4ef.js"><link rel="prefetch" href="/assets/js/193.4553db6e.js"><link rel="prefetch" href="/assets/js/194.dc7c8aed.js"><link rel="prefetch" href="/assets/js/195.18a15b0a.js"><link rel="prefetch" href="/assets/js/196.30b5b248.js"><link rel="prefetch" href="/assets/js/197.e10b8a1d.js"><link rel="prefetch" href="/assets/js/198.a5e0c58e.js"><link rel="prefetch" href="/assets/js/199.2c0baf59.js"><link rel="prefetch" href="/assets/js/20.4c74811a.js"><link rel="prefetch" href="/assets/js/200.d07091f7.js"><link rel="prefetch" href="/assets/js/201.1ebc8666.js"><link rel="prefetch" href="/assets/js/202.f5267ff1.js"><link rel="prefetch" href="/assets/js/203.acfb9c3d.js"><link rel="prefetch" href="/assets/js/204.8d928037.js"><link rel="prefetch" href="/assets/js/205.9bc72cf2.js"><link rel="prefetch" href="/assets/js/206.80d7696d.js"><link rel="prefetch" href="/assets/js/207.6298850d.js"><link rel="prefetch" href="/assets/js/208.afe92c6b.js"><link rel="prefetch" href="/assets/js/209.133841c6.js"><link rel="prefetch" href="/assets/js/21.19ce7f11.js"><link rel="prefetch" href="/assets/js/210.132b2f3d.js"><link rel="prefetch" href="/assets/js/211.02812a4d.js"><link rel="prefetch" href="/assets/js/212.4d5ea528.js"><link rel="prefetch" href="/assets/js/213.53e6d733.js"><link rel="prefetch" href="/assets/js/214.730115ce.js"><link rel="prefetch" href="/assets/js/215.37dbe437.js"><link rel="prefetch" href="/assets/js/216.a65b1897.js"><link rel="prefetch" href="/assets/js/217.a0d8d7f2.js"><link rel="prefetch" href="/assets/js/218.ad3bdbec.js"><link rel="prefetch" href="/assets/js/219.4b296837.js"><link rel="prefetch" href="/assets/js/22.9a23de49.js"><link rel="prefetch" href="/assets/js/220.e6548648.js"><link rel="prefetch" href="/assets/js/221.73cc84cf.js"><link rel="prefetch" href="/assets/js/222.6ff0f81e.js"><link rel="prefetch" href="/assets/js/223.e4b3404e.js"><link rel="prefetch" href="/assets/js/224.4e148f22.js"><link rel="prefetch" href="/assets/js/225.7ab00c65.js"><link rel="prefetch" href="/assets/js/226.6ee2800c.js"><link rel="prefetch" href="/assets/js/227.dbafe68f.js"><link rel="prefetch" href="/assets/js/228.3635bbf3.js"><link rel="prefetch" href="/assets/js/229.c8b044a3.js"><link rel="prefetch" href="/assets/js/23.eb7d2c98.js"><link rel="prefetch" href="/assets/js/230.5cd73e63.js"><link rel="prefetch" href="/assets/js/231.b5154f98.js"><link rel="prefetch" href="/assets/js/232.b394b06b.js"><link rel="prefetch" href="/assets/js/233.89870d38.js"><link rel="prefetch" href="/assets/js/234.3626182e.js"><link rel="prefetch" href="/assets/js/235.918055e1.js"><link rel="prefetch" href="/assets/js/236.c5884eb4.js"><link rel="prefetch" href="/assets/js/237.bc5f6c74.js"><link rel="prefetch" href="/assets/js/238.462914c3.js"><link rel="prefetch" href="/assets/js/239.45f73834.js"><link rel="prefetch" href="/assets/js/24.22e7a403.js"><link rel="prefetch" href="/assets/js/240.780a1ce0.js"><link rel="prefetch" href="/assets/js/241.6b01b690.js"><link rel="prefetch" href="/assets/js/242.0c763bc8.js"><link rel="prefetch" href="/assets/js/243.d4c09b4e.js"><link rel="prefetch" href="/assets/js/244.31b37057.js"><link rel="prefetch" href="/assets/js/245.981233f0.js"><link rel="prefetch" href="/assets/js/246.e4c1428a.js"><link rel="prefetch" href="/assets/js/247.e25f44b4.js"><link rel="prefetch" href="/assets/js/248.7bdfd8b2.js"><link rel="prefetch" href="/assets/js/249.d3a237d9.js"><link rel="prefetch" href="/assets/js/25.6410dcd3.js"><link rel="prefetch" href="/assets/js/250.10034fc7.js"><link rel="prefetch" href="/assets/js/251.168761c0.js"><link rel="prefetch" href="/assets/js/252.6f0f4214.js"><link rel="prefetch" href="/assets/js/253.4b794839.js"><link rel="prefetch" href="/assets/js/254.b563d2fa.js"><link rel="prefetch" href="/assets/js/255.7cfd9f1f.js"><link rel="prefetch" href="/assets/js/257.f150714a.js"><link rel="prefetch" href="/assets/js/258.1cf5cfe1.js"><link rel="prefetch" href="/assets/js/259.4e2f6cde.js"><link rel="prefetch" href="/assets/js/26.3bad1fe4.js"><link rel="prefetch" href="/assets/js/260.43d2bf2c.js"><link rel="prefetch" href="/assets/js/261.de64501f.js"><link rel="prefetch" href="/assets/js/262.3fffbe47.js"><link rel="prefetch" href="/assets/js/263.431cfbc4.js"><link rel="prefetch" href="/assets/js/264.3ac3da15.js"><link rel="prefetch" href="/assets/js/265.f6808bd4.js"><link rel="prefetch" href="/assets/js/266.4ca922e8.js"><link rel="prefetch" href="/assets/js/267.43a0858e.js"><link rel="prefetch" href="/assets/js/268.cdfdd162.js"><link rel="prefetch" href="/assets/js/269.bfa60072.js"><link rel="prefetch" href="/assets/js/27.e0436567.js"><link rel="prefetch" href="/assets/js/270.10b63901.js"><link rel="prefetch" href="/assets/js/271.c08237ce.js"><link rel="prefetch" href="/assets/js/272.eb663d76.js"><link rel="prefetch" href="/assets/js/273.286cd5e4.js"><link rel="prefetch" href="/assets/js/274.1e503eb5.js"><link rel="prefetch" href="/assets/js/275.3534c62b.js"><link rel="prefetch" href="/assets/js/276.82fbecb1.js"><link rel="prefetch" href="/assets/js/277.0f5d5705.js"><link rel="prefetch" href="/assets/js/278.6f43457f.js"><link rel="prefetch" href="/assets/js/279.98bcf600.js"><link rel="prefetch" href="/assets/js/28.87ee303f.js"><link rel="prefetch" href="/assets/js/280.b98abe82.js"><link rel="prefetch" href="/assets/js/281.be2dc320.js"><link rel="prefetch" href="/assets/js/282.3f6ca7fc.js"><link rel="prefetch" href="/assets/js/283.2f170354.js"><link rel="prefetch" href="/assets/js/284.6513faa5.js"><link rel="prefetch" href="/assets/js/285.aaf2cbc6.js"><link rel="prefetch" href="/assets/js/286.4fc383e8.js"><link rel="prefetch" href="/assets/js/287.d9029cf5.js"><link rel="prefetch" href="/assets/js/288.135ff5c4.js"><link rel="prefetch" href="/assets/js/289.d33c4d85.js"><link rel="prefetch" href="/assets/js/29.d3d6e6b3.js"><link rel="prefetch" href="/assets/js/290.8c5fb962.js"><link rel="prefetch" href="/assets/js/291.0b9c7751.js"><link rel="prefetch" href="/assets/js/292.54c34e79.js"><link rel="prefetch" href="/assets/js/293.86e62273.js"><link rel="prefetch" href="/assets/js/294.df4b0bc9.js"><link rel="prefetch" href="/assets/js/295.e50b7cd9.js"><link rel="prefetch" href="/assets/js/296.91f8770b.js"><link rel="prefetch" href="/assets/js/297.5e8c5bfa.js"><link rel="prefetch" href="/assets/js/298.b6bbf7c5.js"><link rel="prefetch" href="/assets/js/299.04718448.js"><link rel="prefetch" href="/assets/js/30.3650586b.js"><link rel="prefetch" href="/assets/js/300.bec6a12b.js"><link rel="prefetch" href="/assets/js/301.d50543c3.js"><link rel="prefetch" href="/assets/js/302.8c809032.js"><link rel="prefetch" href="/assets/js/303.4a1071b2.js"><link rel="prefetch" href="/assets/js/304.aafbe597.js"><link rel="prefetch" href="/assets/js/305.66139de5.js"><link rel="prefetch" href="/assets/js/306.6310a4f5.js"><link rel="prefetch" href="/assets/js/307.8a392989.js"><link rel="prefetch" href="/assets/js/308.18595d18.js"><link rel="prefetch" href="/assets/js/309.e67b8dbe.js"><link rel="prefetch" href="/assets/js/31.b94d0bbe.js"><link rel="prefetch" href="/assets/js/310.b1dbbf1c.js"><link rel="prefetch" href="/assets/js/311.f9f34ef3.js"><link rel="prefetch" href="/assets/js/312.98309630.js"><link rel="prefetch" href="/assets/js/313.44844612.js"><link rel="prefetch" href="/assets/js/314.a3b20b70.js"><link rel="prefetch" href="/assets/js/315.b4af0dbe.js"><link rel="prefetch" href="/assets/js/316.11be37cf.js"><link rel="prefetch" href="/assets/js/317.8bfdda93.js"><link rel="prefetch" href="/assets/js/318.663ffbcc.js"><link rel="prefetch" href="/assets/js/319.59af0d55.js"><link rel="prefetch" href="/assets/js/32.ff896413.js"><link rel="prefetch" href="/assets/js/320.9ed2a82c.js"><link rel="prefetch" href="/assets/js/321.fac3ebc4.js"><link rel="prefetch" href="/assets/js/322.96d349d2.js"><link rel="prefetch" href="/assets/js/323.2fcdfd96.js"><link rel="prefetch" href="/assets/js/324.a19966ff.js"><link rel="prefetch" href="/assets/js/325.987eaec4.js"><link rel="prefetch" href="/assets/js/326.18894f23.js"><link rel="prefetch" href="/assets/js/327.2014e08f.js"><link rel="prefetch" href="/assets/js/328.86e52e6b.js"><link rel="prefetch" href="/assets/js/329.0424d7d5.js"><link rel="prefetch" href="/assets/js/33.95a3ac05.js"><link rel="prefetch" href="/assets/js/330.40f26bb0.js"><link rel="prefetch" href="/assets/js/331.65ee89c2.js"><link rel="prefetch" href="/assets/js/332.31da3cb2.js"><link rel="prefetch" href="/assets/js/333.793650ee.js"><link rel="prefetch" href="/assets/js/334.63832503.js"><link rel="prefetch" href="/assets/js/335.62c60028.js"><link rel="prefetch" href="/assets/js/336.a520628c.js"><link rel="prefetch" href="/assets/js/337.236ce253.js"><link rel="prefetch" href="/assets/js/338.88377897.js"><link rel="prefetch" href="/assets/js/339.88b3d8a2.js"><link rel="prefetch" href="/assets/js/34.e93e2e55.js"><link rel="prefetch" href="/assets/js/340.5b139ee6.js"><link rel="prefetch" href="/assets/js/341.9fc8c6ed.js"><link rel="prefetch" href="/assets/js/342.3ad73777.js"><link rel="prefetch" href="/assets/js/343.2c8ba853.js"><link rel="prefetch" href="/assets/js/344.d9f7d184.js"><link rel="prefetch" href="/assets/js/345.59284c96.js"><link rel="prefetch" href="/assets/js/346.bb62fee3.js"><link rel="prefetch" href="/assets/js/347.a504768f.js"><link rel="prefetch" href="/assets/js/348.f7fc33f2.js"><link rel="prefetch" href="/assets/js/349.a0969f85.js"><link rel="prefetch" href="/assets/js/35.2eaa786a.js"><link rel="prefetch" href="/assets/js/350.8be88652.js"><link rel="prefetch" href="/assets/js/351.a0134bc5.js"><link rel="prefetch" href="/assets/js/352.7c6b05f5.js"><link rel="prefetch" href="/assets/js/353.13f82a67.js"><link rel="prefetch" href="/assets/js/354.7a15a639.js"><link rel="prefetch" href="/assets/js/355.ce87b8a8.js"><link rel="prefetch" href="/assets/js/356.7f271afc.js"><link rel="prefetch" href="/assets/js/357.cd4e6ad5.js"><link rel="prefetch" href="/assets/js/358.231646f5.js"><link rel="prefetch" href="/assets/js/359.951751b8.js"><link rel="prefetch" href="/assets/js/36.0eb14751.js"><link rel="prefetch" href="/assets/js/360.d10a92ff.js"><link rel="prefetch" href="/assets/js/361.30a528c6.js"><link rel="prefetch" href="/assets/js/362.605a4856.js"><link rel="prefetch" href="/assets/js/363.4b0724ed.js"><link rel="prefetch" href="/assets/js/364.09e0ac23.js"><link rel="prefetch" href="/assets/js/365.6cbdb6bb.js"><link rel="prefetch" href="/assets/js/366.f3df5cb3.js"><link rel="prefetch" href="/assets/js/367.5dc304a0.js"><link rel="prefetch" href="/assets/js/368.cfe55d3a.js"><link rel="prefetch" href="/assets/js/369.122e17a6.js"><link rel="prefetch" href="/assets/js/37.373de478.js"><link rel="prefetch" href="/assets/js/370.57e7ca05.js"><link rel="prefetch" href="/assets/js/371.aed8699f.js"><link rel="prefetch" href="/assets/js/372.1c47c97c.js"><link rel="prefetch" href="/assets/js/373.9d2cee25.js"><link rel="prefetch" href="/assets/js/374.0e15cf2e.js"><link rel="prefetch" href="/assets/js/375.d505f167.js"><link rel="prefetch" href="/assets/js/376.5c7a7c26.js"><link rel="prefetch" href="/assets/js/377.a4a94146.js"><link rel="prefetch" href="/assets/js/378.4147bf94.js"><link rel="prefetch" href="/assets/js/379.d4ee40ad.js"><link rel="prefetch" href="/assets/js/38.ab334ffd.js"><link rel="prefetch" href="/assets/js/380.6fa857a5.js"><link rel="prefetch" href="/assets/js/381.2aeee47a.js"><link rel="prefetch" href="/assets/js/382.630fed60.js"><link rel="prefetch" href="/assets/js/383.e6921012.js"><link rel="prefetch" href="/assets/js/384.57717d76.js"><link rel="prefetch" href="/assets/js/385.b4355c7e.js"><link rel="prefetch" href="/assets/js/386.5e7b9753.js"><link rel="prefetch" href="/assets/js/387.c752e45f.js"><link rel="prefetch" href="/assets/js/388.05e04b1c.js"><link rel="prefetch" href="/assets/js/389.a8ad271f.js"><link rel="prefetch" href="/assets/js/39.409d903d.js"><link rel="prefetch" href="/assets/js/390.560fbe59.js"><link rel="prefetch" href="/assets/js/391.4fc3f261.js"><link rel="prefetch" href="/assets/js/392.b409a196.js"><link rel="prefetch" href="/assets/js/393.043b9fb3.js"><link rel="prefetch" href="/assets/js/394.07d26f84.js"><link rel="prefetch" href="/assets/js/395.ac86423f.js"><link rel="prefetch" href="/assets/js/396.096b1b5d.js"><link rel="prefetch" href="/assets/js/397.c36e4f7d.js"><link rel="prefetch" href="/assets/js/398.62aed540.js"><link rel="prefetch" href="/assets/js/399.081d7ba5.js"><link rel="prefetch" href="/assets/js/4.e53d8224.js"><link rel="prefetch" href="/assets/js/40.8d1d6eb3.js"><link rel="prefetch" href="/assets/js/400.baebd974.js"><link rel="prefetch" href="/assets/js/401.297d2159.js"><link rel="prefetch" href="/assets/js/402.37a81f3c.js"><link rel="prefetch" href="/assets/js/403.9ddf70fc.js"><link rel="prefetch" href="/assets/js/404.bb1cf823.js"><link rel="prefetch" href="/assets/js/405.c1f982a3.js"><link rel="prefetch" href="/assets/js/406.cef2382f.js"><link rel="prefetch" href="/assets/js/407.8ce0ef14.js"><link rel="prefetch" href="/assets/js/408.70093677.js"><link rel="prefetch" href="/assets/js/409.8470a10f.js"><link rel="prefetch" href="/assets/js/41.a0b11040.js"><link rel="prefetch" href="/assets/js/410.7fcfbb14.js"><link rel="prefetch" href="/assets/js/411.12656519.js"><link rel="prefetch" href="/assets/js/412.4ed961de.js"><link rel="prefetch" href="/assets/js/413.fb18f466.js"><link rel="prefetch" href="/assets/js/414.52ae334e.js"><link rel="prefetch" href="/assets/js/415.bf1d3eef.js"><link rel="prefetch" href="/assets/js/416.bfb61bc5.js"><link rel="prefetch" href="/assets/js/417.693a17bd.js"><link rel="prefetch" href="/assets/js/418.2a62e26f.js"><link rel="prefetch" href="/assets/js/419.af18f800.js"><link rel="prefetch" href="/assets/js/42.d7b5cb69.js"><link rel="prefetch" href="/assets/js/420.96bf44c3.js"><link rel="prefetch" href="/assets/js/421.d40d2a5b.js"><link rel="prefetch" href="/assets/js/422.d4aa9626.js"><link rel="prefetch" href="/assets/js/423.2c29f7aa.js"><link rel="prefetch" href="/assets/js/424.30db9de9.js"><link rel="prefetch" href="/assets/js/425.9c8b4212.js"><link rel="prefetch" href="/assets/js/426.d258d015.js"><link rel="prefetch" href="/assets/js/427.e5c806f7.js"><link rel="prefetch" href="/assets/js/428.35490fd4.js"><link rel="prefetch" href="/assets/js/429.71b82b78.js"><link rel="prefetch" href="/assets/js/43.070ce713.js"><link rel="prefetch" href="/assets/js/430.cedb78bd.js"><link rel="prefetch" href="/assets/js/431.37ca9c54.js"><link rel="prefetch" href="/assets/js/432.828817f0.js"><link rel="prefetch" href="/assets/js/433.645623f7.js"><link rel="prefetch" href="/assets/js/434.7bb50d9b.js"><link rel="prefetch" href="/assets/js/435.f39a1847.js"><link rel="prefetch" href="/assets/js/436.63593e43.js"><link rel="prefetch" href="/assets/js/437.c596b089.js"><link rel="prefetch" href="/assets/js/438.240d8e15.js"><link rel="prefetch" href="/assets/js/439.feaf2e3b.js"><link rel="prefetch" href="/assets/js/44.127fc92f.js"><link rel="prefetch" href="/assets/js/440.9580ce02.js"><link rel="prefetch" href="/assets/js/441.b9d60f11.js"><link rel="prefetch" href="/assets/js/442.5ee1e745.js"><link rel="prefetch" href="/assets/js/443.b130f757.js"><link rel="prefetch" href="/assets/js/444.8e1416de.js"><link rel="prefetch" href="/assets/js/445.db2ad3e4.js"><link rel="prefetch" href="/assets/js/446.908a7437.js"><link rel="prefetch" href="/assets/js/447.569f186b.js"><link rel="prefetch" href="/assets/js/448.cfa84110.js"><link rel="prefetch" href="/assets/js/449.8a975324.js"><link rel="prefetch" href="/assets/js/45.aa6f26c9.js"><link rel="prefetch" href="/assets/js/450.db91d3af.js"><link rel="prefetch" href="/assets/js/451.8c67130b.js"><link rel="prefetch" href="/assets/js/46.d987e0bb.js"><link rel="prefetch" href="/assets/js/47.b175ddf4.js"><link rel="prefetch" href="/assets/js/48.1c23dfdd.js"><link rel="prefetch" href="/assets/js/49.5be54faf.js"><link rel="prefetch" href="/assets/js/5.e17246d6.js"><link rel="prefetch" href="/assets/js/50.b1da13e4.js"><link rel="prefetch" href="/assets/js/51.a89ccc8f.js"><link rel="prefetch" href="/assets/js/52.7549ee24.js"><link rel="prefetch" href="/assets/js/53.a5101355.js"><link rel="prefetch" href="/assets/js/54.ca16bf1e.js"><link rel="prefetch" href="/assets/js/55.088c245a.js"><link rel="prefetch" href="/assets/js/56.b04f7476.js"><link rel="prefetch" href="/assets/js/57.52759a0c.js"><link rel="prefetch" href="/assets/js/58.11d3f0dd.js"><link rel="prefetch" href="/assets/js/59.c0d44170.js"><link rel="prefetch" href="/assets/js/6.b497f2de.js"><link rel="prefetch" href="/assets/js/60.f4a5b3ce.js"><link rel="prefetch" href="/assets/js/61.69a0f8ec.js"><link rel="prefetch" href="/assets/js/62.f2884dc3.js"><link rel="prefetch" href="/assets/js/63.2200cd75.js"><link rel="prefetch" href="/assets/js/64.d1e195f6.js"><link rel="prefetch" href="/assets/js/65.f0196f55.js"><link rel="prefetch" href="/assets/js/66.a1d8a358.js"><link rel="prefetch" href="/assets/js/67.eb3af313.js"><link rel="prefetch" href="/assets/js/68.fc37b146.js"><link rel="prefetch" href="/assets/js/69.8a3039c1.js"><link rel="prefetch" href="/assets/js/7.050bd105.js"><link rel="prefetch" href="/assets/js/70.18f2ac49.js"><link rel="prefetch" href="/assets/js/71.f9c04e4e.js"><link rel="prefetch" href="/assets/js/72.72bb4f92.js"><link rel="prefetch" href="/assets/js/73.93a0e56f.js"><link rel="prefetch" href="/assets/js/74.94b0e415.js"><link rel="prefetch" href="/assets/js/75.0efe5bd8.js"><link rel="prefetch" href="/assets/js/76.411a149b.js"><link rel="prefetch" href="/assets/js/77.93f3a85b.js"><link rel="prefetch" href="/assets/js/78.e721ad23.js"><link rel="prefetch" href="/assets/js/79.52b8d1bb.js"><link rel="prefetch" href="/assets/js/8.ca5874dd.js"><link rel="prefetch" href="/assets/js/80.f7ff9764.js"><link rel="prefetch" href="/assets/js/81.b3fb800e.js"><link rel="prefetch" href="/assets/js/82.cda965c9.js"><link rel="prefetch" href="/assets/js/83.67402967.js"><link rel="prefetch" href="/assets/js/84.7111aac5.js"><link rel="prefetch" href="/assets/js/85.98a2cf19.js"><link rel="prefetch" href="/assets/js/86.08ccbd30.js"><link rel="prefetch" href="/assets/js/87.1d9976a5.js"><link rel="prefetch" href="/assets/js/88.4c2af5cc.js"><link rel="prefetch" href="/assets/js/89.be23dd95.js"><link rel="prefetch" href="/assets/js/9.448d01b4.js"><link rel="prefetch" href="/assets/js/90.bfe2cd95.js"><link rel="prefetch" href="/assets/js/91.c3c25fa1.js"><link rel="prefetch" href="/assets/js/92.043be796.js"><link rel="prefetch" href="/assets/js/93.59f34557.js"><link rel="prefetch" href="/assets/js/94.52822aff.js"><link rel="prefetch" href="/assets/js/95.a9490191.js"><link rel="prefetch" href="/assets/js/96.517f15b2.js"><link rel="prefetch" href="/assets/js/97.27be6b97.js"><link rel="prefetch" href="/assets/js/98.05e0ebd7.js"><link rel="prefetch" href="/assets/js/99.8b7ca3c5.js"><link rel="prefetch" href="/assets/js/vendors~docsearch.3b3aacb0.js"> |
| <link rel="stylesheet" href="/assets/css/0.styles.1c0ab417.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/V0.10.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="/zh/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="/" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/SystemDesign/DataQuery/OrderByTimeQuery.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 |
| <svg xmlns="http://www.w3.org/2000/svg" aria-labelledby="outbound-link-title" role="img" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><title id="outbound-link-title">(opens new window)</title> <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></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/V0.10.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="/zh/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="/" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/SystemDesign/DataQuery/OrderByTimeQuery.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 |
| <svg xmlns="http://www.w3.org/2000/svg" aria-labelledby="outbound-link-title" role="img" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><title id="outbound-link-title">(opens new window)</title> <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></a></nav> <ul class="sidebar-links"><li><section class="sidebar-group depth-0"><p class="sidebar-heading open"><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"><span>数据查询</span> <span class="arrow right"></span></p> <!----></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="按时间倒序查询"><a href="#按时间倒序查询" class="header-anchor">#</a> 按时间倒序查询</h1> <h2 id="实现原理"><a href="#实现原理" class="header-anchor">#</a> 实现原理</h2> <p>倒序分为 3 个维度来实现，由内核层到用户层分别为: <code>TsFile</code>、<code>BatchData</code>、<code>数据集</code>.</p> <ol><li><code>TsFile</code> 是用来存储所有原始数据的文件格式，在存储时分为 <code>顺序文件</code> 和 <code>乱序文件</code>. |
| <code>ChunkData</code> 是 <code>TsFile</code> 中的基本数据块，保存了具体某一个测点的数据，且<strong>数据是按照时间升序存储的</strong>.</li> <li><code>BatchData</code> 是基础数据交换结构，无论是从文件系统还是缓存读出的数据都会被转换成 <code>BatchData</code> 结构.</li> <li><code>数据集</code> 是封装根据用户输入的 <code>SQL</code> 语句的结果集格式，转换和封装 <code>BatchData</code> 中的数据。</li></ol> <p>实际系统需要考虑的方面会更多，但主要为以上 3 点。 |
| 下面分别介绍各个层面如何实现基于时间的倒序查询:</p> <h2 id="tsfile"><a href="#tsfile" class="header-anchor">#</a> TsFile</h2> <p>1.<code>TsFile</code> 在文件末尾存储了各个测点在文件中的最小时间(开始时间)和最大时间(结束时间)， |
| 所以当我们按照开始时间升序排列文件并读取数据时,是升序读取;当使用结束时间倒序排列文件 |
| (<strong>顺序文件也可以使用开始时间倒序排列</strong>)并读取数据时,是<strong>伪倒序读取</strong>(因为文件内依然是升序存储的),数据示例:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code> 按照开始时间升序排列 (1,6) |
| +---TsFile1---+ +---TsFile2---+ |
| | 1,2,3,4,5 | | 6,7,8,9,10 | |
| +-------------+ +-------------+ |
| |
| 按照结束降序排列 (10,5) |
| +---TsFile2---+ +---TsFile1---+ |
| | 6,7,8,9,10 | | 1,2,3,4,5 | |
| +-------------+ +-------------+ |
| </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><p>2.上面的示例只描述了顺序文件，乱序文件的特点是: 文件中存储的数据与其他文件的数据存在相交， |
| 不仅仅和顺序文件相交，乱序和乱序文件之间也可能相交。</p> <div class="language- line-numbers-mode"><pre class="language-text"><code> +---TsFile1---+ +---TsFile2---+ |
| | 1,2,3,4,5 | | 6,7,8,9,10 | |
| +-------------+ +-------------+ |
| +--------------unseq1-----------+ |
| | 2,11 | |
| +-------------------------------+ |
| +-unseq2-+ |
| | 3,4,5 | |
| +--------+ |
| |
| </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></div></div><p>3.对于<strong>相交</strong>的部分，需要使用<code>多路归并</code>查询出最终结果。具体处理细节可以参见<a href="/zh/SystemDesign/DataQuery/SeriesReader.html">SeriesReader</a>.</p> <p>4.对于文件层而言，我们抽象出了<code>TimeOrderUtils</code>，用来完成对升序、降序不同实现的方法提取。</p> <div class="language-java line-numbers-mode"><pre class="language-java"><code> <span class="token keyword">public</span> <span class="token keyword">interface</span> <span class="token class-name">TimeOrderUtils</span> <span class="token punctuation">{</span> |
| <span class="token comment">//排序使用的字段，升序使用开始时间，降序使用结束时间。</span> |
| <span class="token comment">//TsFileResource面对文件相关，Statistics面向Chunk和Page相关</span> |
| <span class="token keyword">long</span> <span class="token function">getOrderTime</span><span class="token punctuation">(</span><span class="token class-name">Statistics</span> statistics<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">long</span> <span class="token function">getOrderTime</span><span class="token punctuation">(</span><span class="token class-name">TsFileResource</span> fileResource<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">//判断是否相交使用的时间依据，升序使用结束时间，降序使用开始时间</span> |
| <span class="token keyword">long</span> <span class="token function">getOverlapCheckTime</span><span class="token punctuation">(</span><span class="token class-name">Statistics</span> range<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">//根据提供的时间判断是否相交，left为依据时间，right为要判断的文件</span> |
| <span class="token keyword">boolean</span> <span class="token function">isOverlapped</span><span class="token punctuation">(</span><span class="token class-name">Statistics</span> left<span class="token punctuation">,</span> <span class="token class-name">Statistics</span> right<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">boolean</span> <span class="token function">isOverlapped</span><span class="token punctuation">(</span><span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token class-name">Statistics</span> right<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token keyword">boolean</span> <span class="token function">isOverlapped</span><span class="token punctuation">(</span><span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token class-name">TsFileResource</span> right<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">//对于有序文件的遍历规则，升序时正序遍历，降序时倒序遍历</span> |
| <span class="token class-name">TsFileResource</span> <span class="token function">getNextSeqFileResource</span><span class="token punctuation">(</span><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">TsFileResource</span><span class="token punctuation">></span></span> seqResources<span class="token punctuation">,</span> <span class="token keyword">boolean</span> isDelete<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">//对于所有文件层的临时缓存排序规则的实现</span> |
| <span class="token generics"><span class="token punctuation"><</span><span class="token class-name">T</span><span class="token punctuation">></span></span> <span class="token class-name">Comparator</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">T</span><span class="token punctuation">></span></span> <span class="token function">comparingLong</span><span class="token punctuation">(</span><span class="token class-name">ToLongFunction</span><span class="token generics"><span class="token punctuation"><</span><span class="token operator">?</span> <span class="token keyword">super</span> <span class="token class-name">T</span><span class="token punctuation">></span></span> keyExtractor<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">//循环读取数据时判断是否到达了当前设置的停止点</span> |
| <span class="token keyword">boolean</span> <span class="token function">isExcessEndpoint</span><span class="token punctuation">(</span><span class="token keyword">long</span> time<span class="token punctuation">,</span> <span class="token keyword">long</span> endpointTime<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| |
| <span class="token comment">//或许当前使用的排序方式</span> |
| <span class="token keyword">boolean</span> <span class="token function">getAscending</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </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></div></div><p>5.完成了上述步骤，倒序取出来的数据如下：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>6,7,8,9,10,1,2,3,4,5 |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这是因为数据在Chunk、Page、缓存中都是升序存储，所以转移到 <code>BatchData</code> 中查看就是示例中的样子。</p> <h2 id="batchdata"><a href="#batchdata" class="header-anchor">#</a> BatchData</h2> <p>1.为了兼容原有的文件读取数据方式，所以在数据放到 <code>BatchData</code> 之后倒序读取集合里的数据就可以得到最终结果。</p> <p>BatchData类似一个二维数组的格式，封装了写入和读取的方法，对于倒序，抽象了下面的子类：</p> <div class="language-java line-numbers-mode"><pre class="language-java"><code> |
| <span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">DescBatchData</span> <span class="token keyword">extends</span> <span class="token class-name">BatchData</span> <span class="token punctuation">{</span> |
| <span class="token comment">//判断是否还有值，正序时候判断是否读到写入的size位置，倒序就是判断是否读到了0的位置</span> |
| <span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">hasCurrent</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token comment">//指针移动到下一个数据，正序为 index+1 操作， 倒序为 index-1 操作</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">next</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token comment">//重制指针位置，正序为重制到0，倒序重制到数据写入位置</span> |
| <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">resetBatchData</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token comment">//就像是Nio中的Buffer类的flip操作，在数据写入完成时做的操作，为读取做好准备</span> |
| <span class="token keyword">public</span> <span class="token class-name">BatchData</span> <span class="token function">flip</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token comment">//使用具体时间获取值，正序时index从0到size遍历，倒序时从size到0遍历</span> |
| <span class="token keyword">public</span> <span class="token class-name">Object</span> <span class="token function">getValueInTimestamp</span><span class="token punctuation">(</span><span class="token keyword">long</span> time<span class="token punctuation">)</span><span class="token punctuation">;</span> |
| <span class="token punctuation">}</span> |
| </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></div></div><p>2.在需要倒序处理数据的位置构建<code>DescBatchData</code>类，为此，特意设计了一个<code>BatchDataFactory</code>类， |
| 根据ascending参数判断生产哪个类型的BatchData。</p> <p>3.因为<code>MergeReader</code>使用了<code>PageReader</code>，所以在降序模式的时候数据会被倒序读出来(如下):</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>5 4 3 2 1 |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>这种情况会使得<code>BatchData</code>使用<code>getValueInTimestamp</code>方法变得困难(因为在正序模式的时候默认为越往后的数据时间越大， |
| 倒序模式的时候越后时间越小)，但是按照如上数据示例无论在哪种模式下，都是违反了期望的数据时间比较，所以，新增了一个 |
| <code>getValueInTimestamp(long time, BiFunction<Long, Long, Boolean> compare)</code>方法， |
| 让不同的使用场景抉择基于时间的数据查找方式。</p> <p>4.至此数据从磁盘和缓存中取出的数据都是严格按照时间排序的了。</p> <h2 id="数据集"><a href="#数据集" class="header-anchor">#</a> 数据集</h2> <p>1.原始数据查询</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> <span class="token operator">*</span> <span class="token keyword">from</span> root <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> |
| <span class="token keyword">select</span> <span class="token operator">*</span> <span class="token keyword">from</span> root <span class="token keyword">where</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>d1<span class="token punctuation">.</span>s1<span class="token operator">></span><span class="token number">100</span> <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> |
| <span class="token keyword">select</span> <span class="token operator">*</span> <span class="token keyword">from</span> root <span class="token keyword">where</span> <span class="token keyword">time</span> <span class="token operator">></span><span class="token number">100</span> <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> |
| </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></div></div><p>原始数据查询中，只要向<code>SeriesReader</code>传递了正确的ascending参数就能得到正确的结果。</p> <p>2.GroupBy</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> max_time<span class="token punctuation">(</span><span class="token operator">*</span><span class="token punctuation">)</span> <span class="token keyword">from</span> root <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 number">10</span><span class="token punctuation">]</span><span class="token punctuation">,</span><span class="token number">2</span>ms<span class="token punctuation">)</span> <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>如上所示的Sql中,groupBy查询的区间分别为:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>[0-2),[2-4),[4-6),[6-8),[8-10) |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>倒序查询只需要将时间计算的过程修改为:</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>[8-10),[6-8),[4-6),[2-4),[0-2) |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><blockquote><p>计算方法为:</p> <p>((结束时间-开始时间)/步长值） 结果向上取整，得到的值为GroupBy中会发生的遍历次数(记为i)。</p> <p>(步长 * (i-1) + 开始时间) 结果为第i次遍历的开始时间值。</p></blockquote> <p>对于BatchData中的数据大于每次遍历的结束时间时，进行skip，然后对 <code>AggregateResult</code> 新增 |
| minBound计算限制,限制为第i次遍历的开始时间值， |
| <strong>数据无论是正序还是倒序遍历对于<code>AggregateResult</code>的结果是等价的</strong>.</p> <p>3.GroupByFill</p> <div class="language-sql line-numbers-mode"><pre class="language-sql"><code><span class="token keyword">select</span> last_value<span class="token punctuation">(</span>s0<span class="token punctuation">)</span> <span class="token keyword">from</span> root<span class="token punctuation">.</span>ln<span class="token punctuation">.</span>d1 <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 number">5</span><span class="token punctuation">]</span><span class="token punctuation">,</span><span class="token number">1</span>ms<span class="token punctuation">)</span> fill <span class="token punctuation">(</span>int32<span class="token punctuation">[</span>Previous<span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token keyword">order</span> <span class="token keyword">by</span> <span class="token keyword">time</span> <span class="token keyword">desc</span> |
| </code></pre> <div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>对于升序的插值计算, 在 <code>GroupByFillDataSet</code> 中做了前值缓存，当本次查询的值不为空时，更新缓存; |
| 为空时使用缓存中的数据。</p> <p>对于降序查询，因为数据在倒序遍历，并不知道它的前值是多少，所以为 <code>GroupByEngineDataSet</code> |
| 抽象了 <code>peekNextNotNullValue</code> 方法，继续往前执行，一直查找到一个不为空的值返回。并将该值缓存到 |
| <code>GroupByFillDataSet</code> 中并遵从升序的补值方法，到当前的循环开始时间小于缓存的时间时缓存失效。</p> <p>4.Last |
| 在<code>LastQueryExecutor</code>中，一次性将所有的结果集封装在了一个List中， |
| 当倒序时将List中的数据根据时间进行一次排序,就得到了结果,详情见<code>ListDataSet</code>.</p></div> <!----> <p style="text-align: center;">Copyright © 2020 The Apache Software Foundation.<br> |
| Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p></main></div><div class="global-ui"></div></div> |
| <script src="/assets/js/app.a43d7cd0.js" defer></script><script src="/assets/js/3.6210d98e.js" defer></script><script src="/assets/js/256.86cbb101.js" defer></script> |
| </body> |
| </html> |
