| <!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.f7fca28c.css" as="style"><link rel="preload" href="/assets/js/app.13a2c569.js" as="script"><link rel="preload" href="/assets/js/3.7fccac46.js" as="script"><link rel="preload" href="/assets/js/354.d811ac0e.js" as="script"><link rel="prefetch" href="/assets/js/10.61872ae5.js"><link rel="prefetch" href="/assets/js/100.cd07fbb4.js"><link rel="prefetch" href="/assets/js/101.7b887a78.js"><link rel="prefetch" href="/assets/js/102.888ac47b.js"><link rel="prefetch" href="/assets/js/103.edff174f.js"><link rel="prefetch" href="/assets/js/104.f049af68.js"><link rel="prefetch" href="/assets/js/105.f7c9efe5.js"><link rel="prefetch" href="/assets/js/106.2ba6adb1.js"><link rel="prefetch" href="/assets/js/107.d676f1a5.js"><link rel="prefetch" href="/assets/js/108.c3799be3.js"><link rel="prefetch" href="/assets/js/109.22c12024.js"><link rel="prefetch" href="/assets/js/11.a080efae.js"><link rel="prefetch" href="/assets/js/110.e988abeb.js"><link rel="prefetch" href="/assets/js/111.70e5507a.js"><link rel="prefetch" href="/assets/js/112.7e40d306.js"><link rel="prefetch" href="/assets/js/113.5f9eed75.js"><link rel="prefetch" href="/assets/js/114.12676666.js"><link rel="prefetch" href="/assets/js/115.de7d0451.js"><link rel="prefetch" href="/assets/js/116.9241daf0.js"><link rel="prefetch" href="/assets/js/117.f1572c4d.js"><link rel="prefetch" href="/assets/js/118.e8829e92.js"><link rel="prefetch" href="/assets/js/119.0b0c33f8.js"><link rel="prefetch" href="/assets/js/12.454ce3d8.js"><link rel="prefetch" href="/assets/js/120.0bf117bb.js"><link rel="prefetch" href="/assets/js/121.4ecd8344.js"><link rel="prefetch" href="/assets/js/122.f3a6aea0.js"><link rel="prefetch" href="/assets/js/123.4945f91b.js"><link rel="prefetch" href="/assets/js/124.41877e73.js"><link rel="prefetch" href="/assets/js/125.85775a08.js"><link rel="prefetch" href="/assets/js/126.60bc16f9.js"><link rel="prefetch" href="/assets/js/127.64f37463.js"><link rel="prefetch" href="/assets/js/128.bf1e94f3.js"><link rel="prefetch" href="/assets/js/129.66d9bb2b.js"><link rel="prefetch" href="/assets/js/13.c58bffc8.js"><link rel="prefetch" href="/assets/js/130.59874ca0.js"><link rel="prefetch" href="/assets/js/131.f9d5e913.js"><link rel="prefetch" href="/assets/js/132.a7e3ad59.js"><link rel="prefetch" href="/assets/js/133.25bc611b.js"><link rel="prefetch" href="/assets/js/134.031b80a3.js"><link rel="prefetch" href="/assets/js/135.63c51cd4.js"><link rel="prefetch" href="/assets/js/136.3035a447.js"><link rel="prefetch" href="/assets/js/137.f04f53d6.js"><link rel="prefetch" href="/assets/js/138.0d77670b.js"><link rel="prefetch" href="/assets/js/139.a4687aa3.js"><link rel="prefetch" href="/assets/js/14.939be0f9.js"><link rel="prefetch" href="/assets/js/140.1c3b9c8e.js"><link rel="prefetch" href="/assets/js/141.85a83839.js"><link rel="prefetch" href="/assets/js/142.7d8ad627.js"><link rel="prefetch" href="/assets/js/143.fbdc020f.js"><link rel="prefetch" href="/assets/js/144.d6b9f34b.js"><link rel="prefetch" href="/assets/js/145.4a65f13c.js"><link rel="prefetch" href="/assets/js/146.d6f1ef22.js"><link rel="prefetch" href="/assets/js/147.e33fe78c.js"><link rel="prefetch" href="/assets/js/148.1f001b51.js"><link rel="prefetch" href="/assets/js/149.d802d76b.js"><link rel="prefetch" href="/assets/js/15.843fe861.js"><link rel="prefetch" href="/assets/js/150.bf6e4446.js"><link rel="prefetch" href="/assets/js/151.1a3a9ecf.js"><link rel="prefetch" href="/assets/js/152.ca32b0c3.js"><link rel="prefetch" href="/assets/js/153.74bb0871.js"><link rel="prefetch" href="/assets/js/154.2e0647d0.js"><link rel="prefetch" href="/assets/js/155.d1c42f9d.js"><link rel="prefetch" href="/assets/js/156.dd3ef885.js"><link rel="prefetch" href="/assets/js/157.d0fa5d7e.js"><link rel="prefetch" href="/assets/js/158.d8ac80b6.js"><link rel="prefetch" href="/assets/js/159.7daff5e5.js"><link rel="prefetch" href="/assets/js/16.8d6c0ada.js"><link rel="prefetch" href="/assets/js/160.334e1792.js"><link rel="prefetch" href="/assets/js/161.ea35ffd3.js"><link rel="prefetch" href="/assets/js/162.a3e43ef6.js"><link rel="prefetch" href="/assets/js/163.63e5a86d.js"><link rel="prefetch" href="/assets/js/164.014d76e1.js"><link rel="prefetch" href="/assets/js/165.93a410f4.js"><link rel="prefetch" href="/assets/js/166.a5f56f78.js"><link rel="prefetch" href="/assets/js/167.51507116.js"><link rel="prefetch" href="/assets/js/168.34704422.js"><link rel="prefetch" href="/assets/js/169.0251848a.js"><link rel="prefetch" href="/assets/js/17.efe29df6.js"><link rel="prefetch" href="/assets/js/170.f9084320.js"><link rel="prefetch" href="/assets/js/171.ba1d2df7.js"><link rel="prefetch" href="/assets/js/172.8a7cd300.js"><link rel="prefetch" href="/assets/js/173.4d45b322.js"><link rel="prefetch" href="/assets/js/174.14ce1f9d.js"><link rel="prefetch" href="/assets/js/175.8ba92c6d.js"><link rel="prefetch" href="/assets/js/176.f83d84c6.js"><link rel="prefetch" href="/assets/js/177.e3ca589e.js"><link rel="prefetch" href="/assets/js/178.e26e2799.js"><link rel="prefetch" href="/assets/js/179.80f9f4ee.js"><link rel="prefetch" href="/assets/js/18.ec2f64fe.js"><link rel="prefetch" href="/assets/js/180.16830f5a.js"><link rel="prefetch" href="/assets/js/181.6c2dd09c.js"><link rel="prefetch" href="/assets/js/182.4b20bd4d.js"><link rel="prefetch" href="/assets/js/183.f1a9f3d0.js"><link rel="prefetch" href="/assets/js/184.4e828571.js"><link rel="prefetch" href="/assets/js/185.be70dd25.js"><link rel="prefetch" href="/assets/js/186.ddb365dd.js"><link rel="prefetch" href="/assets/js/187.f66f7f93.js"><link rel="prefetch" href="/assets/js/188.6a88c397.js"><link rel="prefetch" href="/assets/js/189.28897e83.js"><link rel="prefetch" href="/assets/js/19.e46591ce.js"><link rel="prefetch" href="/assets/js/190.a85849f1.js"><link rel="prefetch" href="/assets/js/191.9fd2f58a.js"><link rel="prefetch" href="/assets/js/192.1f3b6ca8.js"><link rel="prefetch" href="/assets/js/193.50aae911.js"><link rel="prefetch" href="/assets/js/194.e166c10d.js"><link rel="prefetch" href="/assets/js/195.1a1f9e4a.js"><link rel="prefetch" href="/assets/js/196.072c3ce0.js"><link rel="prefetch" href="/assets/js/197.36a569b3.js"><link rel="prefetch" href="/assets/js/198.ef935ad0.js"><link rel="prefetch" href="/assets/js/199.0614cb86.js"><link rel="prefetch" href="/assets/js/20.335cca54.js"><link rel="prefetch" href="/assets/js/200.e9583ef5.js"><link rel="prefetch" href="/assets/js/201.b4147cd7.js"><link rel="prefetch" href="/assets/js/202.655454f0.js"><link rel="prefetch" href="/assets/js/203.f00817d3.js"><link rel="prefetch" href="/assets/js/204.6f3bfde7.js"><link rel="prefetch" href="/assets/js/205.01353228.js"><link rel="prefetch" href="/assets/js/206.6d142fbd.js"><link rel="prefetch" href="/assets/js/207.f4f1071e.js"><link rel="prefetch" href="/assets/js/208.497a96dd.js"><link rel="prefetch" href="/assets/js/209.f813458b.js"><link rel="prefetch" href="/assets/js/21.8c3060b4.js"><link rel="prefetch" href="/assets/js/210.a45cff9c.js"><link rel="prefetch" href="/assets/js/211.5af25a9e.js"><link rel="prefetch" href="/assets/js/212.28908eba.js"><link rel="prefetch" href="/assets/js/213.93ca2d15.js"><link rel="prefetch" href="/assets/js/214.674059a0.js"><link rel="prefetch" href="/assets/js/215.d03b45be.js"><link rel="prefetch" href="/assets/js/216.64aebb7b.js"><link rel="prefetch" href="/assets/js/217.fd00686a.js"><link rel="prefetch" href="/assets/js/218.1bc04620.js"><link rel="prefetch" href="/assets/js/219.f93bf7a6.js"><link rel="prefetch" href="/assets/js/22.d30695a0.js"><link rel="prefetch" href="/assets/js/220.2a4ece08.js"><link rel="prefetch" href="/assets/js/221.42c08a34.js"><link rel="prefetch" href="/assets/js/222.598decbc.js"><link rel="prefetch" href="/assets/js/223.fb835c56.js"><link rel="prefetch" href="/assets/js/224.54855e83.js"><link rel="prefetch" href="/assets/js/225.3d94f453.js"><link rel="prefetch" href="/assets/js/226.2468bc8c.js"><link rel="prefetch" href="/assets/js/227.140240fe.js"><link rel="prefetch" href="/assets/js/228.eddc9919.js"><link rel="prefetch" href="/assets/js/229.7f4447ca.js"><link rel="prefetch" href="/assets/js/23.c21377c0.js"><link rel="prefetch" href="/assets/js/230.5f994ca9.js"><link rel="prefetch" href="/assets/js/231.2c87bfd0.js"><link rel="prefetch" href="/assets/js/232.491ed5e5.js"><link rel="prefetch" href="/assets/js/233.12245eff.js"><link rel="prefetch" href="/assets/js/234.da21e051.js"><link rel="prefetch" href="/assets/js/235.ad48abdb.js"><link rel="prefetch" href="/assets/js/236.3a295dec.js"><link rel="prefetch" href="/assets/js/237.84ff9c9b.js"><link rel="prefetch" href="/assets/js/238.627264aa.js"><link rel="prefetch" href="/assets/js/239.da37d07f.js"><link rel="prefetch" href="/assets/js/24.cc9cb1b0.js"><link rel="prefetch" href="/assets/js/240.f14cafaf.js"><link rel="prefetch" href="/assets/js/241.14ce6be3.js"><link rel="prefetch" href="/assets/js/242.9b6f988e.js"><link rel="prefetch" href="/assets/js/243.52a22828.js"><link rel="prefetch" href="/assets/js/244.41d248ca.js"><link rel="prefetch" href="/assets/js/245.1ba76fb4.js"><link rel="prefetch" href="/assets/js/246.cf8b4383.js"><link rel="prefetch" href="/assets/js/247.72a2b769.js"><link rel="prefetch" href="/assets/js/248.818a247a.js"><link rel="prefetch" href="/assets/js/249.095696b0.js"><link rel="prefetch" href="/assets/js/25.6b7591da.js"><link rel="prefetch" href="/assets/js/250.40e471ff.js"><link rel="prefetch" href="/assets/js/251.dd9c98c7.js"><link rel="prefetch" href="/assets/js/252.322c13d1.js"><link rel="prefetch" href="/assets/js/253.a74589e8.js"><link rel="prefetch" href="/assets/js/254.c0b11411.js"><link rel="prefetch" href="/assets/js/255.a31b5869.js"><link rel="prefetch" href="/assets/js/256.65a4a631.js"><link rel="prefetch" href="/assets/js/257.6c275bae.js"><link rel="prefetch" href="/assets/js/258.29edab81.js"><link rel="prefetch" href="/assets/js/259.a44df503.js"><link rel="prefetch" href="/assets/js/26.607efd21.js"><link rel="prefetch" href="/assets/js/260.e829b6db.js"><link rel="prefetch" href="/assets/js/261.b0af8f05.js"><link rel="prefetch" href="/assets/js/262.16e28745.js"><link rel="prefetch" href="/assets/js/263.bd55ccfb.js"><link rel="prefetch" href="/assets/js/264.542e2765.js"><link rel="prefetch" href="/assets/js/265.7fbdc730.js"><link rel="prefetch" href="/assets/js/266.d5354498.js"><link rel="prefetch" href="/assets/js/267.4fa2b728.js"><link rel="prefetch" href="/assets/js/268.d8050f72.js"><link rel="prefetch" href="/assets/js/269.860f97fb.js"><link rel="prefetch" href="/assets/js/27.9e25f953.js"><link rel="prefetch" href="/assets/js/270.d4607b7c.js"><link rel="prefetch" href="/assets/js/271.32e58adb.js"><link rel="prefetch" href="/assets/js/272.16c3fb95.js"><link rel="prefetch" href="/assets/js/273.c6b08152.js"><link rel="prefetch" href="/assets/js/274.ad95be0e.js"><link rel="prefetch" href="/assets/js/275.5f216f81.js"><link rel="prefetch" href="/assets/js/276.d92d5f9c.js"><link rel="prefetch" href="/assets/js/277.3c17ccd3.js"><link rel="prefetch" href="/assets/js/278.0c8cae32.js"><link rel="prefetch" href="/assets/js/279.dcd3c96d.js"><link rel="prefetch" href="/assets/js/28.de5fbffd.js"><link rel="prefetch" href="/assets/js/280.5bf9735e.js"><link rel="prefetch" href="/assets/js/281.ede2be97.js"><link rel="prefetch" href="/assets/js/282.39c15f23.js"><link rel="prefetch" href="/assets/js/283.e1c65b67.js"><link rel="prefetch" href="/assets/js/284.f3de51ff.js"><link rel="prefetch" href="/assets/js/285.07e0a191.js"><link rel="prefetch" href="/assets/js/286.d67567fb.js"><link rel="prefetch" href="/assets/js/287.b1ba4806.js"><link rel="prefetch" href="/assets/js/288.58158555.js"><link rel="prefetch" href="/assets/js/289.1070b060.js"><link rel="prefetch" href="/assets/js/29.a31435b1.js"><link rel="prefetch" href="/assets/js/290.4c4ff771.js"><link rel="prefetch" href="/assets/js/291.05d7dacb.js"><link rel="prefetch" href="/assets/js/292.c6b2ff86.js"><link rel="prefetch" href="/assets/js/293.dd9ac7d5.js"><link rel="prefetch" href="/assets/js/294.0ad93593.js"><link rel="prefetch" href="/assets/js/295.10a4d3cc.js"><link rel="prefetch" href="/assets/js/296.8dd679cd.js"><link rel="prefetch" href="/assets/js/297.958699f4.js"><link rel="prefetch" href="/assets/js/298.db46105e.js"><link rel="prefetch" href="/assets/js/299.98788b55.js"><link rel="prefetch" href="/assets/js/30.2a46f39a.js"><link rel="prefetch" href="/assets/js/300.7171d756.js"><link rel="prefetch" href="/assets/js/301.a327ccf9.js"><link rel="prefetch" href="/assets/js/302.eddbbf46.js"><link rel="prefetch" href="/assets/js/303.011a1812.js"><link rel="prefetch" href="/assets/js/304.b3d2809d.js"><link rel="prefetch" href="/assets/js/305.c7964909.js"><link rel="prefetch" href="/assets/js/306.1deec4af.js"><link rel="prefetch" href="/assets/js/307.99fa3519.js"><link rel="prefetch" href="/assets/js/308.71ea079a.js"><link rel="prefetch" href="/assets/js/309.cb8ba2cc.js"><link rel="prefetch" href="/assets/js/31.fab44020.js"><link rel="prefetch" href="/assets/js/310.0aa0c0b3.js"><link rel="prefetch" href="/assets/js/311.b4083583.js"><link rel="prefetch" href="/assets/js/312.f482271f.js"><link rel="prefetch" href="/assets/js/313.f9d39443.js"><link rel="prefetch" href="/assets/js/314.a2d1f5e3.js"><link rel="prefetch" href="/assets/js/315.3fb90439.js"><link rel="prefetch" href="/assets/js/316.c0f044f0.js"><link rel="prefetch" href="/assets/js/317.dddc1a4a.js"><link rel="prefetch" href="/assets/js/318.3254e19d.js"><link rel="prefetch" href="/assets/js/319.91dfc2a0.js"><link rel="prefetch" href="/assets/js/32.8f287f6a.js"><link rel="prefetch" href="/assets/js/320.106bf450.js"><link rel="prefetch" href="/assets/js/321.82f34bcd.js"><link rel="prefetch" href="/assets/js/322.eeef9dc9.js"><link rel="prefetch" href="/assets/js/323.c75babb0.js"><link rel="prefetch" href="/assets/js/324.d54a6492.js"><link rel="prefetch" href="/assets/js/325.76b7273b.js"><link rel="prefetch" href="/assets/js/326.4e8805ea.js"><link rel="prefetch" href="/assets/js/327.d62d13a8.js"><link rel="prefetch" href="/assets/js/328.3ca46a63.js"><link rel="prefetch" href="/assets/js/329.6a107c33.js"><link rel="prefetch" href="/assets/js/33.5af74851.js"><link rel="prefetch" href="/assets/js/330.b4d8ab0b.js"><link rel="prefetch" href="/assets/js/331.618f6def.js"><link rel="prefetch" href="/assets/js/332.3d4c9612.js"><link rel="prefetch" href="/assets/js/333.117e8020.js"><link rel="prefetch" href="/assets/js/334.2fe8d9b7.js"><link rel="prefetch" href="/assets/js/335.0c31be40.js"><link rel="prefetch" href="/assets/js/336.351485be.js"><link rel="prefetch" href="/assets/js/337.5a7bfc08.js"><link rel="prefetch" href="/assets/js/338.6c7d249f.js"><link rel="prefetch" href="/assets/js/339.682690f4.js"><link rel="prefetch" href="/assets/js/34.5dfe1291.js"><link rel="prefetch" href="/assets/js/340.b5cdb42e.js"><link rel="prefetch" href="/assets/js/341.fb27a06c.js"><link rel="prefetch" href="/assets/js/342.8e2f44ea.js"><link rel="prefetch" href="/assets/js/343.f7bec8a4.js"><link rel="prefetch" href="/assets/js/344.738defee.js"><link rel="prefetch" href="/assets/js/345.e716023b.js"><link rel="prefetch" href="/assets/js/346.0838d343.js"><link rel="prefetch" href="/assets/js/347.ea14c3a2.js"><link rel="prefetch" href="/assets/js/348.bf57b876.js"><link rel="prefetch" href="/assets/js/349.c51797f5.js"><link rel="prefetch" href="/assets/js/35.0a7b7db7.js"><link rel="prefetch" href="/assets/js/350.9f56c7ca.js"><link rel="prefetch" href="/assets/js/351.6b7a1c79.js"><link rel="prefetch" href="/assets/js/352.4cc5a7ff.js"><link rel="prefetch" href="/assets/js/353.76cd6b37.js"><link rel="prefetch" href="/assets/js/355.c5ffb190.js"><link rel="prefetch" href="/assets/js/356.29e3e2cd.js"><link rel="prefetch" href="/assets/js/357.359b4fdf.js"><link rel="prefetch" href="/assets/js/358.02bee4be.js"><link rel="prefetch" href="/assets/js/359.20c5d24f.js"><link rel="prefetch" href="/assets/js/36.8a8c44ca.js"><link rel="prefetch" href="/assets/js/360.42ffe98f.js"><link rel="prefetch" href="/assets/js/361.9aa30956.js"><link rel="prefetch" href="/assets/js/362.b3bfe78e.js"><link rel="prefetch" href="/assets/js/363.715dceba.js"><link rel="prefetch" href="/assets/js/364.1bf938a5.js"><link rel="prefetch" href="/assets/js/365.7712ed2c.js"><link rel="prefetch" href="/assets/js/366.3b48b0f0.js"><link rel="prefetch" href="/assets/js/367.e3bf3b9c.js"><link rel="prefetch" href="/assets/js/368.ee547bda.js"><link rel="prefetch" href="/assets/js/369.736a646d.js"><link rel="prefetch" href="/assets/js/37.7ed1a8d1.js"><link rel="prefetch" href="/assets/js/370.0cd94992.js"><link rel="prefetch" href="/assets/js/371.9c126e32.js"><link rel="prefetch" href="/assets/js/372.e0dae98b.js"><link rel="prefetch" href="/assets/js/373.3f497d20.js"><link rel="prefetch" href="/assets/js/374.8265b294.js"><link rel="prefetch" href="/assets/js/375.1691bf1a.js"><link rel="prefetch" href="/assets/js/376.d1bc249a.js"><link rel="prefetch" href="/assets/js/377.a70ed1ed.js"><link rel="prefetch" href="/assets/js/378.06ee3a0c.js"><link rel="prefetch" href="/assets/js/379.d482914b.js"><link rel="prefetch" href="/assets/js/38.8d2f9b02.js"><link rel="prefetch" href="/assets/js/380.772ce624.js"><link rel="prefetch" href="/assets/js/381.272a5a56.js"><link rel="prefetch" href="/assets/js/382.538e2883.js"><link rel="prefetch" href="/assets/js/383.27a09ab5.js"><link rel="prefetch" href="/assets/js/384.f6699047.js"><link rel="prefetch" href="/assets/js/385.1753768d.js"><link rel="prefetch" href="/assets/js/386.4a939926.js"><link rel="prefetch" href="/assets/js/387.b6fc5efc.js"><link rel="prefetch" href="/assets/js/388.39561bad.js"><link rel="prefetch" href="/assets/js/389.39d88d6c.js"><link rel="prefetch" href="/assets/js/39.977e55a2.js"><link rel="prefetch" href="/assets/js/390.257ba104.js"><link rel="prefetch" href="/assets/js/391.7fee02e7.js"><link rel="prefetch" href="/assets/js/392.d06b100d.js"><link rel="prefetch" href="/assets/js/393.9a381cee.js"><link rel="prefetch" href="/assets/js/394.ff541e95.js"><link rel="prefetch" href="/assets/js/395.1762634a.js"><link rel="prefetch" href="/assets/js/396.18935752.js"><link rel="prefetch" href="/assets/js/397.3b471025.js"><link rel="prefetch" href="/assets/js/398.c19c7de2.js"><link rel="prefetch" href="/assets/js/399.ff63d0ee.js"><link rel="prefetch" href="/assets/js/4.b5d5c8b1.js"><link rel="prefetch" href="/assets/js/40.6f6fb483.js"><link rel="prefetch" href="/assets/js/400.9512b32d.js"><link rel="prefetch" href="/assets/js/401.0dd750ee.js"><link rel="prefetch" href="/assets/js/402.89f4cfc1.js"><link rel="prefetch" href="/assets/js/403.03cab865.js"><link rel="prefetch" href="/assets/js/404.e149b178.js"><link rel="prefetch" href="/assets/js/405.5757c50b.js"><link rel="prefetch" href="/assets/js/406.275df76e.js"><link rel="prefetch" href="/assets/js/407.60ff3fd6.js"><link rel="prefetch" href="/assets/js/408.a3278547.js"><link rel="prefetch" href="/assets/js/409.82295bb0.js"><link rel="prefetch" href="/assets/js/41.f1dd1831.js"><link rel="prefetch" href="/assets/js/410.4908ddb7.js"><link rel="prefetch" href="/assets/js/411.a1668ba1.js"><link rel="prefetch" href="/assets/js/412.5f32829d.js"><link rel="prefetch" href="/assets/js/413.2073ec9e.js"><link rel="prefetch" href="/assets/js/414.3b925d0b.js"><link rel="prefetch" href="/assets/js/415.60574f9c.js"><link rel="prefetch" href="/assets/js/416.a4d5a572.js"><link rel="prefetch" href="/assets/js/417.a50f9fce.js"><link rel="prefetch" href="/assets/js/418.b7270715.js"><link rel="prefetch" href="/assets/js/419.0160b711.js"><link rel="prefetch" href="/assets/js/42.2678c675.js"><link rel="prefetch" href="/assets/js/420.eceb0610.js"><link rel="prefetch" href="/assets/js/421.6d223975.js"><link rel="prefetch" href="/assets/js/422.37d30681.js"><link rel="prefetch" href="/assets/js/423.cdde877a.js"><link rel="prefetch" href="/assets/js/424.e6b188c7.js"><link rel="prefetch" href="/assets/js/425.07916e69.js"><link rel="prefetch" href="/assets/js/426.fe282fd2.js"><link rel="prefetch" href="/assets/js/427.091fed79.js"><link rel="prefetch" href="/assets/js/428.018905f3.js"><link rel="prefetch" href="/assets/js/429.1d2ba504.js"><link rel="prefetch" href="/assets/js/43.5a7a89fd.js"><link rel="prefetch" href="/assets/js/430.0fdf8f0b.js"><link rel="prefetch" href="/assets/js/431.820d99bb.js"><link rel="prefetch" href="/assets/js/432.43e9cb10.js"><link rel="prefetch" href="/assets/js/433.ae737c26.js"><link rel="prefetch" href="/assets/js/434.d0cb3962.js"><link rel="prefetch" href="/assets/js/435.f2e9a9f9.js"><link rel="prefetch" href="/assets/js/436.443e4e28.js"><link rel="prefetch" href="/assets/js/437.9b7c6a47.js"><link rel="prefetch" href="/assets/js/438.18a4a09c.js"><link rel="prefetch" href="/assets/js/439.4758b8a3.js"><link rel="prefetch" href="/assets/js/44.a3a87e08.js"><link rel="prefetch" href="/assets/js/440.bdc71883.js"><link rel="prefetch" href="/assets/js/441.9a6fe71c.js"><link rel="prefetch" href="/assets/js/442.e535e9e8.js"><link rel="prefetch" href="/assets/js/443.f4faca82.js"><link rel="prefetch" href="/assets/js/444.b473988e.js"><link rel="prefetch" href="/assets/js/445.78ac5385.js"><link rel="prefetch" href="/assets/js/446.f28a3730.js"><link rel="prefetch" href="/assets/js/447.b750645d.js"><link rel="prefetch" href="/assets/js/448.56a3f163.js"><link rel="prefetch" href="/assets/js/449.25ea6c3f.js"><link rel="prefetch" href="/assets/js/45.20484792.js"><link rel="prefetch" href="/assets/js/450.2c33d110.js"><link rel="prefetch" href="/assets/js/451.d3686bb4.js"><link rel="prefetch" href="/assets/js/452.9b77f332.js"><link rel="prefetch" href="/assets/js/453.0e2b7abb.js"><link rel="prefetch" href="/assets/js/454.afd716c0.js"><link rel="prefetch" href="/assets/js/455.fa872f53.js"><link rel="prefetch" href="/assets/js/456.f98176ff.js"><link rel="prefetch" href="/assets/js/457.a3a79351.js"><link rel="prefetch" href="/assets/js/458.9c216200.js"><link rel="prefetch" href="/assets/js/459.b8a82b6b.js"><link rel="prefetch" href="/assets/js/46.0681e191.js"><link rel="prefetch" href="/assets/js/460.eac79b47.js"><link rel="prefetch" href="/assets/js/461.a67af417.js"><link rel="prefetch" href="/assets/js/462.64546845.js"><link rel="prefetch" href="/assets/js/463.3a6bb1ff.js"><link rel="prefetch" href="/assets/js/464.74201d93.js"><link rel="prefetch" href="/assets/js/465.d85e632a.js"><link rel="prefetch" href="/assets/js/466.4fc5a167.js"><link rel="prefetch" href="/assets/js/467.07d37400.js"><link rel="prefetch" href="/assets/js/468.96853156.js"><link rel="prefetch" href="/assets/js/469.a50ae16a.js"><link rel="prefetch" href="/assets/js/47.ee804674.js"><link rel="prefetch" href="/assets/js/470.6cf56bd5.js"><link rel="prefetch" href="/assets/js/471.59484050.js"><link rel="prefetch" href="/assets/js/472.ddf64aa7.js"><link rel="prefetch" href="/assets/js/473.95a896c2.js"><link rel="prefetch" href="/assets/js/474.d7ef72d1.js"><link rel="prefetch" href="/assets/js/475.a4c47cfb.js"><link rel="prefetch" href="/assets/js/476.22ee9a93.js"><link rel="prefetch" href="/assets/js/477.b3ba19f3.js"><link rel="prefetch" href="/assets/js/478.864bbf5c.js"><link rel="prefetch" href="/assets/js/479.4a7a598c.js"><link rel="prefetch" href="/assets/js/48.de09959f.js"><link rel="prefetch" href="/assets/js/480.ccc08278.js"><link rel="prefetch" href="/assets/js/481.8f44cbac.js"><link rel="prefetch" href="/assets/js/482.7409d304.js"><link rel="prefetch" href="/assets/js/483.2aa7b9f7.js"><link rel="prefetch" href="/assets/js/484.fba5806a.js"><link rel="prefetch" href="/assets/js/485.a4fab60f.js"><link rel="prefetch" href="/assets/js/486.194aeb49.js"><link rel="prefetch" href="/assets/js/487.3ae9d4dc.js"><link rel="prefetch" href="/assets/js/488.37514b2b.js"><link rel="prefetch" href="/assets/js/489.31acbbe7.js"><link rel="prefetch" href="/assets/js/49.4b0fe119.js"><link rel="prefetch" href="/assets/js/490.4f33761a.js"><link rel="prefetch" href="/assets/js/491.de9b8f18.js"><link rel="prefetch" href="/assets/js/492.a78d9437.js"><link rel="prefetch" href="/assets/js/493.0adb4a52.js"><link rel="prefetch" href="/assets/js/494.d458943e.js"><link rel="prefetch" href="/assets/js/495.c7d99c90.js"><link rel="prefetch" href="/assets/js/496.eee126ee.js"><link rel="prefetch" href="/assets/js/497.22135cf5.js"><link rel="prefetch" href="/assets/js/498.8c2002be.js"><link rel="prefetch" href="/assets/js/499.b727490e.js"><link rel="prefetch" href="/assets/js/5.5a730a22.js"><link rel="prefetch" href="/assets/js/50.bebd6a8f.js"><link rel="prefetch" href="/assets/js/500.ebb3e02b.js"><link rel="prefetch" href="/assets/js/501.2ec75ec2.js"><link rel="prefetch" href="/assets/js/502.999d21ae.js"><link rel="prefetch" href="/assets/js/503.3415452d.js"><link rel="prefetch" href="/assets/js/504.cc899380.js"><link rel="prefetch" href="/assets/js/505.c001019c.js"><link rel="prefetch" href="/assets/js/506.ee989b6a.js"><link rel="prefetch" href="/assets/js/507.4316a0d6.js"><link rel="prefetch" href="/assets/js/508.b4b6e06c.js"><link rel="prefetch" href="/assets/js/509.97911be7.js"><link rel="prefetch" href="/assets/js/51.268a7400.js"><link rel="prefetch" href="/assets/js/510.0b6fdfff.js"><link rel="prefetch" href="/assets/js/511.90321f3b.js"><link rel="prefetch" href="/assets/js/512.e385bb2f.js"><link rel="prefetch" href="/assets/js/513.cf5a70ba.js"><link rel="prefetch" href="/assets/js/514.39c6f992.js"><link rel="prefetch" href="/assets/js/515.28c955af.js"><link rel="prefetch" href="/assets/js/516.9c03d034.js"><link rel="prefetch" href="/assets/js/517.50fb0287.js"><link rel="prefetch" href="/assets/js/518.f1fae3ac.js"><link rel="prefetch" href="/assets/js/519.0cd16549.js"><link rel="prefetch" href="/assets/js/52.b3ba6c43.js"><link rel="prefetch" href="/assets/js/520.e76896cc.js"><link rel="prefetch" href="/assets/js/521.4a4cf9d6.js"><link rel="prefetch" href="/assets/js/522.d83c5f3d.js"><link rel="prefetch" href="/assets/js/523.e4a7ecef.js"><link rel="prefetch" href="/assets/js/524.36e761c2.js"><link rel="prefetch" href="/assets/js/525.6317ecc2.js"><link rel="prefetch" href="/assets/js/526.4c2caa69.js"><link rel="prefetch" href="/assets/js/527.57c5ab09.js"><link rel="prefetch" href="/assets/js/528.8bb25375.js"><link rel="prefetch" href="/assets/js/529.afecb950.js"><link rel="prefetch" href="/assets/js/53.fe2684d4.js"><link rel="prefetch" href="/assets/js/530.75117402.js"><link rel="prefetch" href="/assets/js/531.8f5561eb.js"><link rel="prefetch" href="/assets/js/532.eb990d2c.js"><link rel="prefetch" href="/assets/js/533.504e3919.js"><link rel="prefetch" href="/assets/js/534.ea4173a0.js"><link rel="prefetch" href="/assets/js/535.bd37f9ad.js"><link rel="prefetch" href="/assets/js/536.e2e7eb7a.js"><link rel="prefetch" href="/assets/js/537.6c0a0dcb.js"><link rel="prefetch" href="/assets/js/538.0ce6d97b.js"><link rel="prefetch" href="/assets/js/539.6a2cada2.js"><link rel="prefetch" href="/assets/js/54.abc729a1.js"><link rel="prefetch" href="/assets/js/540.89a5b6ff.js"><link rel="prefetch" href="/assets/js/541.9a2d47d4.js"><link rel="prefetch" href="/assets/js/542.aeb476e7.js"><link rel="prefetch" href="/assets/js/543.f6480bc9.js"><link rel="prefetch" href="/assets/js/544.87ded954.js"><link rel="prefetch" href="/assets/js/545.dca671b2.js"><link rel="prefetch" href="/assets/js/546.0eea9df9.js"><link rel="prefetch" href="/assets/js/547.58eca1e8.js"><link rel="prefetch" href="/assets/js/548.69640134.js"><link rel="prefetch" href="/assets/js/549.9e2f3a65.js"><link rel="prefetch" href="/assets/js/55.98f29d94.js"><link rel="prefetch" href="/assets/js/550.344c4ac6.js"><link rel="prefetch" href="/assets/js/551.3935c91c.js"><link rel="prefetch" href="/assets/js/552.2086fbe8.js"><link rel="prefetch" href="/assets/js/553.2aceadd3.js"><link rel="prefetch" href="/assets/js/554.1afd3108.js"><link rel="prefetch" href="/assets/js/555.16f1c7e8.js"><link rel="prefetch" href="/assets/js/556.2c9211d3.js"><link rel="prefetch" href="/assets/js/557.422b5e0d.js"><link rel="prefetch" href="/assets/js/558.1712976d.js"><link rel="prefetch" href="/assets/js/559.0052055f.js"><link rel="prefetch" href="/assets/js/56.fcf66dfb.js"><link rel="prefetch" href="/assets/js/560.e445bc77.js"><link rel="prefetch" href="/assets/js/561.cf50436f.js"><link rel="prefetch" href="/assets/js/562.e9d4e67d.js"><link rel="prefetch" href="/assets/js/563.15836f75.js"><link rel="prefetch" href="/assets/js/564.695e5d1f.js"><link rel="prefetch" href="/assets/js/565.e891cf80.js"><link rel="prefetch" href="/assets/js/566.1ef531d4.js"><link rel="prefetch" href="/assets/js/567.c04c597f.js"><link rel="prefetch" href="/assets/js/568.bbc2c743.js"><link rel="prefetch" href="/assets/js/569.7fca8ca1.js"><link rel="prefetch" href="/assets/js/57.a1d6e8e4.js"><link rel="prefetch" href="/assets/js/570.db8c6287.js"><link rel="prefetch" href="/assets/js/571.4321f994.js"><link rel="prefetch" href="/assets/js/572.8ab39750.js"><link rel="prefetch" href="/assets/js/573.e7b53730.js"><link rel="prefetch" href="/assets/js/574.637b580f.js"><link rel="prefetch" href="/assets/js/575.76b4f37b.js"><link rel="prefetch" href="/assets/js/576.f7e9268a.js"><link rel="prefetch" href="/assets/js/577.45296474.js"><link rel="prefetch" href="/assets/js/578.21525c52.js"><link rel="prefetch" href="/assets/js/579.0d0ccbb6.js"><link rel="prefetch" href="/assets/js/58.583ad48f.js"><link rel="prefetch" href="/assets/js/580.ae1d1ab5.js"><link rel="prefetch" href="/assets/js/581.f636f137.js"><link rel="prefetch" href="/assets/js/582.2feabe66.js"><link rel="prefetch" href="/assets/js/583.fb18929b.js"><link rel="prefetch" href="/assets/js/584.f79f539f.js"><link rel="prefetch" href="/assets/js/585.bf68105e.js"><link rel="prefetch" href="/assets/js/586.1d3cb142.js"><link rel="prefetch" href="/assets/js/587.f4bc14f0.js"><link rel="prefetch" href="/assets/js/588.e9be58d3.js"><link rel="prefetch" href="/assets/js/589.cf0068e8.js"><link rel="prefetch" href="/assets/js/59.609855d3.js"><link rel="prefetch" href="/assets/js/590.ac3b9f3f.js"><link rel="prefetch" href="/assets/js/591.61f4342c.js"><link rel="prefetch" href="/assets/js/592.c8b710ce.js"><link rel="prefetch" href="/assets/js/593.13bca0bd.js"><link rel="prefetch" href="/assets/js/594.49bc91f0.js"><link rel="prefetch" href="/assets/js/595.65755c43.js"><link rel="prefetch" href="/assets/js/596.85201e85.js"><link rel="prefetch" href="/assets/js/597.5968c2d2.js"><link rel="prefetch" href="/assets/js/598.cb10385e.js"><link rel="prefetch" href="/assets/js/599.329919fd.js"><link rel="prefetch" href="/assets/js/6.d05ff7d1.js"><link rel="prefetch" href="/assets/js/60.6192c5e6.js"><link rel="prefetch" href="/assets/js/600.6c4a484c.js"><link rel="prefetch" href="/assets/js/601.4461c2ae.js"><link rel="prefetch" href="/assets/js/602.a8d3fc33.js"><link rel="prefetch" href="/assets/js/603.ca2bb5fe.js"><link rel="prefetch" href="/assets/js/604.db803fb9.js"><link rel="prefetch" href="/assets/js/605.8ff2abfc.js"><link rel="prefetch" href="/assets/js/606.7113d146.js"><link rel="prefetch" href="/assets/js/607.f874afeb.js"><link rel="prefetch" href="/assets/js/608.69e0d555.js"><link rel="prefetch" href="/assets/js/609.e3e51762.js"><link rel="prefetch" href="/assets/js/61.11dbc940.js"><link rel="prefetch" href="/assets/js/610.48114a8b.js"><link rel="prefetch" href="/assets/js/611.20f5c8cd.js"><link rel="prefetch" href="/assets/js/612.49cf5c1f.js"><link rel="prefetch" href="/assets/js/613.c5d972ee.js"><link rel="prefetch" href="/assets/js/614.3712b906.js"><link rel="prefetch" href="/assets/js/615.0dfd0610.js"><link rel="prefetch" href="/assets/js/616.c60d74e0.js"><link rel="prefetch" href="/assets/js/617.05e47e1d.js"><link rel="prefetch" href="/assets/js/618.6f1c5ad5.js"><link rel="prefetch" href="/assets/js/619.6ab318a1.js"><link rel="prefetch" href="/assets/js/62.75354024.js"><link rel="prefetch" href="/assets/js/620.901c5159.js"><link rel="prefetch" href="/assets/js/621.add87549.js"><link rel="prefetch" href="/assets/js/622.408530c5.js"><link rel="prefetch" href="/assets/js/623.1aa20ea9.js"><link rel="prefetch" href="/assets/js/624.8616d341.js"><link rel="prefetch" href="/assets/js/625.7bdaa05f.js"><link rel="prefetch" href="/assets/js/626.6ca37760.js"><link rel="prefetch" href="/assets/js/627.1e67d181.js"><link rel="prefetch" href="/assets/js/628.69e16730.js"><link rel="prefetch" href="/assets/js/629.b7fbb50d.js"><link rel="prefetch" href="/assets/js/63.d3d8a2a7.js"><link rel="prefetch" href="/assets/js/630.a391b3de.js"><link rel="prefetch" href="/assets/js/631.f86fc53e.js"><link rel="prefetch" href="/assets/js/632.c1a60649.js"><link rel="prefetch" href="/assets/js/633.8ba0507c.js"><link rel="prefetch" href="/assets/js/634.549f3a14.js"><link rel="prefetch" href="/assets/js/635.c34e46b0.js"><link rel="prefetch" href="/assets/js/636.b9a9a30b.js"><link rel="prefetch" href="/assets/js/637.fac6e239.js"><link rel="prefetch" href="/assets/js/638.38c874bf.js"><link rel="prefetch" href="/assets/js/639.2cecf50a.js"><link rel="prefetch" href="/assets/js/64.fb01d06c.js"><link rel="prefetch" href="/assets/js/640.c9f97a1c.js"><link rel="prefetch" href="/assets/js/641.dc3dda81.js"><link rel="prefetch" href="/assets/js/642.b5923801.js"><link rel="prefetch" href="/assets/js/65.a5f22217.js"><link rel="prefetch" href="/assets/js/66.a48e0353.js"><link rel="prefetch" href="/assets/js/67.169d7837.js"><link rel="prefetch" href="/assets/js/68.27e92833.js"><link rel="prefetch" href="/assets/js/69.7643a0cf.js"><link rel="prefetch" href="/assets/js/7.63385f53.js"><link rel="prefetch" href="/assets/js/70.419bba25.js"><link rel="prefetch" href="/assets/js/71.ba04ac8a.js"><link rel="prefetch" href="/assets/js/72.6e7b692c.js"><link rel="prefetch" href="/assets/js/73.13285f8b.js"><link rel="prefetch" href="/assets/js/74.f87a5261.js"><link rel="prefetch" href="/assets/js/75.5e041d2a.js"><link rel="prefetch" href="/assets/js/76.f5339a14.js"><link rel="prefetch" href="/assets/js/77.d91c44df.js"><link rel="prefetch" href="/assets/js/78.29e9ac14.js"><link rel="prefetch" href="/assets/js/79.4b3118ff.js"><link rel="prefetch" href="/assets/js/8.901e16a3.js"><link rel="prefetch" href="/assets/js/80.8e295801.js"><link rel="prefetch" href="/assets/js/81.6d040b80.js"><link rel="prefetch" href="/assets/js/82.abf945e4.js"><link rel="prefetch" href="/assets/js/83.9bd95a69.js"><link rel="prefetch" href="/assets/js/84.bbc5db65.js"><link rel="prefetch" href="/assets/js/85.65463e7b.js"><link rel="prefetch" href="/assets/js/86.f64f6205.js"><link rel="prefetch" href="/assets/js/87.0260cfef.js"><link rel="prefetch" href="/assets/js/88.20d35720.js"><link rel="prefetch" href="/assets/js/89.87aaf95d.js"><link rel="prefetch" href="/assets/js/9.639ec32e.js"><link rel="prefetch" href="/assets/js/90.aca688c1.js"><link rel="prefetch" href="/assets/js/91.209eeece.js"><link rel="prefetch" href="/assets/js/92.6569647a.js"><link rel="prefetch" href="/assets/js/93.8b68023f.js"><link rel="prefetch" href="/assets/js/94.f32ead7e.js"><link rel="prefetch" href="/assets/js/95.953de281.js"><link rel="prefetch" href="/assets/js/96.3b33cb4c.js"><link rel="prefetch" href="/assets/js/97.f1ecb3a8.js"><link rel="prefetch" href="/assets/js/98.99874bfb.js"><link rel="prefetch" href="/assets/js/99.642326ea.js"><link rel="prefetch" href="/assets/js/vendors~docsearch.ac6383e3.js"> |
| <link rel="stylesheet" href="/assets/css/0.styles.f7fca28c.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/QuickStart/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.12.x/QuickStart/QuickStart.html" class="nav-link">V0.12.x</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/SeriesReader.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/SystemDesign/DataQuery/SeriesReader.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/QuickStart/QuickStart.html" class="nav-link">In progress</a></li><li class="dropdown-item"><!----> <a href="/zh/UserGuide/V0.12.x/QuickStart/QuickStart.html" class="nav-link">V0.12.x</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/SeriesReader.html" class="nav-link">English</a></li><li class="dropdown-item"><!----> <a href="/zh/SystemDesign/DataQuery/SeriesReader.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" aria-current="page" class="active 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" class="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="查询基础组件"><a href="#查询基础组件" class="header-anchor">#</a> 查询基础组件</h1> <h2 id="设计原理"><a href="#设计原理" class="header-anchor">#</a> 设计原理</h2> <p>IoTDB server 模块共提供 3 种不同形式的针对单个时间序列的读取接口，以支持不同形式的查询。</p> <ul><li>原始数据查询接口，返回 BatchData，可带时间过滤条件或值过滤条件，两种过滤不可同时存在。</li> <li>聚合查询接口 （主要用于聚合查询和降采样查询）</li> <li>按递增时间戳查询对应值的接口（主要用于带值过滤的查询）</li></ul> <h2 id="相关接口"><a href="#相关接口" class="header-anchor">#</a> 相关接口</h2> <p>以上三种读取单个时间序列数据的方式对应代码里的三个接口</p> <h3 id="org-apache-iotdb-tsfile-read-reader-ibatchreader"><a href="#org-apache-iotdb-tsfile-read-reader-ibatchreader" class="header-anchor">#</a> org.apache.iotdb.tsfile.read.reader.IBatchReader</h3> <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>// 判断是否还有 BatchData |
| boolean hasNextBatch() throws IOException; |
| |
| // 获得下一个 BatchData，并把游标后移 |
| BatchData nextBatch() throws IOException; |
| </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></div></div><h4 id="使用流程"><a href="#使用流程" class="header-anchor">#</a> 使用流程</h4> <div class="language- line-numbers-mode"><pre class="language-text"><code>while (batchReader.hasNextBatch()) { |
| BatchData batchData = batchReader.nextBatch(); |
| |
| // use batchData to do some work |
| ... |
| } |
| </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></div></div><h3 id="org-apache-iotdb-db-query-reader-series-iaggregatereader"><a href="#org-apache-iotdb-db-query-reader-series-iaggregatereader" class="header-anchor">#</a> org.apache.iotdb.db.query.reader.series.IAggregateReader</h3> <h4 id="主要方法-2"><a href="#主要方法-2" class="header-anchor">#</a> 主要方法</h4> <div class="language- line-numbers-mode"><pre class="language-text"><code>// 判断是否还有 Chunk |
| boolean hasNextChunk() throws IOException; |
| |
| // 判断是否能够使用当前 Chunk 的统计信息 |
| boolean canUseCurrentChunkStatistics(); |
| |
| // 获得当前 Chunk 的统计信息 |
| Statistics currentChunkStatistics(); |
| |
| // 跳过当前 Chunk |
| void skipCurrentChunk(); |
| |
| // 判断当前Chunk是否还有下一个 Page |
| boolean hasNextPage() throws IOException; |
| |
| // 判断能否使用当前 Page 的统计信息 |
| boolean canUseCurrentPageStatistics() throws IOException; |
| |
| // 获得当前 Page 的统计信息 |
| Statistics currentPageStatistics() throws IOException; |
| |
| // 跳过当前的 Page |
| void skipCurrentPage(); |
| |
| // 获得当前 Page 的数据 |
| BatchData nextPage() throws IOException; |
| </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><h4 id="一般使用流程"><a href="#一般使用流程" class="header-anchor">#</a> 一般使用流程</h4> <div class="language- line-numbers-mode"><pre class="language-text"><code>while (aggregateReader.hasNextChunk()) { |
| if (aggregateReader.canUseCurrentChunkStatistics()) { |
| Statistics chunkStatistics = aggregateReader.currentChunkStatistics(); |
| |
| // 用 chunk 层的统计信息计算 |
| ... |
| |
| aggregateReader.skipCurrentChunk(); |
| continue; |
| } |
| |
| // 把当前 chunk 中的 page 消耗完 |
| while (aggregateReader.hasNextPage()) { |
| if (aggregateReader.canUseCurrentPageStatistics()) { |
| // 可以用统计信息 |
| Statistics pageStatistic = aggregateReader.currentPageStatistics(); |
| |
| // 用 page 层的统计信息计算 |
| ... |
| |
| aggregateReader.skipCurrentPage(); |
| continue; |
| } else { |
| // 不能用统计信息，需要用数据计算 |
| BatchData batchData = aggregateReader.nextOverlappedPage(); |
| |
| // 用 batchData 计算 |
| ... |
| } |
| } |
| } |
| </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><span class="line-number">31</span><br></div></div><h3 id="org-apache-iotdb-db-query-reader-ireaderbytimestamp"><a href="#org-apache-iotdb-db-query-reader-ireaderbytimestamp" class="header-anchor">#</a> org.apache.iotdb.db.query.reader.IReaderByTimestamp</h3> <h4 id="主要方法-3"><a href="#主要方法-3" class="header-anchor">#</a> 主要方法</h4> <div class="language- line-numbers-mode"><pre class="language-text"><code>// 得到给定时间戳的值，如果不存在返回 null（要求传入的 timestamp 是递增的） |
| Object getValueInTimestamp(long timestamp) throws IOException; |
| |
| // 给定一批递增时间戳的值，返回一批结果（减少方法调用次数） |
| Object[] getValuesInTimestamps(long[] timestamps) throws IOException; |
| </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></div></div><h4 id="一般使用流程-2"><a href="#一般使用流程-2" class="header-anchor">#</a> 一般使用流程</h4> <p>该接口在带值过滤的查询中被使用，TimeGenerator生成时间戳后，使用该接口获得该时间戳对应的value</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>Object value = readerByTimestamp.getValueInTimestamp(timestamp); |
| |
| or |
| |
| Object[] values = readerByTimestamp.getValueInTimestamp(timestamps); |
| </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></div></div><h2 id="具体实现类"><a href="#具体实现类" class="header-anchor">#</a> 具体实现类</h2> <p>上述三个接口都有其对应的实现类，由于以上三种查询有共性，我们设计了一个基础的 SeriesReader 工具类，封装了对于一个时间序列读取操作的基本方法，帮助实现以上三种接口。下面首先介绍 SeriesReader 的设计原理，然后再依次介绍三个接口的具体实现。</p> <h3 id="org-apache-iotdb-db-query-reader-series-seriesreader"><a href="#org-apache-iotdb-db-query-reader-series-seriesreader" class="header-anchor">#</a> org.apache.iotdb.db.query.reader.series.SeriesReader</h3> <h4 id="设计思想"><a href="#设计思想" class="header-anchor">#</a> 设计思想</h4> <p>背景知识：TsFile 文件（TsFileResource）解开后可以得到 ChunkMetadata，ChunkMetadata 解开后可以得到一堆 PageReader，PageReader 可以直接返回 BatchData 数据点。</p> <p>为了支持以上三种接口</p> <p>数据按照粒度从大到小分成四种：文件，Chunk，Page，相交数据点。在原始数据查询中，最大的数据块返回粒度是一个 page，如果一个 page 和其他 page 由于乱序写入相互覆盖了，就解开成数据点做合并。聚合查询中优先使用 Chunk 的统计信息，其次是 Page 的统计信息，最后是相交数据点。</p> <p>设计原则是能用粒度大的就不用粒度小的。</p> <p>首先介绍一下SeriesReader里的几个重要字段</p> <div class="language- line-numbers-mode"><pre class="language-text"><code> |
| /* |
| * 文件层 |
| */ |
| private final List<TsFileResource> seqFileResource; |
| 顺序文件列表，因为顺序文件本身就保证有序，且时间戳互不重叠，只需使用List进行存储 |
| |
| private final PriorityQueue<TsFileResource> unseqFileResource; |
| 乱序文件列表，因为乱序文件互相之间不保证顺序性，且可能有重叠，为了保证顺序，使用优先队列进行存储 |
| |
| /* |
| * chunk 层 |
| * |
| * 三个字段之间数据永远不重复，first 永远是第一个（开始时间最小） |
| */ |
| private ChunkMetaData firstChunkMetaData; |
| 填充 chunk 层时优先填充此字段，保证这个 chunk 具有当前最小开始时间 |
| |
| private final List<ChunkMetaData> seqChunkMetadatas; |
| 顺序文件解开后得到的 ChunkMetaData 存放在此，本身有序且互不重叠，所以使用 List 存储 |
| |
| private final PriorityQueue<ChunkMetaData> unseqChunkMetadatas; |
| 乱序文件解开后得到的 ChunkMetaData 存放在此，互相之间可能有重叠，为了保证顺序，使用优先队列进行存储 |
| |
| /* |
| * page 层 |
| * |
| * 两个字段之间数据永远不重复，first 永远是第一个（开始时间最小） |
| */ |
| private VersionPageReader firstPageReader; |
| 开始时间最小的 page reader |
| |
| private PriorityQueue<VersionPageReader> cachedPageReaders; |
| 当前获得的所有 page reader，按照每个 page 的起始时间进行排序 |
| |
| /* |
| * 相交数据点层 |
| */ |
| private PriorityMergeReader mergeReader; |
| 本质上是多个带优先级的 page，按时间戳从低到高输出数据点，时间戳相同时，保留优先级高的 |
| |
| /* |
| * 相交数据点产出结果的缓存 |
| */ |
| private boolean hasCachedNextOverlappedPage; |
| 是否缓存了下一个batch |
| |
| private BatchData cachedBatchData; |
| 缓存的下一个batch的引用 |
| </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><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br><span class="line-number">36</span><br><span class="line-number">37</span><br><span class="line-number">38</span><br><span class="line-number">39</span><br><span class="line-number">40</span><br><span class="line-number">41</span><br><span class="line-number">42</span><br><span class="line-number">43</span><br><span class="line-number">44</span><br><span class="line-number">45</span><br><span class="line-number">46</span><br><span class="line-number">47</span><br><span class="line-number">48</span><br><span class="line-number">49</span><br></div></div><p>下面介绍一下SeriesReader里的重要方法</p> <h4 id="hasnextchunk"><a href="#hasnextchunk" class="header-anchor">#</a> hasNextChunk()</h4> <ul><li><p>主要功能：判断该时间序列还有没有下一个chunk。</p></li> <li><p>约束：在调用这个方法前，需要保证 <code>SeriesReader</code> 内已经没有 page 和 数据点 层级的数据了，也就是之前解开的 chunk 都消耗完了。</p></li> <li><p>实现：如果 <code>firstChunkMetaData</code> 不为空，则代表当前已经缓存了第一个 <code>ChunkMetaData</code>，且未被使用，直接返回<code>true</code>；</p> <p>尝试去解开第一个顺序文件和第一个乱序文件，填充 chunk 层。并解开与 <code>firstChunkMetadata</code> 相重合的所有文件。</p></li></ul> <h4 id="ischunkoverlapped"><a href="#ischunkoverlapped" class="header-anchor">#</a> isChunkOverlapped()</h4> <ul><li><p>主要功能：判断当前的 chunk 有没有与其他 Chunk 有重叠</p></li> <li><p>约束：在调用这个方法前，需要保证 chunk 层已经缓存了 <code>firstChunkMetadata</code>，也就是调用了 hasNextChunk() 并且为 true。</p></li> <li><p>实现：直接把 <code>firstChunkMetadata</code> 与 <code>seqChunkMetadatas</code> 和 <code>unseqChunkMetadatas</code> 相比较。因为此前已经保证所有和 <code>firstChunkMetadata</code> 相交的文件都被解开了。</p></li></ul> <h4 id="currentchunkstatistics"><a href="#currentchunkstatistics" class="header-anchor">#</a> currentChunkStatistics()</h4> <p>返回 <code>firstChunkMetaData</code> 的统计信息。</p> <h4 id="skipcurrentchunk"><a href="#skipcurrentchunk" class="header-anchor">#</a> skipCurrentChunk()</h4> <p>跳过当前 chunk。只需要将<code>firstChunkMetaData</code>置为<code>null</code>。</p> <h4 id="hasnextpage"><a href="#hasnextpage" class="header-anchor">#</a> hasNextPage()</h4> <ul><li><p>主要功能：判断 SeriesReader 中还有没有已经解开的 page，如果有相交的 page，就构造 <code>cachedBatchData</code> 并缓存，否则缓存 <code>firstPageReader</code>。</p></li> <li><p>实现：如果已经缓存了 <code>cachedBatchData</code> 就直接返回。如果有相交数据点，就构造 <code>cachedBatchData</code>。如果已经缓存了 <code>firstPageReader</code>，就直接返回。</p> <p>如果当前的 <code>firstChunkMetadata</code> 还没有解开，就解开与之重叠的所有 ChunkMetadata，构造 firstPageReader。</p> <p>判断，如果 <code>firstPageReader</code> 和 <code>cachedPageReaders</code> 相交，则构造 <code>cachedBatchData</code>，否则直接返回。</p></li></ul> <h4 id="ispageoverlapped"><a href="#ispageoverlapped" class="header-anchor">#</a> isPageOverlapped()</h4> <ul><li><p>主要功能：判断当前的 page 有没有与其他 page 有重叠</p></li> <li><p>约束：在调用这个方法前，需要保证调用了 hasNextPage() 并且为 true。也就是，有可能缓存了一个相交的 <code>cachedBatchData</code>，或者缓存了不相交的 <code>firstPageReader</code>。</p></li> <li><p>实现：先判断有没有 <code>cachedBatchData</code>，如果没有，就说明当前 page 不相交，则 <code>mergeReader</code> 里没数据。再判断 <code>firstPageReader</code> 是否与 <code>cachedPageReaders</code> 中的 page 相交。</p></li></ul> <h4 id="currentpagestatistics"><a href="#currentpagestatistics" class="header-anchor">#</a> currentPageStatistics()</h4> <p>返回 <code>firstPageReader</code> 的统计信息。</p> <h4 id="skipcurrentpage"><a href="#skipcurrentpage" class="header-anchor">#</a> skipCurrentPage()</h4> <p>跳过当前Page。只需要将 <code>firstPageReader</code> 置为 null。</p> <h4 id="nextpage"><a href="#nextpage" class="header-anchor">#</a> nextPage()</h4> <ul><li><p>主要功能：返回下一个相交或不相交的 page</p></li> <li><p>约束：在调用这个方法前，需要保证调用了 hasNextPage() 并且为 true。也就是，有可能缓存了一个相交的 <code>cachedBatchData</code>，或者缓存了不相交的 <code>firstPageReader</code>。</p></li> <li><p>实现：如果 <code>hasCachedNextOverlappedPage</code> 为 true，说明缓存了一个相交的 page，直接返回 <code>cachedBatchData</code>。否则当前 page 不相交，直接从 firstPageReader 里拿当前 page 的数据。</p></li></ul> <h4 id="hasnextoverlappedpage"><a href="#hasnextoverlappedpage" class="header-anchor">#</a> hasNextOverlappedPage()</h4> <ul><li><p>主要功能：内部方法，用来判断当前有没有重叠的数据，并且构造相交的 page 并缓存。</p></li> <li><p>实现：如果 <code>hasCachedNextOverlappedPage</code> 为 <code>true</code>，直接返回 <code>true</code>。</p> <p>否则，先调用 <code>tryToPutAllDirectlyOverlappedPageReadersIntoMergeReader()</code> 方法，将 <code>cachedPageReaders</code> 中所有与 <code>firstPageReader</code> 有重叠的放进 <code>mergeReader</code> 里。<code>mergeReader</code> 里维护了一个 <code>currentLargestEndTime</code> 变量，每次添加进新的 Reader 时被更新，用以记录当前添加进 <code>mergeReader</code> 的 page 的最大结束时间。 |
| 然后先从<code>mergeReader</code>里取出当前最大的结束时间，作为第一批数据的结束时间，记为<code>currentPageEndTime</code>。接着去遍历<code>mergeReader</code>，直到当前的时间戳大于<code>currentPageEndTime</code>。</p> <p>每从 mergeReader 移出一个点前，我们先要判断是否有与当前时间戳重叠的file或者chunk或者page（这里之所以还要再做一次判断，是因为，比如当前page是1-30，和他直接相交的page是20-50，还有一个page是40-60，每取一个点判断一次是想把40-60解开），如果有，解开相应的file或者chunk或者page，并将其放入<code>mergeReader</code>。完成重叠的判断后，从<code>mergeReader</code>中取出相应数据。</p> <p>完成迭代后将获得数据缓存在 <code>cachedBatchData</code> 中，并将 <code>hasCachedNextOverlappedPage</code> 置为 <code>true</code>。</p></li></ul> <h4 id="nextoverlappedpage"><a href="#nextoverlappedpage" class="header-anchor">#</a> nextOverlappedPage()</h4> <p>将缓存的<code>cachedBatchData</code>返回，并将<code>hasCachedNextOverlappedPage</code>置为<code>false</code>。</p> <h3 id="org-apache-iotdb-db-query-reader-series-seriesrawdatabatchreader"><a href="#org-apache-iotdb-db-query-reader-series-seriesrawdatabatchreader" class="header-anchor">#</a> org.apache.iotdb.db.query.reader.series.SeriesRawDataBatchReader</h3> <p><code>SeriesRawDataBatchReader</code>实现了<code>IBatchReader</code>。</p> <p>其方法<code>hasNextBatch()</code>的核心判断流程是</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>// 有缓存了 batch，直接返回 |
| if (hasCachedBatchData) { |
| return true; |
| } |
| |
| /* |
| * 如果 SeriesReader 里还有 page，返回 page |
| */ |
| if (readPageData()) { |
| hasCachedBatchData = true; |
| return true; |
| } |
| |
| /* |
| * 如果有 chunk，并且有 page，返回 page |
| */ |
| while (seriesReader.hasNextChunk()) { |
| if (readPageData()) { |
| hasCachedBatchData = true; |
| return true; |
| } |
| } |
| return hasCachedBatchData; |
| </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></div></div><h3 id="org-apache-iotdb-db-query-reader-series-seriesreaderbytimestamp"><a href="#org-apache-iotdb-db-query-reader-series-seriesreaderbytimestamp" class="header-anchor">#</a> org.apache.iotdb.db.query.reader.series.SeriesReaderByTimestamp</h3> <p><code>SeriesReaderByTimestamp</code> 实现了 <code>IReaderByTimestamp</code>。</p> <p>设计思想：当给一个时间戳要查询值时，这个时间戳可以转化为一个 time >= x 的过滤条件。不断更新这个过滤条件，并且跳过不满足的文件，chunk 和 page。</p> <p>实现方式：</p> <div class="language- line-numbers-mode"><pre class="language-text"><code>/* |
| * 优先判断下一个 page 有没有当前所查时间，能跳过就跳过 |
| */ |
| if (readPageData(timestamp)) { |
| return true; |
| } |
| |
| /* |
| * 判断下一个 chunk 有没有当前所查时间，能跳过就跳过 |
| */ |
| while (seriesReader.hasNextChunk()) { |
| Statistics statistics = seriesReader.currentChunkStatistics(); |
| if (!satisfyTimeFilter(statistics)) { |
| seriesReader.skipCurrentChunk(); |
| continue; |
| } |
| /* |
| * chunk 不能跳过，继续到 chunk 里检查 page |
| */ |
| if (readPageData(timestamp)) { |
| return true; |
| } |
| } |
| 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><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><h3 id="org-apache-iotdb-db-query-reader-series-seriesaggregatereader"><a href="#org-apache-iotdb-db-query-reader-series-seriesaggregatereader" class="header-anchor">#</a> org.apache.iotdb.db.query.reader.series.SeriesAggregateReader</h3> <p><code>SeriesAggregateReader</code> 实现了 <code>IAggregateReader</code></p> <p><code>IAggregateReader</code>的大部分接口方法都在<code>SeriesReader</code>有对应实现，除了<code>canUseCurrentChunkStatistics()</code>和<code>canUseCurrentPageStatistics()</code>两个方法。</p> <h4 id="canusecurrentchunkstatistics"><a href="#canusecurrentchunkstatistics" class="header-anchor">#</a> canUseCurrentChunkStatistics()</h4> <p>设计思想：可以用统计信息的条件是当前 chunk 不重叠，并且满足过滤条件。</p> <p>先调用<code>SeriesReader</code>的<code>currentChunkStatistics()</code>方法，获得当前chunk的统计信息，再调用<code>SeriesReader</code>的<code>isChunkOverlapped()</code>方法判断当前chunk是否重叠，如果当前chunk不重叠，且其统计信息满足过滤条件，则返回<code>true</code>，否则返回<code>false</code>。</p> <h4 id="canusecurrentpagestatistics"><a href="#canusecurrentpagestatistics" class="header-anchor">#</a> canUseCurrentPageStatistics()</h4> <p>设计思想：可以用统计信息的条件是当前 page 不重叠，并且满足过滤条件。</p> <p>先调用<code>SeriesReader</code>的 <code>currentPageStatistics()</code> 方法，获得当前page的统计信息，再调用<code>SeriesReader</code> 的 <code>isPageOverlapped()</code> 方法判断当前 page 是否重叠，如果当前page不重叠，且其统计信息满足过滤条件，则返回<code>true</code>，否则返回<code>false</code>。</p></div> <div class="page-nav"><p class="inner"><span class="prev"> |
| ← |
| <a href="/zh/SystemDesign/DataQuery/QueryFundamentals.html" class="prev"> |
| 查询基础介绍 |
| </a></span> <span class="next"><a href="/zh/SystemDesign/DataQuery/RawDataQuery.html"> |
| 原始数据查询 |
| </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.13a2c569.js" defer></script><script src="/assets/js/3.7fccac46.js" defer></script><script src="/assets/js/354.d811ac0e.js" defer></script> |
| </body> |
| </html> |
