(window.webpackJsonp=window.webpackJsonp||[]).push([[29],{598:function(t,e,r){"use strict";r.r(e);var a=r(71),s=Object(a.a)({},(function(){var t=this,e=t.$createElement,r=t._self._c||e;return r("ContentSlotsDistributor",{attrs:{"slot-key":t.$parent.slotKey}},[r("h1",{attrs:{id:"spark-tsfile-connector"}},[r("a",{staticClass:"header-anchor",attrs:{href:"#spark-tsfile-connector"}},[t._v("#")]),t._v(" Spark Tsfile connector")]),t._v(" "),r("h2",{attrs:{id:"aim-of-design"}},[r("a",{staticClass:"header-anchor",attrs:{href:"#aim-of-design"}},[t._v("#")]),t._v(" aim of design")]),t._v(" "),r("ul",[r("li",[r("p",[t._v("Use Spark SQL to read the data of the specified Tsfile and return it to the client in the form of a Spark DataFrame")])]),t._v(" "),r("li",[r("p",[t._v("Generate Tsfile with data from Spark Dataframe")])])]),t._v(" "),r("h2",{attrs:{id:"supported-formats"}},[r("a",{staticClass:"header-anchor",attrs:{href:"#supported-formats"}},[t._v("#")]),t._v(" Supported formats")]),t._v(" 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Table structure inference and generation")]),t._v(" "),r("p",[t._v("This step is to make the table structure of the DataFrame match the table structure of the Tsfile to be queried.\nThe main logic is inferSchema function in src / main / scala / org / apache / iotdb / spark / tsfile / DefaultSource.scala")]),t._v(" "),r("h4",{attrs:{id:"_2-sql-parsing"}},[r("a",{staticClass:"header-anchor",attrs:{href:"#_2-sql-parsing"}},[t._v("#")]),t._v(" 2. SQL parsing")]),t._v(" "),r("p",[t._v("The purpose of this step is to transform user SQL statements into Tsfile native query expressions.")]),t._v(" "),r("p",[t._v("The main logic is the buildReader function in src / main / scala / org / apache / iotdb / spark / tsfile / DefaultSource.scala. SQL parsing wide table structure and narrow table structure")]),t._v(" "),r("h4",{attrs:{id:"_3-wide-table-structure"}},[r("a",{staticClass:"header-anchor",attrs:{href:"#_3-wide-table-structure"}},[t._v("#")]),t._v(" 3. 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