如何使用Spark对象获取Hive表的位置值? [英] How to get the value of the location for a Hive table using a Spark object?

问题描述

我对能够获取给定Spark对象(SparkSession)的Hive表的 location 值感兴趣.获取此值的一种方法是通过以下SQL查询来解析位置的输出:

I am interested in being able to retrieve the location value of a Hive table given a Spark object (SparkSession). One way to obtain this value is by parsing the output of the location via the following SQL query:

describe formatted <table name>

我想知道是否存在另一种无需解析输出即可获取 location 值的方法.如果以上命令的输出在Hive版本之间发生更改，则API会非常有用.如果需要外部依赖，那会是什么?是否有一些示例火花代码可以获取位置值?

I was wondering if there is another way to obtain the location value without having to parse the output. An API would be great in case the output of the above command changes between Hive versions. If an external dependency is needed, which would it be? Is there some sample spark code that can obtain the location value?

推荐答案

第一种方法

您可以将input_file_name用于数据框.

它将为您提供零件文件的绝对文件路径.

it will give you absolute file-path for a part file.

spark.read.table("zen.intent_master").select(input_file_name).take(1)

然后从中提取表路径.

第二种方法

您可以说更多关于黑客的信息.

Its more of hack you can say.

package org.apache.spark.sql.hive

import java.net.URI

import org.apache.spark.sql.catalyst.catalog.{InMemoryCatalog, SessionCatalog}
import org.apache.spark.sql.catalyst.parser.ParserInterface
import org.apache.spark.sql.internal.{SessionState, SharedState}
import org.apache.spark.sql.SparkSession

class TableDetail {
  def getTableLocation(table: String, spark: SparkSession): URI = {
    val sessionState: SessionState = spark.sessionState
    val sharedState: SharedState = spark.sharedState
    val catalog: SessionCatalog = sessionState.catalog
    val sqlParser: ParserInterface = sessionState.sqlParser
    val client = sharedState.externalCatalog match {
      case catalog: HiveExternalCatalog => catalog.client
      case _: InMemoryCatalog => throw new IllegalArgumentException("In Memory catalog doesn't " +
        "support hive client API")
    }

    val idtfr = sqlParser.parseTableIdentifier(table)

    require(catalog.tableExists(idtfr), new IllegalArgumentException(idtfr + " done not exists"))
    val rawTable = client.getTable(idtfr.database.getOrElse("default"), idtfr.table)
    rawTable.location
  }
}

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