spark.sql.hive.caseSensitiveInferenceMode INFER_AND_SAVE Sets the action to take when a case-sensitive schema cannot be read from a Hive table’s properties. Although Spark SQL itself is not case-sensitive, Hive compatible file formats such as Parquet are. Spark SQL must use a case-preserving...
import java.util.Properties import org.apache.spark.sql.types._ import org.apache.spark.sql.{SparkSession, Row} import org.apache.spark object TestMySQL { def main(args: Array[String]) { val spark = SparkSession.builder() .appName("TestMySQL") .config("spark.master", "local")...
importorg.apache.spark.sql.SparkSessionvalspark=SparkSession.builder.appName("Create DataFrame").getOrCreate()valdf=spark.read.json("path/to/json/file") df.show() 通过编程方式创建。例如,使用createDataFrame方法: importorg.apache.spark.sql.{Row, SparkSession}importorg.apache.spark.sql.types.{Int...
withFilename public SparkConfigProperties withFilename(String filename) 设置filename 属性:spark config 属性文件的文件名。 Parameters: filename - 要设置的文件名值。 Returns: SparkConfigProperties 对象本身。适用于 Azure SDK for Java Preview在GitHub 上与我们协作 可以在 GitHub 上找到此内容的源,还...
public Object schemaTypePropertiesSchema() Get the schema property: The schema name of the Spark. Type: string (or Expression with resultType string). Returns: the schema value.table public Object table() Get the table property: The table name of the Spark. Type: string (or Expression with ...
spark.sql.hive.convertMetastoreParquet默认设置是true, 它代表使用spark-sql内置的parquet的reader和writer(即进行反序列化和序列化),它具有更好地性能,如果设置为false,则代表使用 Hive的序列化方式。 但是有时候当其设置为true时,会出现使用hive查询表有数据,而使用spark查询为空的情况. ...
ALTERTABLEtable_name CHANGE[COLUMN]col_old_name col_new_name column_type[COMMENTcol_comment][FIRST|AFTERcolumn_name] 现象描述:表是分区ORC表,Spark版本2.4x。 修改历史有历史分区数据的表的字段名后,导致spark-sql读取hive表历史分区时,被修改的字段FLN90读取到的都是null值。但是读取新的分区数据时,不受...
1. sparkSession.catalog.refreshTable(s"${dbName.tableName}") 2. sparkSession.catalog.refreshByPath(s"${path}") 1. 2. 3. 最后说一下最近后台小伙伴在生产中遇到的一个问题,大家如果在业务处理中遇到类似的问题,提供一个思路。 在说问题之前首先了解一个参数spark.sql.parquet.writeLegacyFormat(默认fal...
-- This CREATE TABLE works CREATE TABLE test (`a``b` int); 4 changes: 2 additions & 2 deletions 4 sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/ParseDriver.scala Original file line numberDiff line numberDiff line change @@ -289,8 +289,8 @@ class ParseException(...
Original file line numberDiff line numberDiff line change @@ -796,11 +796,11 @@ object SQLConf { .doc("Sets the compression codec used when writing ORC files. If either `compression` or " + "`orc.compress` is specified in the table-specific options/properties, the precedence " + "wou...