Create tables on JSON datasets

In this article we cover how to create a table on JSON datasets using SerDe. Download the JSON SerDe JAR Open the hive-json-serde 1.3.8 download page. Click on json-serde-1.3.8-jar-with-dependencies.jar to download the file json-serde-1.3.8-jar-with-dependencies.jar. Info You can review the Hive-JSON-Serde GitHub repo for more information on the JAR...

Optimize read performance from JDBC data sources

Problem Reading data from an external JDBC database is slow. How can I improve read performance? Solution See the detailed discussion in the Databricks documentation on how to optimize performance when reading data (AWS | Azure | GCP) from an external JDBC database....

Failure to detect encoding in JSON

Problem Spark job fails with an exception containing the message: Invalid UTF-32 character 0x1414141(above 10ffff)  at char #1, byte #7) At org.apache.spark.sql.catalyst.json.JacksonParser.parse Cause The JSON data source reader is able to automatically detect encoding of input JSON files using BOM at the beginning of the files. However, BOM is not ...

Inconsistent timestamp results with JDBC applications

Problem When using JDBC applications with Databricks clusters you see inconsistent java.sql.Timestamp results when switching between standard time and daylight saving time. Cause Databricks clusters use UTC by default. java.sql.Timestamp uses the JVM’s local time zone. If a Databricks cluster returns 2021-07-12 21:43:08 as a string, the JVM parses i...

Kafka client terminated with OffsetOutOfRangeException

Problem You have an Apache Spark application that is trying to fetch messages from an Apache Kafka source when it is terminated with a kafkashaded.org.apache.kafka.clients.consumer.OffsetOutOfRangeException error message. Cause Your Spark application is trying to fetch expired data offsets from Kafka. We generally see this in these two scenarios: Sc...