The Azure Synapse Runtime for Apache Spark 3.4 was released as generally available (GA) on November 21, 2023, succeeding Apache Spark 3.3 in Synapse Analytics. It offers performance improvements, new features, and enhanced security. Users were encouraged to upgrade from older runtimes like 3.3 to 3.4, with a recommended migration plan involving assessment of compatibility, codebase analysis, and creation of new Spark pools for testing purposes[1]. Regarding its retirement, Azure announced that the Azure Synapse Runtime for Apache Spark 3.4 will be retired in March 2026. This means support for this runtime will end at that time, and customers should plan to migrate their workloads to newer supported runtimes before this date[3][5]. In summary: Release : Apache Spark 3.4 runtime for Azure Synapse became GA in November 2023. Upgrade advice : Users should test and migrate workloads from versions 2.4, 3.1, 3.2, or 3.3 to 3.4 to benefit from improvements. End of support / Retirement :...