Depending on the complexity of your SQL query there are many, often exponential, query plans that return the same result. However, the performance of each plan can vary drastically; taking only seconds to finish or days given the chosen plan.That places a significant burden on analysts who will then have to know how to write performant SQL. This problem gets worse as the complexity of questions and SQL queries increases. In the abse
Starburst provides connectors to the most popular data sources included in many of these connectors are a number of exclusive enhancements. Many of Starburst’s connectors when compared with open source Trino have enhanced extensions such as parallelism, pushdown and table statistics, that drastically improve the overall performance. Parallelism distributes query processing across workers, and uses many connections to the data source a
Dynamic filtering optimizations significantly improve the performance of queries with selective joins by avoiding reading of data that would be filtered by join condition. In this respect, dynamic filtering is similar to join pushdown discussed above, however it is the equivalent of inner join pushdown across data sources. As a consequence we derive the performance benefits associated with selective joins when performing federated queri
架构B站SQL On Hadoop 整体架构在介绍Presto在B站的实践之前,先从整体来看看SQL在B站的使用情况,在B站的离线平台,核心由三大计算引擎Presto、Spark、Hive以及分布式存储系统HDFS和调度系统Yarn组成。如下架构图所示,我们的ADHOC、BI、DQC以及数据探查等服务都是通过自研的Dispatcher路由服务来进行统一SQL调度,Dispatcher会结合查询