Overview Presto’s architecture originally only supported a single coordinator and a pool of workers. This has worked well for many years but created some challenges. To overcome these challenges, we came up with a new design with a disaggregated coordinator that allows the coordinator to be horizontally scaled out across a single pool of workers….
Function evaluation is a big part of projection CPU cost. Recently we optimized a set of functions that use TypedSet, e.g. map_concat, array_union, array_intersect, and array_except. By introducing a new OptimizedTypeSet, the above functions saw improvements in several dimensions: Furthermore, OptimizedTypeSet resolves the long standing issue of throwing EXCEEDED_FUNCTION_MEMORY_LIMIT for large incoming blocks: “The input…
In a multi-tenant system like Presto careful memory management is required to keep the system stable and prevent individual queries from taking over all the resources. However, tracking the memory usage of data structures in an application (Presto) running on the Java Virtual Machine (JVM) requires a significant amount of work. In addition, Presto is…