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….
The problem One common pattern we see in some analytical workloads is the repeated use of the same, often times expensive expression. Look at the following query plan for example: The expression JSON_PARSE(features) is used 6 times, and casted to different ROW structures for further processing. Traditionally, Presto would just execute the expression 6 times,…
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…