Local execution
Local execution is a mode where a single threaded program runs a physical graph. This is great for testing and debugging.
Overview
A LocalTopology consists of nodes and edges. Each edge contains a FIFO queue, where components can put tuples in at the end and read from components. The topology runs from
Inputs
Input nodes read the entire input (table, file, …) at the beginning. Thus, the input stays in memory during the job execution.
Execution
An execution step transforms the topology.
Examples
Filter&Project
For queries of type
SELECT f.a, f.b
FROM f
WHERE f.x = 5