exec

Overview ¶

Package exec drives a physical operator tree to completion.

It is a SERIAL driver, and it stayed one. This doc used to say "the seam where morsel-driven parallelism arrives in v0.2 is here and only here", and step 5 put parallelism somewhere else entirely: physical.parallelOp wraps the pipeline below this loop, so a query runs on N threads without exec knowing. The prediction was wrong about the place, and the reason is worth keeping — parallelOp's round-robin dispatch is what BUYS input order structurally, and a scheduler here would have to re-establish it, which is the harder problem.

What is still true: nothing here knows about spilling, budgets or temporary files. Every one of those lives below, which is why three operators gained the ability to spill without this file changing.