Query executor

At this stage we have an optimized execution plan. This plan is compiled to become an executable code. Then, if there are enough resources (memory, CPU) it is executed by the query executor. The operators in the plan (JOIN, SORT BY …) can be executed in a sequential or parallel way; it’s up to the executor. To get and write its data, the query executor interacts with the data manager, which is the next part of the article.