By the time 1. 4 ends, the planner has produced one PlannedStmt. Inside it is an execution tree built from Plan nodes, frozen into a form you can follow step by step, something like "go into the primary key index on users, fetch the one matching row, then output that whole row.
Source: [Dev.to](https://dev.to/joonghyukshin/15-executor-how-results-come-back-5978)