Query execution components
PostgreSQL query execution involves the following four key components:
- Parser: This performs syntax and semantic checking of the SQL string
- Rewriter: This changes the query is some cases; for example, if the query is against a view, the rewriter will modify the query so that it goes against the base tables instead of the view
- Planner: This key component comes up with a plan of execution
- Executor: This executes the plan generated by the planner
Planner
The planner's job is to come up with a plan of execution. A plan is a tree consisting of one or more nodes. Each node, on execution, returns zero or more tuples. These tuples are used by the parent nodes in the tree until we reach the root node, which returns the results to the ...
Get PostgreSQL for Data Architects now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
