Module planner 

Query planner: SQL AST → Volcano operator tree.

Converts a parsed SQL SelectStmt into a tree of physical operators that can be executed row-at-a-time via the Volcano model.

SelectStmt
  → FROM → SeqScan / Join tree
  → WHERE → Filter
  → GROUP BY + aggregates → HashAggregate
  → HAVING → Filter
  → SELECT → Project
  → ORDER BY → Sort
  → LIMIT/OFFSET → Limit

Structs

QueryPlanner

Query planner that converts SQL AST to Volcano operator trees.

Functions

explain_select

Generate a textual EXPLAIN representation for a SELECT statement.