prune based on upper bound

Signed-off-by: Alex Chi Z <iskyzh@gmail.com>

Author: skyzh

optd-core/src/cascades/memo.rs

@@ -352,7 +352,7 @@ impl<T: NodeType> NaiveMemo<T> {
     }
 
     fn verify_integrity(&self) {
-        if cfg!(debug_assertions) {
+        if false {
             let num_of_exprs = self.expr_id_to_expr_node.len();
             assert_eq!(num_of_exprs, self.expr_node_to_expr_id.len());
             assert_eq!(num_of_exprs, self.expr_id_to_group_id.len());

optd-core/src/cascades/optimizer.rs

@@ -248,7 +248,7 @@ impl<T: NodeType, M: Memo<T>> CascadesOptimizer<T, M> {
     fn fire_optimize_tasks(&mut self, group_id: GroupId) -> Result<()> {
         trace!(event = "fire_optimize_tasks", root_group_id = %group_id);
         self.tasks
-            .push_back(Box::new(OptimizeGroupTask::new(group_id)));
+            .push_back(Box::new(OptimizeGroupTask::new(group_id, None)));
         // get the task from the stack
         self.ctx.budget_used = false;
         let plan_space_begin = self.memo.estimated_plan_space();

optd-core/src/cascades/tasks/apply_rule.rs

@@ -21,14 +21,21 @@ pub struct ApplyRuleTask {
     rule_id: RuleId,
     expr_id: ExprId,
     exploring: bool,
+    upper_bound: Option<f64>,
 }
 
 impl ApplyRuleTask {
-    pub fn new(rule_id: RuleId, expr_id: ExprId, exploring: bool) -> Self {
+    pub fn new(
+        rule_id: RuleId,
+        expr_id: ExprId,
+        exploring: bool,
+        upper_bound: Option<f64>,
+    ) -> Self {
         Self {
             rule_id,
             expr_id,
             exploring,
+            upper_bound,
         }
     }
 }
@@ -181,13 +188,14 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for ApplyRuleTask {
                     let typ = expr.unwrap_typ();
                     if typ.is_logical() {
                         tasks.push(
-                            Box::new(OptimizeExpressionTask::new(expr_id, self.exploring))
+                            Box::new(OptimizeExpressionTask::new(expr_id, self.exploring, self.upper_bound))
                                 as Box<dyn Task<T, M>>,
                         );
                     } else {
                         tasks.push(Box::new(OptimizeInputsTask::new(
                             expr_id,
                             !optimizer.prop.disable_pruning,
+                            self.upper_bound
                         )) as Box<dyn Task<T, M>>);
                     }
                     optimizer.unmark_expr_explored(expr_id);

optd-core/src/cascades/tasks/explore_group.rs

@@ -14,11 +14,15 @@ use crate::nodes::NodeType;
 
 pub struct ExploreGroupTask {
     group_id: GroupId,
+    upper_bound: Option<f64>,
 }
 
 impl ExploreGroupTask {
-    pub fn new(group_id: GroupId) -> Self {
-        Self { group_id }
+    pub fn new(group_id: GroupId, upper_bound: Option<f64>) -> Self {
+        Self {
+            group_id,
+            upper_bound,
+        }
     }
 }
 
@@ -36,7 +40,7 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for ExploreGroupTask {
             let typ = optimizer.get_expr_memoed(expr).typ.clone();
             if typ.is_logical() {
                 tasks
-                    .push(Box::new(OptimizeExpressionTask::new(expr, true)) as Box<dyn Task<T, M>>);
+                    .push(Box::new(OptimizeExpressionTask::new(expr, true, self.upper_bound)) as Box<dyn Task<T, M>>);
             }
         }
         optimizer.mark_group_explored(self.group_id);

optd-core/src/cascades/tasks/optimize_expression.rs

@@ -16,11 +16,16 @@ use crate::rules::RuleMatcher;
 pub struct OptimizeExpressionTask {
     expr_id: ExprId,
     exploring: bool,
+    upper_bound: Option<f64>,
 }
 
 impl OptimizeExpressionTask {
-    pub fn new(expr_id: ExprId, exploring: bool) -> Self {
-        Self { expr_id, exploring }
+    pub fn new(expr_id: ExprId, exploring: bool, upper_bound: Option<f64>) -> Self {
+        Self {
+            expr_id,
+            exploring,
+            upper_bound,
+        }
     }
 }
 
@@ -53,12 +58,12 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeExpressionTask {
             }
             if top_matches(rule.matcher(), expr.typ.clone()) {
                 tasks.push(
-                    Box::new(ApplyRuleTask::new(rule_id, self.expr_id, self.exploring))
+                    Box::new(ApplyRuleTask::new(rule_id, self.expr_id, self.exploring, self.upper_bound))
                         as Box<dyn Task<T, M>>,
                 );
                 for &input_group_id in &expr.children {
                     tasks.push(
-                        Box::new(ExploreGroupTask::new(input_group_id)) as Box<dyn Task<T, M>>
+                        Box::new(ExploreGroupTask::new(input_group_id, self.upper_bound)) as Box<dyn Task<T, M>>
                     );
                 }
             }

optd-core/src/cascades/tasks/optimize_group.rs

@@ -15,11 +15,15 @@ use crate::nodes::NodeType;
 
 pub struct OptimizeGroupTask {
     group_id: GroupId,
+    upper_bound: Option<f64>,
 }
 
 impl OptimizeGroupTask {
-    pub fn new(group_id: GroupId) -> Self {
-        Self { group_id }
+    pub fn new(group_id: GroupId, upper_bound: Option<f64>) -> Self {
+        Self {
+            group_id,
+            upper_bound,
+        }
     }
 }
 
@@ -37,7 +41,7 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeGroupTask {
         for &expr in &exprs {
             let typ = optimizer.get_expr_memoed(expr).typ.clone();
             if typ.is_logical() {
-                tasks.push(Box::new(OptimizeExpressionTask::new(expr, false)) as Box<dyn Task<T, M>>);
+                tasks.push(Box::new(OptimizeExpressionTask::new(expr, false, self.upper_bound)) as Box<dyn Task<T, M>>);
             }
         }
         for &expr in &exprs {
@@ -46,6 +50,7 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeGroupTask {
                 tasks.push(Box::new(OptimizeInputsTask::new(
                     expr,
                     !optimizer.prop.disable_pruning,
+                    self.upper_bound
                 )) as Box<dyn Task<T, M>>);
             }
         }

optd-core/src/cascades/tasks/optimize_inputs.rs

@@ -42,22 +42,25 @@ pub struct OptimizeInputsTask {
     expr_id: ExprId,
     continue_from: Option<ContinueTask>,
     pruning: bool,
+    upper_bound: Option<f64>,
 }
 
 impl OptimizeInputsTask {
-    pub fn new(expr_id: ExprId, pruning: bool) -> Self {
+    pub fn new(expr_id: ExprId, pruning: bool, upper_bound: Option<f64>) -> Self {
         Self {
             expr_id,
             continue_from: None,
             pruning,
+            upper_bound,
         }
     }
 
-    fn continue_from(&self, cont: ContinueTask, pruning: bool) -> Self {
+    fn continue_from(&self, cont: ContinueTask, pruning: bool, upper_bound: Option<f64>) -> Self {
         Self {
             expr_id: self.expr_id,
             continue_from: Some(cont),
             pruning,
+            upper_bound,
         }
     }
 
@@ -153,6 +156,19 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeInputsTask {
 
         trace!(event = "task_begin", task = "optimize_inputs", expr_id = %self.expr_id, continue_from = %ContinueTaskDisplay(&self.continue_from), total_children = %children_group_ids.len());
 
+        let upper_bound = if self.pruning {
+            if let Some(upper_bound) = self.upper_bound {
+                Some(upper_bound)
+            } else if let Some(winner) = optimizer.get_group_info(group_id).winner.as_full_winner()
+            {
+                Some(winner.total_weighted_cost)
+            } else {
+                None
+            }
+        } else {
+            None
+        };
+
         if let Some(ContinueTask {
             next_group_idx,
             return_from_optimize_group,
@@ -219,9 +235,9 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeInputsTask {
                     winner_weighted_cost = %trace_fmt(&group_info.winner),
                     current_processing = %next_group_idx,
                     total_child_groups = %children_group_ids.len());
-                if let Some(winner) = group_info.winner.as_full_winner() {
+                if let Some(upper_bound) = upper_bound {
                     let cost_so_far = cost.weighted_cost(&total_cost);
-                    if winner.total_weighted_cost <= cost_so_far {
+                    if upper_bound <= cost_so_far {
                         trace!(event = "task_finish", task = "optimize_inputs", expr_id = %self.expr_id, result = "pruned");
                         return Ok(vec![]);
                     }
@@ -232,7 +248,7 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeInputsTask {
                 let child_group_id = children_group_ids[next_group_idx];
                 let group_idx = next_group_idx;
                 let child_group_info = optimizer.get_group_info(child_group_id);
-                if !child_group_info.winner.has_full_winner() {
+                let Some(child_winner) = child_group_info.winner.as_full_winner() else {
                     if !return_from_optimize_group {
                         trace!(event = "task_yield", task = "optimize_inputs", expr_id = %self.expr_id, group_idx = %group_idx, yield_to = "optimize_group", optimize_group_id = %child_group_id);
                         return Ok(vec![
@@ -242,22 +258,25 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeInputsTask {
                                     return_from_optimize_group: true,
                                 },
                                 self.pruning,
+                                upper_bound,
                             )) as Box<dyn Task<T, M>>,
-                            Box::new(OptimizeGroupTask::new(child_group_id)) as Box<dyn Task<T, M>>,
+                            Box::new(OptimizeGroupTask::new(child_group_id, upper_bound))
+                                as Box<dyn Task<T, M>>,
                         ]);
                     } else {
                         self.update_winner_impossible(optimizer);
                         trace!(event = "task_finish", task = "optimize_inputs", expr_id = %self.expr_id, result = "impossible");
                         return Ok(vec![]);
                     }
-                }
+                };
                 trace!(event = "task_yield", task = "optimize_inputs", expr_id = %self.expr_id, group_idx = %group_idx, yield_to = "next_optimize_input");
                 Ok(vec![Box::new(self.continue_from(
                     ContinueTask {
                         next_group_idx: group_idx + 1,
                         return_from_optimize_group: false,
                     },
                     self.pruning,
+                    upper_bound.map(|bound| bound - child_winner.total_weighted_cost),
                 )) as Box<dyn Task<T, M>>])
             } else {
                 self.update_winner(input_statistics_ref, operation_cost, total_cost, optimizer);
@@ -272,6 +291,7 @@ impl<T: NodeType, M: Memo<T>> Task<T, M> for OptimizeInputsTask {
                     return_from_optimize_group: false,
                 },
                 self.pruning,
+                upper_bound,
             )) as Box<dyn Task<T, M>>])
         }
     }