Remove some old feature flags around window functions

enable_value_window_function_fusion
enable_window_aggregation_fusion
enable_reduce_unnest_list_fusion

src/adapter/src/optimize.rs

@@ -251,10 +251,6 @@ impl From<&OptimizerConfig> for mz_sql::plan::HirToMirConfig {
         Self {
             enable_new_outer_join_lowering: config.features.enable_new_outer_join_lowering,
             enable_variadic_left_join_lowering: config.features.enable_variadic_left_join_lowering,
-            enable_value_window_function_fusion: config
-                .features
-                .enable_value_window_function_fusion,
-            enable_window_aggregation_fusion: config.features.enable_window_aggregation_fusion,
         }
     }
 }

src/compute-types/src/plan/lowering.rs

@@ -37,8 +37,6 @@ pub(super) struct Context {
     debug_info: LirDebugInfo,
     /// Whether to enable fusion of MFPs in reductions.
     enable_reduce_mfp_fusion: bool,
-    /// Whether to fuse `Reduce` with `FlatMap UnnestList` for better window function performance.
-    enable_reduce_unnest_list_fusion: bool,
 }
 
 impl Context {
@@ -51,7 +49,6 @@ impl Context {
                 id: GlobalId::Transient(0),
             },
             enable_reduce_mfp_fusion: features.enable_reduce_mfp_fusion,
-            enable_reduce_unnest_list_fusion: features.enable_reduce_unnest_list_fusion,
         }
     }
 
@@ -418,9 +415,6 @@ impl Context {
                 // it would be very hard to hunt down all these parts. (For example, key inference
                 // infers the group key as a unique key.)
                 let fused_with_reduce = 'fusion: {
-                    if !self.enable_reduce_unnest_list_fusion {
-                        break 'fusion None;
-                    }
                     if !matches!(func, TableFunc::UnnestList { .. }) {
                         break 'fusion None;
                     }
@@ -692,10 +686,9 @@ This is not expected to cause incorrect results, but could indicate a performanc
                 monotonic,
                 expected_group_size,
             } => {
-                if self.enable_reduce_unnest_list_fusion
-                    && aggregates
-                        .iter()
-                        .any(|agg| agg.func.can_fuse_with_unnest_list())
+                if aggregates
+                    .iter()
+                    .any(|agg| agg.func.can_fuse_with_unnest_list())
                 {
                     // This case should have been handled at the `MirRelationExpr::FlatMap` case
                     // above. But that has a pretty complicated pattern matching, so it's not

src/repr/src/optimize.rs

@@ -116,12 +116,6 @@ optimizer_feature_flags!({
     // Reoptimize imported views when building and optimizing a
     // `DataflowDescription` in the global MIR optimization phase.
     reoptimize_imported_views: bool,
-    // Enables the value window function fusion optimization.
-    enable_value_window_function_fusion: bool,
-    // See the feature flag of the same name.
-    enable_reduce_unnest_list_fusion: bool,
-    // See the feature flag of the same name.
-    enable_window_aggregation_fusion: bool,
     // See the feature flag of the same name.
     enable_reduce_reduction: bool,
 });

src/sql-parser/src/ast/defs/statement.rs

@@ -2328,9 +2328,6 @@ pub enum ClusterFeatureName {
     EnableEagerDeltaJoins,
     EnableVariadicLeftJoinLowering,
     EnableLetrecFixpointAnalysis,
-    EnableValueWindowFunctionFusion,
-    EnableReduceUnnestListFusion,
-    EnableWindowAggregationFusion,
 }
 
 impl WithOptionName for ClusterFeatureName {
@@ -2345,10 +2342,7 @@ impl WithOptionName for ClusterFeatureName {
             | Self::EnableNewOuterJoinLowering
             | Self::EnableEagerDeltaJoins
             | Self::EnableVariadicLeftJoinLowering
-            | Self::EnableLetrecFixpointAnalysis
-            | Self::EnableValueWindowFunctionFusion
-            | Self::EnableReduceUnnestListFusion
-            | Self::EnableWindowAggregationFusion => false,
+            | Self::EnableLetrecFixpointAnalysis => false,
         }
     }
 }
@@ -3894,9 +3888,6 @@ pub enum ExplainPlanOptionName {
     EnableEagerDeltaJoins,
     EnableVariadicLeftJoinLowering,
     EnableLetrecFixpointAnalysis,
-    EnableValueWindowFunctionFusion,
-    EnableReduceUnnestListFusion,
-    EnableWindowAggregationFusion,
 }
 
 impl WithOptionName for ExplainPlanOptionName {
@@ -3930,10 +3921,7 @@ impl WithOptionName for ExplainPlanOptionName {
             | Self::EnableNewOuterJoinLowering
             | Self::EnableEagerDeltaJoins
             | Self::EnableVariadicLeftJoinLowering
-            | Self::EnableLetrecFixpointAnalysis
-            | Self::EnableValueWindowFunctionFusion
-            | Self::EnableReduceUnnestListFusion
-            | Self::EnableWindowAggregationFusion => false,
+            | Self::EnableLetrecFixpointAnalysis => false,
         }
     }
 }

src/sql/src/plan/lowering.rs

@@ -136,19 +136,13 @@ pub struct Config {
     pub enable_new_outer_join_lowering: bool,
     /// Enable outer join lowering implemented in database-issues#7561.
     pub enable_variadic_left_join_lowering: bool,
-    /// See the feature flag of the same name.
-    pub enable_value_window_function_fusion: bool,
-    /// See the feature flag of the same name.
-    pub enable_window_aggregation_fusion: bool,
 }
 
 impl From<&SystemVars> for Config {
     fn from(vars: &SystemVars) -> Self {
         Self {
             enable_new_outer_join_lowering: vars.enable_new_outer_join_lowering(),
             enable_variadic_left_join_lowering: vars.enable_variadic_left_join_lowering(),
-            enable_value_window_function_fusion: vars.enable_value_window_function_fusion(),
-            enable_window_aggregation_fusion: vars.enable_window_aggregation_fusion(),
         }
     }
 }

src/sql/src/plan/statement/ddl.rs

@@ -4414,10 +4414,7 @@ generate_extracted_config!(
     (EnableEagerDeltaJoins, Option<bool>, Default(None)),
     (EnableNewOuterJoinLowering, Option<bool>, Default(None)),
     (EnableVariadicLeftJoinLowering, Option<bool>, Default(None)),
-    (EnableLetrecFixpointAnalysis, Option<bool>, Default(None)),
-    (EnableValueWindowFunctionFusion, Option<bool>, Default(None)),
-    (EnableReduceUnnestListFusion, Option<bool>, Default(None)),
-    (EnableWindowAggregationFusion, Option<bool>, Default(None))
+    (EnableLetrecFixpointAnalysis, Option<bool>, Default(None))
 );
 
 /// Convert a [`CreateClusterStatement`] into a [`Plan`].
@@ -4554,9 +4551,6 @@ pub fn plan_create_cluster_inner(
             enable_new_outer_join_lowering,
             enable_variadic_left_join_lowering,
             enable_letrec_fixpoint_analysis,
-            enable_value_window_function_fusion,
-            enable_reduce_unnest_list_fusion,
-            enable_window_aggregation_fusion,
             seen: _,
         } = ClusterFeatureExtracted::try_from(features)?;
         let optimizer_feature_overrides = OptimizerFeatureOverrides {
@@ -4565,9 +4559,6 @@ pub fn plan_create_cluster_inner(
             enable_new_outer_join_lowering,
             enable_variadic_left_join_lowering,
             enable_letrec_fixpoint_analysis,
-            enable_value_window_function_fusion,
-            enable_reduce_unnest_list_fusion,
-            enable_window_aggregation_fusion,
             ..Default::default()
         };
 
@@ -4662,9 +4653,6 @@ pub fn unplan_create_cluster(
                 enable_new_outer_join_lowering,
                 enable_variadic_left_join_lowering,
                 enable_letrec_fixpoint_analysis,
-                enable_value_window_function_fusion,
-                enable_reduce_unnest_list_fusion,
-                enable_window_aggregation_fusion,
                 enable_reduce_reduction: _,
             } = optimizer_feature_overrides;
             let features_extracted = ClusterFeatureExtracted {
@@ -4675,9 +4663,6 @@ pub fn unplan_create_cluster(
                 enable_new_outer_join_lowering,
                 enable_variadic_left_join_lowering,
                 enable_letrec_fixpoint_analysis,
-                enable_value_window_function_fusion,
-                enable_reduce_unnest_list_fusion,
-                enable_window_aggregation_fusion,
             };
             let features = features_extracted.into_values(scx.catalog);
             let availability_zones = if availability_zones.is_empty() {

src/sql/src/plan/statement/dml.rs

@@ -368,10 +368,7 @@ generate_extracted_config!(
     (EnableNewOuterJoinLowering, Option<bool>, Default(None)),
     (EnableEagerDeltaJoins, Option<bool>, Default(None)),
     (EnableVariadicLeftJoinLowering, Option<bool>, Default(None)),
-    (EnableLetrecFixpointAnalysis, Option<bool>, Default(None)),
-    (EnableValueWindowFunctionFusion, Option<bool>, Default(None)),
-    (EnableReduceUnnestListFusion, Option<bool>, Default(None)),
-    (EnableWindowAggregationFusion, Option<bool>, Default(None))
+    (EnableLetrecFixpointAnalysis, Option<bool>, Default(None))
 );
 
 impl TryFrom<ExplainPlanOptionExtracted> for ExplainConfig {
@@ -422,9 +419,6 @@ impl TryFrom<ExplainPlanOptionExtracted> for ExplainConfig {
                 enable_cardinality_estimates: Default::default(),
                 persist_fast_path_limit: Default::default(),
                 reoptimize_imported_views: v.reoptimize_imported_views,
-                enable_value_window_function_fusion: v.enable_value_window_function_fusion,
-                enable_reduce_unnest_list_fusion: v.enable_reduce_unnest_list_fusion,
-                enable_window_aggregation_fusion: v.enable_window_aggregation_fusion,
                 enable_reduce_reduction: Default::default(),
             },
         })

src/sql/src/plan/transform_expr.rs

@@ -353,14 +353,8 @@ fn column_type(
 /// columns in the group.)
 pub fn fuse_window_functions(
     root: &mut HirRelationExpr,
-    context: &crate::plan::lowering::Context,
+    _context: &crate::plan::lowering::Context,
 ) -> Result<(), RecursionLimitError> {
-    if !(context.config.enable_value_window_function_fusion
-        || context.config.enable_window_aggregation_fusion)
-    {
-        return Ok(());
-    }
-
     impl HirScalarExpr {
         /// Similar to `MirScalarExpr::support`, but adapted to `HirScalarExpr` in a special way: it
         /// considers column references that target the root level.
@@ -589,7 +583,6 @@ pub fn fuse_window_functions(
                 // encounter these, because we just do one pass, but it's better to be
                 // robust against future code changes.)
                 !matches!(func, ValueWindowFunc::Fused(..))
-                    && context.config.enable_value_window_function_fusion
             }
             HirScalarExpr::Windowing(WindowExpr {
                 func:
@@ -598,10 +591,7 @@ pub fn fuse_window_functions(
                         ..
                     }),
                 ..
-            }) => {
-                !matches!(func, AggregateFunc::FusedWindowAgg { .. })
-                    && context.config.enable_window_aggregation_fusion
-            }
+            }) => !matches!(func, AggregateFunc::FusedWindowAgg { .. }),
             _ => false,
         }
     };

src/sql/src/session/vars/definitions.rs

@@ -2176,24 +2176,6 @@ feature_flags!(
         default: false,
         enable_for_item_parsing: false,
     },
-    {
-        name: enable_value_window_function_fusion,
-        desc: "Enables the value window function fusion optimization",
-        default: true,
-        enable_for_item_parsing: false,
-    },
-    {
-        name: enable_window_aggregation_fusion,
-        desc: "Enables the window aggregation fusion optimization",
-        default: true,
-        enable_for_item_parsing: false,
-    },
-    {
-        name: enable_reduce_unnest_list_fusion,
-        desc: "Enables fusing `Reduce` with `FlatMap UnnestList` for better window function performance",
-        default: true,
-        enable_for_item_parsing: false,
-    },
     {
         name: enable_continual_task_create,
         desc: "CREATE CONTINUAL TASK",
@@ -2230,9 +2212,6 @@ impl From<&super::SystemVars> for OptimizerFeatures {
             enable_variadic_left_join_lowering: vars.enable_variadic_left_join_lowering(),
             enable_letrec_fixpoint_analysis: vars.enable_letrec_fixpoint_analysis(),
             enable_cardinality_estimates: vars.enable_cardinality_estimates(),
-            enable_value_window_function_fusion: vars.enable_value_window_function_fusion(),
-            enable_reduce_unnest_list_fusion: vars.enable_reduce_unnest_list_fusion(),
-            enable_window_aggregation_fusion: vars.enable_window_aggregation_fusion(),
             enable_reduce_reduction: vars.enable_reduce_reduction(),
             persist_fast_path_limit: vars.persist_fast_path_limit(),
             reoptimize_imported_views: false,