diff --git a/LICENSE b/LICENSE
index 55808fb5..2f5af69a 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2023 CMU Database Group
+Copyright (c) 2023-2024 CMU Database Group
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/datafusion-optd-cli/src/command.rs b/datafusion-optd-cli/src/command.rs
index 90c16a92..290804c9 100644
--- a/datafusion-optd-cli/src/command.rs
+++ b/datafusion-optd-cli/src/command.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
diff --git a/datafusion-optd-cli/src/exec.rs b/datafusion-optd-cli/src/exec.rs
index 86f9d309..0b14ef4f 100644
--- a/datafusion-optd-cli/src/exec.rs
+++ b/datafusion-optd-cli/src/exec.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
diff --git a/datafusion-optd-cli/src/lib.rs b/datafusion-optd-cli/src/lib.rs
index 7eb3cb51..8b4bda29 100644
--- a/datafusion-optd-cli/src/lib.rs
+++ b/datafusion-optd-cli/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
diff --git a/datafusion-optd-cli/src/main.rs b/datafusion-optd-cli/src/main.rs
index 520884f4..d59d4147 100644
--- a/datafusion-optd-cli/src/main.rs
+++ b/datafusion-optd-cli/src/main.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
diff --git a/optd-adaptive-demo/src/bin/optd-adaptive-three-join.rs b/optd-adaptive-demo/src/bin/optd-adaptive-three-join.rs
index 74b75595..3898a759 100644
--- a/optd-adaptive-demo/src/bin/optd-adaptive-three-join.rs
+++ b/optd-adaptive-demo/src/bin/optd-adaptive-three-join.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use console::Style;
diff --git a/optd-adaptive-demo/src/bin/optd-adaptive-tpch-q8.rs b/optd-adaptive-demo/src/bin/optd-adaptive-tpch-q8.rs
index f731391c..8be5af97 100644
--- a/optd-adaptive-demo/src/bin/optd-adaptive-tpch-q8.rs
+++ b/optd-adaptive-demo/src/bin/optd-adaptive-tpch-q8.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 use std::time::Duration;
 
diff --git a/optd-core/src/cascades.rs b/optd-core/src/cascades.rs
index e69486e1..2325f00b 100644
--- a/optd-core/src/cascades.rs
+++ b/optd-core/src/cascades.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! The core cascades optimizer implementation.
 
 mod memo;
diff --git a/optd-core/src/cascades/memo.rs b/optd-core/src/cascades/memo.rs
index adf81239..142ca11b 100644
--- a/optd-core/src/cascades/memo.rs
+++ b/optd-core/src/cascades/memo.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::any::Any;
 use std::collections::hash_map::Entry;
 use std::collections::{HashMap, HashSet};
diff --git a/optd-core/src/cascades/optimizer.rs b/optd-core/src/cascades/optimizer.rs
index 993fd7c7..dd6d5f34 100644
--- a/optd-core/src/cascades/optimizer.rs
+++ b/optd-core/src/cascades/optimizer.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::{BTreeSet, HashMap, HashSet, VecDeque};
 use std::fmt::Display;
 use std::sync::Arc;
diff --git a/optd-core/src/cascades/tasks.rs b/optd-core/src/cascades/tasks.rs
index 412f97f7..07d3205a 100644
--- a/optd-core/src/cascades/tasks.rs
+++ b/optd-core/src/cascades/tasks.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::Result;
 
 use super::{CascadesOptimizer, Memo};
diff --git a/optd-core/src/cascades/tasks/apply_rule.rs b/optd-core/src/cascades/tasks/apply_rule.rs
index 236c9bfd..2db820ff 100644
--- a/optd-core/src/cascades/tasks/apply_rule.rs
+++ b/optd-core/src/cascades/tasks/apply_rule.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use anyhow::Result;
diff --git a/optd-core/src/cascades/tasks/explore_group.rs b/optd-core/src/cascades/tasks/explore_group.rs
index 87637089..f2a47daa 100644
--- a/optd-core/src/cascades/tasks/explore_group.rs
+++ b/optd-core/src/cascades/tasks/explore_group.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::Result;
 use tracing::trace;
 
diff --git a/optd-core/src/cascades/tasks/optimize_expression.rs b/optd-core/src/cascades/tasks/optimize_expression.rs
index b37155bb..9c900e90 100644
--- a/optd-core/src/cascades/tasks/optimize_expression.rs
+++ b/optd-core/src/cascades/tasks/optimize_expression.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::Result;
 use tracing::trace;
 
diff --git a/optd-core/src/cascades/tasks/optimize_group.rs b/optd-core/src/cascades/tasks/optimize_group.rs
index e119e18f..2863af8c 100644
--- a/optd-core/src/cascades/tasks/optimize_group.rs
+++ b/optd-core/src/cascades/tasks/optimize_group.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::Result;
 use tracing::trace;
 
diff --git a/optd-core/src/cascades/tasks/optimize_inputs.rs b/optd-core/src/cascades/tasks/optimize_inputs.rs
index ab0a6be3..c8c5a958 100644
--- a/optd-core/src/cascades/tasks/optimize_inputs.rs
+++ b/optd-core/src/cascades/tasks/optimize_inputs.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::Result;
 use itertools::Itertools;
 use tracing::trace;
diff --git a/optd-core/src/cost.rs b/optd-core/src/cost.rs
index 3018d3b4..b7307414 100644
--- a/optd-core/src/cost.rs
+++ b/optd-core/src/cost.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use crate::cascades::{CascadesOptimizer, Memo, RelNodeContext};
 use crate::nodes::{ArcPredNode, NodeType};
 
diff --git a/optd-core/src/heuristics.rs b/optd-core/src/heuristics.rs
index 84a63e11..26f83fb2 100644
--- a/optd-core/src/heuristics.rs
+++ b/optd-core/src/heuristics.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 mod optimizer;
 
 pub use optimizer::{ApplyOrder, HeuristicsOptimizer};
diff --git a/optd-core/src/heuristics/optimizer.rs b/optd-core/src/heuristics/optimizer.rs
index bf35a58f..dbd9f722 100644
--- a/optd-core/src/heuristics/optimizer.rs
+++ b/optd-core/src/heuristics/optimizer.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::any::Any;
 use std::collections::HashMap;
 use std::sync::Arc;
diff --git a/optd-core/src/lib.rs b/optd-core/src/lib.rs
index 24ba051e..b6708b99 100644
--- a/optd-core/src/lib.rs
+++ b/optd-core/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 #![allow(clippy::new_without_default)]
 
 pub mod cascades;
diff --git a/optd-core/src/nodes.rs b/optd-core/src/nodes.rs
index c9b09742..3af1d8f7 100644
--- a/optd-core/src/nodes.rs
+++ b/optd-core/src/nodes.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! The RelNode is the basic data structure of the optimizer. It is dynamically typed and is
 //! the internal representation of the plan nodes.
 
diff --git a/optd-core/src/optimizer.rs b/optd-core/src/optimizer.rs
index 46e075e8..89f14874 100644
--- a/optd-core/src/optimizer.rs
+++ b/optd-core/src/optimizer.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::Result;
 
 use crate::nodes::{ArcPlanNode, NodeType, PlanNodeOrGroup};
diff --git a/optd-core/src/property.rs b/optd-core/src/property.rs
index 47e6cb8c..95445d6e 100644
--- a/optd-core/src/property.rs
+++ b/optd-core/src/property.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::any::Any;
 use std::fmt::{Debug, Display};
 
diff --git a/optd-core/src/rules.rs b/optd-core/src/rules.rs
index fef6c52f..0442eca1 100644
--- a/optd-core/src/rules.rs
+++ b/optd-core/src/rules.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 mod ir;
 
 use std::fmt::{Display, Formatter};
diff --git a/optd-core/src/rules/ir.rs b/optd-core/src/rules/ir.rs
index 6efc8a98..90a3b0b3 100644
--- a/optd-core/src/rules/ir.rs
+++ b/optd-core/src/rules/ir.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use crate::nodes::NodeType;
 
 pub enum RuleMatcher<T: NodeType> {
diff --git a/optd-datafusion-bridge/src/from_optd.rs b/optd-datafusion-bridge/src/from_optd.rs
index 7ef0a723..5346a021 100644
--- a/optd-datafusion-bridge/src/from_optd.rs
+++ b/optd-datafusion-bridge/src/from_optd.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashMap;
 use std::sync::Arc;
 
diff --git a/optd-datafusion-bridge/src/into_optd.rs b/optd-datafusion-bridge/src/into_optd.rs
index 39e06f53..238a7a00 100644
--- a/optd-datafusion-bridge/src/into_optd.rs
+++ b/optd-datafusion-bridge/src/into_optd.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use anyhow::{bail, Result};
 use datafusion::common::DFSchema;
 use datafusion::logical_expr::{self, logical_plan, LogicalPlan, Operator};
diff --git a/optd-datafusion-bridge/src/lib.rs b/optd-datafusion-bridge/src/lib.rs
index 1a9cccf7..d99d9d08 100644
--- a/optd-datafusion-bridge/src/lib.rs
+++ b/optd-datafusion-bridge/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 #![allow(clippy::new_without_default)]
 
 mod from_optd;
diff --git a/optd-datafusion-bridge/src/physical_collector.rs b/optd-datafusion-bridge/src/physical_collector.rs
index 9100b6e0..d2d10705 100644
--- a/optd-datafusion-bridge/src/physical_collector.rs
+++ b/optd-datafusion-bridge/src/physical_collector.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 use std::task::{Context, Poll};
 
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats.rs b/optd-datafusion-repr-adv-cost/src/adv_stats.rs
index 8c39a136..952f0b6b 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 mod agg;
 mod filter;
 mod join;
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/agg.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/agg.rs
index c2b5cb57..0b457123 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/agg.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/agg.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_datafusion_repr::plan_nodes::{ArcDfPredNode, DfReprPredNode, ListPred};
 use optd_datafusion_repr::properties::column_ref::{
     BaseTableColumnRef, ColumnRef, GroupColumnRefs,
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/filter.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/filter.rs
index 00a294ad..5850d59c 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/filter.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/filter.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::ops::Bound;
 
 use optd_datafusion_repr::plan_nodes::{
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/filter/in_list.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/filter/in_list.rs
index 7e6a1210..869cf6a9 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/filter/in_list.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/filter/in_list.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_datafusion_repr::plan_nodes::{
     ColumnRefPred, ConstantPred, DfPredType, DfReprPredNode, InListPred,
 };
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/filter/like.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/filter/like.rs
index 094ba5a6..825bab39 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/filter/like.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/filter/like.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use datafusion::arrow::array::StringArray;
 use datafusion::arrow::compute::like;
 use optd_datafusion_repr::plan_nodes::{
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/join.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/join.rs
index b15d7f50..5aa8fb6c 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/join.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/join.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashSet;
 
 use itertools::Itertools;
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/limit.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/limit.rs
index b5be86aa..ebb8c382 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/limit.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/limit.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_datafusion_repr::plan_nodes::{ArcDfPredNode, ConstantPred, DfReprPredNode};
 use serde::de::DeserializeOwned;
 use serde::Serialize;
diff --git a/optd-datafusion-repr-adv-cost/src/adv_stats/stats.rs b/optd-datafusion-repr-adv-cost/src/adv_stats/stats.rs
index 4953e0fb..fb66903c 100644
--- a/optd-datafusion-repr-adv-cost/src/adv_stats/stats.rs
+++ b/optd-datafusion-repr-adv-cost/src/adv_stats/stats.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashMap;
 use std::sync::Arc;
 
diff --git a/optd-datafusion-repr-adv-cost/src/lib.rs b/optd-datafusion-repr-adv-cost/src/lib.rs
index 40505641..2205ca8f 100644
--- a/optd-datafusion-repr-adv-cost/src/lib.rs
+++ b/optd-datafusion-repr-adv-cost/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::{Arc, Mutex};
 
 use adv_stats::stats::{
diff --git a/optd-datafusion-repr/src/cost.rs b/optd-datafusion-repr/src/cost.rs
index be2468fa..c7c84f89 100644
--- a/optd-datafusion-repr/src/cost.rs
+++ b/optd-datafusion-repr/src/cost.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod adaptive_cost;
 pub mod base_cost;
 
diff --git a/optd-datafusion-repr/src/cost/adaptive_cost.rs b/optd-datafusion-repr/src/cost/adaptive_cost.rs
index 7c2460c9..8a6c7b29 100644
--- a/optd-datafusion-repr/src/cost/adaptive_cost.rs
+++ b/optd-datafusion-repr/src/cost/adaptive_cost.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashMap;
 use std::sync::{Arc, Mutex};
 
diff --git a/optd-datafusion-repr/src/cost/base_cost.rs b/optd-datafusion-repr/src/cost/base_cost.rs
index 9d4c2136..ad442094 100644
--- a/optd-datafusion-repr/src/cost/base_cost.rs
+++ b/optd-datafusion-repr/src/cost/base_cost.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashMap;
 
 use itertools::Itertools;
diff --git a/optd-datafusion-repr/src/explain.rs b/optd-datafusion-repr/src/explain.rs
index 179a06db..d7eaa686 100644
--- a/optd-datafusion-repr/src/explain.rs
+++ b/optd-datafusion-repr/src/explain.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::{PlanNodeMeta, PlanNodeMetaMap};
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/lib.rs b/optd-datafusion-repr/src/lib.rs
index 0866c43b..e18af468 100644
--- a/optd-datafusion-repr/src/lib.rs
+++ b/optd-datafusion-repr/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 #![allow(clippy::new_without_default)]
 
 use std::collections::HashMap;
diff --git a/optd-datafusion-repr/src/memo_ext.rs b/optd-datafusion-repr/src/memo_ext.rs
index eee82082..642dd711 100644
--- a/optd-datafusion-repr/src/memo_ext.rs
+++ b/optd-datafusion-repr/src/memo_ext.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! Memo table extensions
 
 use std::collections::{BTreeSet, HashMap};
diff --git a/optd-datafusion-repr/src/optimizer_ext.rs b/optd-datafusion-repr/src/optimizer_ext.rs
index 7e7eaa21..64191c6c 100644
--- a/optd-datafusion-repr/src/optimizer_ext.rs
+++ b/optd-datafusion-repr/src/optimizer_ext.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::PlanNodeOrGroup;
 use optd_core::optimizer::Optimizer;
 
diff --git a/optd-datafusion-repr/src/plan_nodes.rs b/optd-datafusion-repr/src/plan_nodes.rs
index 225aeab3..72f1a766 100644
--- a/optd-datafusion-repr/src/plan_nodes.rs
+++ b/optd-datafusion-repr/src/plan_nodes.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! Typed interface of plan nodes.
 
 mod agg;
diff --git a/optd-datafusion-repr/src/plan_nodes/agg.rs b/optd-datafusion-repr/src/plan_nodes/agg.rs
index 645ac49c..e9e22edf 100644
--- a/optd-datafusion-repr/src/plan_nodes/agg.rs
+++ b/optd-datafusion-repr/src/plan_nodes/agg.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use super::macros::define_plan_node;
 use super::predicates::ListPred;
 use super::{ArcDfPlanNode, DfNodeType, DfPlanNode, DfReprPlanNode};
diff --git a/optd-datafusion-repr/src/plan_nodes/empty_relation.rs b/optd-datafusion-repr/src/plan_nodes/empty_relation.rs
index 9eb490c6..dedc42ff 100644
--- a/optd-datafusion-repr/src/plan_nodes/empty_relation.rs
+++ b/optd-datafusion-repr/src/plan_nodes/empty_relation.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use bincode;
diff --git a/optd-datafusion-repr/src/plan_nodes/filter.rs b/optd-datafusion-repr/src/plan_nodes/filter.rs
index 64619629..7c08a9bd 100644
--- a/optd-datafusion-repr/src/plan_nodes/filter.rs
+++ b/optd-datafusion-repr/src/plan_nodes/filter.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use super::macros::define_plan_node;
 use super::{ArcDfPlanNode, ArcDfPredNode, DfNodeType, DfPlanNode, DfReprPlanNode};
 
diff --git a/optd-datafusion-repr/src/plan_nodes/join.rs b/optd-datafusion-repr/src/plan_nodes/join.rs
index dfcf4422..84dbc033 100644
--- a/optd-datafusion-repr/src/plan_nodes/join.rs
+++ b/optd-datafusion-repr/src/plan_nodes/join.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use core::fmt;
 use std::fmt::Display;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/limit.rs b/optd-datafusion-repr/src/plan_nodes/limit.rs
index d35bf2e0..b71ef7d4 100644
--- a/optd-datafusion-repr/src/plan_nodes/limit.rs
+++ b/optd-datafusion-repr/src/plan_nodes/limit.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use super::macros::define_plan_node;
 use super::{ArcDfPlanNode, ArcDfPredNode, DfNodeType, DfPlanNode, DfReprPlanNode};
 
diff --git a/optd-datafusion-repr/src/plan_nodes/macros.rs b/optd-datafusion-repr/src/plan_nodes/macros.rs
index 5cd0645b..a674ec1e 100644
--- a/optd-datafusion-repr/src/plan_nodes/macros.rs
+++ b/optd-datafusion-repr/src/plan_nodes/macros.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 macro_rules! define_plan_node {
     (
         $struct_name:ident : $meta_typ:tt,
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates.rs b/optd-datafusion-repr/src/plan_nodes/predicates.rs
index da3f22e2..895c4469 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 mod between_pred;
 mod bin_op_pred;
 mod cast_pred;
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/between_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/between_pred.rs
index 38babffc..04ae48ac 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/between_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/between_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::PlanNodeMetaMap;
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/bin_op_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/bin_op_pred.rs
index 22f3a660..a96230f0 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/bin_op_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/bin_op_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::PlanNodeMetaMap;
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/cast_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/cast_pred.rs
index d1245023..cb8163e8 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/cast_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/cast_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use arrow_schema::DataType;
 use optd_core::nodes::PlanNodeMetaMap;
 use pretty_xmlish::Pretty;
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/column_ref_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/column_ref_pred.rs
index 9e061455..347110df 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/column_ref_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/column_ref_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::{PlanNodeMetaMap, Value};
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/constant_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/constant_pred.rs
index 2a10afb1..c95c10e5 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/constant_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/constant_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use arrow_schema::{DataType, IntervalUnit};
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/data_type_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/data_type_pred.rs
index b96fd890..f9493dc3 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/data_type_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/data_type_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use arrow_schema::DataType;
 use optd_core::nodes::PlanNodeMetaMap;
 use pretty_xmlish::Pretty;
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/extern_column_ref_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/extern_column_ref_pred.rs
index 991bf834..49a83093 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/extern_column_ref_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/extern_column_ref_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::{PlanNodeMetaMap, Value};
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/func_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/func_pred.rs
index 98fb7c3f..b61e1e53 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/func_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/func_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::PlanNodeMetaMap;
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/in_list_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/in_list_pred.rs
index d3625f31..30971c22 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/in_list_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/in_list_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::{PlanNodeMetaMap, Value};
 use pretty_xmlish::Pretty;
 
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/like_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/like_pred.rs
index 840f8f74..d2b32340 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/like_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/like_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use optd_core::nodes::{PlanNodeMetaMap, Value};
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/list_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/list_pred.rs
index ff95ddc7..d032fd71 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/list_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/list_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use itertools::Itertools;
 use optd_core::nodes::PlanNodeMetaMap;
 use pretty_xmlish::Pretty;
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/log_op_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/log_op_pred.rs
index 34cc1853..73517caf 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/log_op_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/log_op_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fmt::Display;
 
 use optd_core::nodes::PlanNodeMetaMap;
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/sort_order_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/sort_order_pred.rs
index 43ac4037..4e34e50f 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/sort_order_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/sort_order_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fmt::Display;
 
 use optd_core::nodes::PlanNodeMetaMap;
diff --git a/optd-datafusion-repr/src/plan_nodes/predicates/un_op_pred.rs b/optd-datafusion-repr/src/plan_nodes/predicates/un_op_pred.rs
index 1ae08e48..8cc592f5 100644
--- a/optd-datafusion-repr/src/plan_nodes/predicates/un_op_pred.rs
+++ b/optd-datafusion-repr/src/plan_nodes/predicates/un_op_pred.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fmt::Display;
 
 use optd_core::nodes::PlanNodeMetaMap;
diff --git a/optd-datafusion-repr/src/plan_nodes/projection.rs b/optd-datafusion-repr/src/plan_nodes/projection.rs
index 1697806c..8a1a079a 100644
--- a/optd-datafusion-repr/src/plan_nodes/projection.rs
+++ b/optd-datafusion-repr/src/plan_nodes/projection.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use super::macros::define_plan_node;
 use super::{ArcDfPlanNode, DfNodeType, DfPlanNode, DfReprPlanNode, ListPred};
 
diff --git a/optd-datafusion-repr/src/plan_nodes/scan.rs b/optd-datafusion-repr/src/plan_nodes/scan.rs
index 6a0f0fec..a93baa67 100644
--- a/optd-datafusion-repr/src/plan_nodes/scan.rs
+++ b/optd-datafusion-repr/src/plan_nodes/scan.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use optd_core::nodes::PlanNodeMetaMap;
diff --git a/optd-datafusion-repr/src/plan_nodes/sort.rs b/optd-datafusion-repr/src/plan_nodes/sort.rs
index 2558ea60..aef3427a 100644
--- a/optd-datafusion-repr/src/plan_nodes/sort.rs
+++ b/optd-datafusion-repr/src/plan_nodes/sort.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use super::macros::define_plan_node;
 use super::{ArcDfPlanNode, DfNodeType, DfPlanNode, DfReprPlanNode, ListPred};
 
diff --git a/optd-datafusion-repr/src/plan_nodes/subquery.rs b/optd-datafusion-repr/src/plan_nodes/subquery.rs
index aebf9379..abd400bc 100644
--- a/optd-datafusion-repr/src/plan_nodes/subquery.rs
+++ b/optd-datafusion-repr/src/plan_nodes/subquery.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use super::macros::define_plan_node;
 use super::{
     ArcDfPlanNode, ArcDfPredNode, DfNodeType, DfPlanNode, DfReprPlanNode, JoinType, ListPred,
diff --git a/optd-datafusion-repr/src/properties.rs b/optd-datafusion-repr/src/properties.rs
index 0e0af840..98004f8f 100644
--- a/optd-datafusion-repr/src/properties.rs
+++ b/optd-datafusion-repr/src/properties.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod column_ref;
 pub mod schema;
 
diff --git a/optd-datafusion-repr/src/properties/column_ref.rs b/optd-datafusion-repr/src/properties/column_ref.rs
index 117ebf2c..7141af96 100644
--- a/optd-datafusion-repr/src/properties/column_ref.rs
+++ b/optd-datafusion-repr/src/properties/column_ref.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashSet;
 use std::ops::Deref;
 use std::sync::Arc;
diff --git a/optd-datafusion-repr/src/properties/schema.rs b/optd-datafusion-repr/src/properties/schema.rs
index 5f359ce5..3055e373 100644
--- a/optd-datafusion-repr/src/properties/schema.rs
+++ b/optd-datafusion-repr/src/properties/schema.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use itertools::Itertools;
diff --git a/optd-datafusion-repr/src/rules.rs b/optd-datafusion-repr/src/rules.rs
index 8e792b31..20f883c3 100644
--- a/optd-datafusion-repr/src/rules.rs
+++ b/optd-datafusion-repr/src/rules.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 mod eliminate_duplicated_expr;
 mod eliminate_limit;
 mod filter;
diff --git a/optd-datafusion-repr/src/rules/eliminate_duplicated_expr.rs b/optd-datafusion-repr/src/rules/eliminate_duplicated_expr.rs
index 082e5ecb..4ec00947 100644
--- a/optd-datafusion-repr/src/rules/eliminate_duplicated_expr.rs
+++ b/optd-datafusion-repr/src/rules/eliminate_duplicated_expr.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashSet;
 
 use optd_core::nodes::PlanNodeOrGroup;
diff --git a/optd-datafusion-repr/src/rules/eliminate_limit.rs b/optd-datafusion-repr/src/rules/eliminate_limit.rs
index 64903bd2..c1968dce 100644
--- a/optd-datafusion-repr/src/rules/eliminate_limit.rs
+++ b/optd-datafusion-repr/src/rules/eliminate_limit.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::PlanNodeOrGroup;
 use optd_core::optimizer::Optimizer;
 use optd_core::rules::{Rule, RuleMatcher};
diff --git a/optd-datafusion-repr/src/rules/filter.rs b/optd-datafusion-repr/src/rules/filter.rs
index f6318155..77c85419 100644
--- a/optd-datafusion-repr/src/rules/filter.rs
+++ b/optd-datafusion-repr/src/rules/filter.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashSet;
 
 use optd_core::nodes::PlanNodeOrGroup;
diff --git a/optd-datafusion-repr/src/rules/filter_pushdown.rs b/optd-datafusion-repr/src/rules/filter_pushdown.rs
index 15608963..30c0d0b2 100644
--- a/optd-datafusion-repr/src/rules/filter_pushdown.rs
+++ b/optd-datafusion-repr/src/rules/filter_pushdown.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! This rule is designed to be applied heuristically (read: all the time, blindly).
 //! However, pushing a filter is not *always* better (but it usually is). If cost is
 //! to be taken into account, each transposition step can be done separately
diff --git a/optd-datafusion-repr/src/rules/joins.rs b/optd-datafusion-repr/src/rules/joins.rs
index d8355e2a..5a7fdbc3 100644
--- a/optd-datafusion-repr/src/rules/joins.rs
+++ b/optd-datafusion-repr/src/rules/joins.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::vec;
 
 use optd_core::nodes::PlanNodeOrGroup;
diff --git a/optd-datafusion-repr/src/rules/macros.rs b/optd-datafusion-repr/src/rules/macros.rs
index c3928140..47703e66 100644
--- a/optd-datafusion-repr/src/rules/macros.rs
+++ b/optd-datafusion-repr/src/rules/macros.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 macro_rules! define_matcher {
     ( ( $typ:expr $(, $children:tt )* ) ) => {
         RuleMatcher::MatchNode {
diff --git a/optd-datafusion-repr/src/rules/physical.rs b/optd-datafusion-repr/src/rules/physical.rs
index a5497d44..2bbfa0e6 100644
--- a/optd-datafusion-repr/src/rules/physical.rs
+++ b/optd-datafusion-repr/src/rules/physical.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::sync::Arc;
 
 use optd_core::nodes::{PlanNode, PlanNodeOrGroup};
diff --git a/optd-datafusion-repr/src/rules/project_transpose.rs b/optd-datafusion-repr/src/rules/project_transpose.rs
index 14be13d5..b18f2019 100644
--- a/optd-datafusion-repr/src/rules/project_transpose.rs
+++ b/optd-datafusion-repr/src/rules/project_transpose.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod project_filter_transpose;
 pub mod project_join_transpose;
 pub mod project_merge;
diff --git a/optd-datafusion-repr/src/rules/project_transpose/project_filter_transpose.rs b/optd-datafusion-repr/src/rules/project_transpose/project_filter_transpose.rs
index 7de4c1c0..a31da316 100644
--- a/optd-datafusion-repr/src/rules/project_transpose/project_filter_transpose.rs
+++ b/optd-datafusion-repr/src/rules/project_transpose/project_filter_transpose.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::vec;
 
 use itertools::Itertools;
diff --git a/optd-datafusion-repr/src/rules/project_transpose/project_join_transpose.rs b/optd-datafusion-repr/src/rules/project_transpose/project_join_transpose.rs
index b1e0986c..dfe8cb79 100644
--- a/optd-datafusion-repr/src/rules/project_transpose/project_join_transpose.rs
+++ b/optd-datafusion-repr/src/rules/project_transpose/project_join_transpose.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::vec;
 
 use optd_core::nodes::PlanNodeOrGroup;
diff --git a/optd-datafusion-repr/src/rules/project_transpose/project_merge.rs b/optd-datafusion-repr/src/rules/project_transpose/project_merge.rs
index e73e3927..7b290645 100644
--- a/optd-datafusion-repr/src/rules/project_transpose/project_merge.rs
+++ b/optd-datafusion-repr/src/rules/project_transpose/project_merge.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::PlanNodeOrGroup;
 use optd_core::optimizer::Optimizer;
 use optd_core::rules::{Rule, RuleMatcher};
diff --git a/optd-datafusion-repr/src/rules/project_transpose/project_transpose_common.rs b/optd-datafusion-repr/src/rules/project_transpose/project_transpose_common.rs
index 8cf0eaa3..b973c7a2 100644
--- a/optd-datafusion-repr/src/rules/project_transpose/project_transpose_common.rs
+++ b/optd-datafusion-repr/src/rules/project_transpose/project_transpose_common.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use crate::plan_nodes::{ArcDfPredNode, ColumnRefPred, DfReprPredNode, ListPred, PredExt};
 
 /// This struct holds the mapping from original columns to projected columns.
diff --git a/optd-datafusion-repr/src/rules/subquery.rs b/optd-datafusion-repr/src/rules/subquery.rs
index b6e0bf84..17a6e0a6 100644
--- a/optd-datafusion-repr/src/rules/subquery.rs
+++ b/optd-datafusion-repr/src/rules/subquery.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod depjoin_pushdown;
 
 pub use depjoin_pushdown::{
diff --git a/optd-datafusion-repr/src/rules/subquery/depjoin_pushdown.rs b/optd-datafusion-repr/src/rules/subquery/depjoin_pushdown.rs
index 206bc9ba..6e60f122 100644
--- a/optd-datafusion-repr/src/rules/subquery/depjoin_pushdown.rs
+++ b/optd-datafusion-repr/src/rules/subquery/depjoin_pushdown.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::nodes::{PlanNodeOrGroup, PredNode};
 // TODO: No push past join
 // TODO: Sideways information passing??
diff --git a/optd-datafusion-repr/src/testing.rs b/optd-datafusion-repr/src/testing.rs
index b5f26e7d..a9526d65 100644
--- a/optd-datafusion-repr/src/testing.rs
+++ b/optd-datafusion-repr/src/testing.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 mod dummy_cost;
 mod tpch_catalog;
 
diff --git a/optd-datafusion-repr/src/testing/dummy_cost.rs b/optd-datafusion-repr/src/testing/dummy_cost.rs
index 3aac5d3c..5cafc276 100644
--- a/optd-datafusion-repr/src/testing/dummy_cost.rs
+++ b/optd-datafusion-repr/src/testing/dummy_cost.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use optd_core::cascades::{CascadesOptimizer, NaiveMemo, RelNodeContext};
 use optd_core::cost::{Cost, CostModel, Statistics};
 use value_bag::ValueBag;
diff --git a/optd-datafusion-repr/src/testing/tpch_catalog.rs b/optd-datafusion-repr/src/testing/tpch_catalog.rs
index 41e2ea24..81023474 100644
--- a/optd-datafusion-repr/src/testing/tpch_catalog.rs
+++ b/optd-datafusion-repr/src/testing/tpch_catalog.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use core::panic;
 
 use crate::plan_nodes::ConstantType;
diff --git a/optd-gungnir/src/lib.rs b/optd-gungnir/src/lib.rs
index 759fe93b..f0b07635 100644
--- a/optd-gungnir/src/lib.rs
+++ b/optd-gungnir/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 #![allow(clippy::new_without_default)]
 
 pub mod stats;
diff --git a/optd-gungnir/src/stats.rs b/optd-gungnir/src/stats.rs
index 69a60d4b..b32315af 100644
--- a/optd-gungnir/src/stats.rs
+++ b/optd-gungnir/src/stats.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod counter;
 pub mod hyperloglog;
 pub mod misragries;
diff --git a/optd-gungnir/src/stats/counter.rs b/optd-gungnir/src/stats/counter.rs
index 387ad36a..58d300c3 100644
--- a/optd-gungnir/src/stats/counter.rs
+++ b/optd-gungnir/src/stats/counter.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! A hash-based Counter implementation that will track exact frequencies for
 //! an array of prespecified elements.
 
diff --git a/optd-gungnir/src/stats/hyperloglog.rs b/optd-gungnir/src/stats/hyperloglog.rs
index d2beff75..dae5973b 100644
--- a/optd-gungnir/src/stats/hyperloglog.rs
+++ b/optd-gungnir/src/stats/hyperloglog.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! Implementation of the HyperLogLog data structure as described in Flajolet et al. paper:
 //! "HyperLogLog: the analysis of a near-optimal cardinality estimation algorithm" (2007).
 //! For more details, refer to:
diff --git a/optd-gungnir/src/stats/misragries.rs b/optd-gungnir/src/stats/misragries.rs
index d68c395b..5cd11e8a 100644
--- a/optd-gungnir/src/stats/misragries.rs
+++ b/optd-gungnir/src/stats/misragries.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! Implementation of the Misra-Gries Summary data structure as described in  
 //! the Cormode et al. paper: "Misra-Gries Summaries" (2014).
 //! We further refine the algorithm to ensure that K elements will always be
diff --git a/optd-gungnir/src/stats/murmur2.rs b/optd-gungnir/src/stats/murmur2.rs
index 7a27426b..b7de8e59 100644
--- a/optd-gungnir/src/stats/murmur2.rs
+++ b/optd-gungnir/src/stats/murmur2.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! Implementation of the MurmurHash2 function, for 64b outputs, by Austin Appleby (2008).
 //! Note: Assumes little-endian machines.
 
diff --git a/optd-gungnir/src/stats/tdigest.rs b/optd-gungnir/src/stats/tdigest.rs
index 6273a103..83c9f289 100644
--- a/optd-gungnir/src/stats/tdigest.rs
+++ b/optd-gungnir/src/stats/tdigest.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! Simplified implementation of the TDigest data structure as described in
 //! Ted Dunning's paper:
 //! "Computing Extremely Accurate Quantiles Using t-Digests" (2019).
diff --git a/optd-gungnir/src/utils.rs b/optd-gungnir/src/utils.rs
index 646eaff2..10a76ecc 100644
--- a/optd-gungnir/src/utils.rs
+++ b/optd-gungnir/src/utils.rs
@@ -1 +1,6 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod arith_encoder;
diff --git a/optd-gungnir/src/utils/arith_encoder.rs b/optd-gungnir/src/utils/arith_encoder.rs
index 855e6d20..ba96794d 100644
--- a/optd-gungnir/src/utils/arith_encoder.rs
+++ b/optd-gungnir/src/utils/arith_encoder.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 //! This module provides an encoder that converts alpha-numeric strings
 //! into f64 values, designed to maintain the natural ordering of strings.
 //!
diff --git a/optd-perfbench/src/benchmark.rs b/optd-perfbench/src/benchmark.rs
index 623bebb4..cf1b11b4 100644
--- a/optd-perfbench/src/benchmark.rs
+++ b/optd-perfbench/src/benchmark.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use serde::{Deserialize, Serialize};
 
 use crate::job::JobKitConfig;
diff --git a/optd-perfbench/src/cardbench.rs b/optd-perfbench/src/cardbench.rs
index f1088419..ef2aa541 100644
--- a/optd-perfbench/src/cardbench.rs
+++ b/optd-perfbench/src/cardbench.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashMap;
 use std::path::Path;
 
diff --git a/optd-perfbench/src/datafusion_dbms.rs b/optd-perfbench/src/datafusion_dbms.rs
index dd15accb..2cf8e44c 100644
--- a/optd-perfbench/src/datafusion_dbms.rs
+++ b/optd-perfbench/src/datafusion_dbms.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fs::{self, File};
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex};
diff --git a/optd-perfbench/src/job.rs b/optd-perfbench/src/job.rs
index 18e6f391..22875dc2 100644
--- a/optd-perfbench/src/job.rs
+++ b/optd-perfbench/src/job.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fmt::{self, Display, Formatter};
 use std::fs::File;
 use std::path::{Path, PathBuf};
diff --git a/optd-perfbench/src/lib.rs b/optd-perfbench/src/lib.rs
index 3b4a99e3..163fa1a7 100644
--- a/optd-perfbench/src/lib.rs
+++ b/optd-perfbench/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 pub mod benchmark;
 pub mod cardbench;
 mod datafusion_dbms;
diff --git a/optd-perfbench/src/main.rs b/optd-perfbench/src/main.rs
index f486720c..107ca018 100644
--- a/optd-perfbench/src/main.rs
+++ b/optd-perfbench/src/main.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fs;
 use std::path::Path;
 
diff --git a/optd-perfbench/src/postgres_dbms.rs b/optd-perfbench/src/postgres_dbms.rs
index 1324ad76..abc652cc 100644
--- a/optd-perfbench/src/postgres_dbms.rs
+++ b/optd-perfbench/src/postgres_dbms.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::fs;
 use std::io::Cursor;
 use std::path::{Path, PathBuf};
diff --git a/optd-perfbench/src/shell.rs b/optd-perfbench/src/shell.rs
index 768af7ee..c14c129d 100644
--- a/optd-perfbench/src/shell.rs
+++ b/optd-perfbench/src/shell.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::path::{Path, PathBuf};
 use std::process::{Command, Output};
 use std::{fs, io, str};
diff --git a/optd-perfbench/src/tpch.rs b/optd-perfbench/src/tpch.rs
index b3f6bd45..dcf3e831 100644
--- a/optd-perfbench/src/tpch.rs
+++ b/optd-perfbench/src/tpch.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::env::consts::OS;
 use std::fmt::{self, Display, Formatter};
 use std::fs::File;
diff --git a/optd-perfbench/src/truecard.rs b/optd-perfbench/src/truecard.rs
index cd776bbb..7e14c263 100644
--- a/optd-perfbench/src/truecard.rs
+++ b/optd-perfbench/src/truecard.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashMap;
 use std::fs::{self, File};
 use std::path::{Path, PathBuf};
diff --git a/optd-perfbench/tests/cardtest_integration.rs b/optd-perfbench/tests/cardtest_integration.rs
index 85c83ff2..d2fa103f 100644
--- a/optd-perfbench/tests/cardtest_integration.rs
+++ b/optd-perfbench/tests/cardtest_integration.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 #[cfg(test)]
 mod tests {
     use std::fs;
diff --git a/optd-sqlplannertest/src/bin/planner_test_apply.rs b/optd-sqlplannertest/src/bin/planner_test_apply.rs
index 0e76aa4e..f555bfba 100644
--- a/optd-sqlplannertest/src/bin/planner_test_apply.rs
+++ b/optd-sqlplannertest/src/bin/planner_test_apply.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::path::Path;
 
 use anyhow::Result;
diff --git a/optd-sqlplannertest/src/lib.rs b/optd-sqlplannertest/src/lib.rs
index d69ce3c4..d96a6a66 100644
--- a/optd-sqlplannertest/src/lib.rs
+++ b/optd-sqlplannertest/src/lib.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::collections::HashSet;
 use std::sync::Arc;
 
diff --git a/optd-sqlplannertest/tests/planner_test.rs b/optd-sqlplannertest/tests/planner_test.rs
index 5aa2476d..4e98fa64 100644
--- a/optd-sqlplannertest/tests/planner_test.rs
+++ b/optd-sqlplannertest/tests/planner_test.rs
@@ -1,3 +1,8 @@
+// Copyright (c) 2023-2024 CMU Database Group
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
 use std::path::Path;
 
 use anyhow::Result;