diff --git a/bustubx/src/catalog/column.rs b/bustubx/src/catalog/column.rs
index 1e56019..df20ff0 100644
--- a/bustubx/src/catalog/column.rs
+++ b/bustubx/src/catalog/column.rs
@@ -28,10 +28,4 @@ impl Column {
             nullable: false,
         }
     }
-
-    pub fn from_sqlparser_column(column_def: &ColumnDef) -> Self {
-        let column_name = column_def.name.to_string();
-        let column_type: DataType = (&column_def.data_type).try_into().unwrap();
-        Self::new(column_name, column_type)
-    }
 }
diff --git a/bustubx/src/planner/logical_planner/plan_expr.rs b/bustubx/src/planner/logical_planner/bind_expr.rs
similarity index 89%
rename from bustubx/src/planner/logical_planner/plan_expr.rs
rename to bustubx/src/planner/logical_planner/bind_expr.rs
index 97851a2..8e4151d 100644
--- a/bustubx/src/planner/logical_planner/plan_expr.rs
+++ b/bustubx/src/planner/logical_planner/bind_expr.rs
@@ -4,22 +4,22 @@ use crate::planner::LogicalPlanner;
 use crate::{BustubxError, BustubxResult};
 
 impl LogicalPlanner<'_> {
-    pub fn plan_expr(&self, sql: &sqlparser::ast::Expr) -> BustubxResult<Expr> {
+    pub fn bind_expr(&self, sql: &sqlparser::ast::Expr) -> BustubxResult<Expr> {
         match sql {
             sqlparser::ast::Expr::Identifier(ident) => Ok(Expr::Column(ColumnExpr {
                 relation: None,
                 name: ident.value.clone(),
             })),
             sqlparser::ast::Expr::BinaryOp { left, op, right } => {
-                let left = Box::new(self.plan_expr(left)?);
-                let right = Box::new(self.plan_expr(right)?);
+                let left = Box::new(self.bind_expr(left)?);
+                let right = Box::new(self.bind_expr(right)?);
                 Ok(Expr::BinaryExpr(BinaryExpr {
                     left,
                     op: op.try_into()?,
                     right,
                 }))
             }
-            sqlparser::ast::Expr::Value(value) => self.plan_value(value),
+            sqlparser::ast::Expr::Value(value) => self.bind_value(value),
             sqlparser::ast::Expr::CompoundIdentifier(idents) => match idents.as_slice() {
                 [col] => Ok(Expr::Column(ColumnExpr {
                     relation: None,
@@ -56,7 +56,7 @@ impl LogicalPlanner<'_> {
         }
     }
 
-    pub fn plan_value(&self, value: &sqlparser::ast::Value) -> BustubxResult<Expr> {
+    pub fn bind_value(&self, value: &sqlparser::ast::Value) -> BustubxResult<Expr> {
         match value {
             sqlparser::ast::Value::Number(s, _) => {
                 let num: i64 = s.parse::<i64>().map_err(|e| {
diff --git a/bustubx/src/planner/logical_planner/logical_planner.rs b/bustubx/src/planner/logical_planner/logical_planner.rs
index 3b276ef..e238f7d 100644
--- a/bustubx/src/planner/logical_planner/logical_planner.rs
+++ b/bustubx/src/planner/logical_planner/logical_planner.rs
@@ -34,11 +34,11 @@ impl<'a> LogicalPlanner<'a> {
         }
     }
 
-    pub fn plan_order_by_expr(
+    pub fn bind_order_by_expr(
         &self,
         order_by: &sqlparser::ast::OrderByExpr,
     ) -> BustubxResult<OrderByExpr> {
-        let expr = self.plan_expr(&order_by.expr)?;
+        let expr = self.bind_expr(&order_by.expr)?;
         Ok(OrderByExpr {
             expr: Box::new(expr),
             asc: order_by.asc.unwrap_or(true),
@@ -46,7 +46,7 @@ impl<'a> LogicalPlanner<'a> {
         })
     }
 
-    pub fn plan_table_name(
+    pub fn bind_table_name(
         &self,
         table_name: &sqlparser::ast::ObjectName,
     ) -> BustubxResult<TableReference> {
diff --git a/bustubx/src/planner/logical_planner/mod.rs b/bustubx/src/planner/logical_planner/mod.rs
index f78bfee..da1ac41 100644
--- a/bustubx/src/planner/logical_planner/mod.rs
+++ b/bustubx/src/planner/logical_planner/mod.rs
@@ -1,7 +1,7 @@
+mod bind_expr;
 mod logical_planner;
 mod plan_create_index;
 mod plan_create_table;
-mod plan_expr;
 mod plan_insert;
 mod plan_query;
 mod plan_set_expr;
diff --git a/bustubx/src/planner/logical_planner/plan_create_index.rs b/bustubx/src/planner/logical_planner/plan_create_index.rs
index ee15eb9..32d2b37 100644
--- a/bustubx/src/planner/logical_planner/plan_create_index.rs
+++ b/bustubx/src/planner/logical_planner/plan_create_index.rs
@@ -16,10 +16,10 @@ impl<'a> LogicalPlanner<'a> {
             .map_or(Err(BustubxError::Plan("".to_string())), |ident| {
                 Ok(ident.value.clone())
             })?;
-        let table = self.plan_table_name(table_name)?;
+        let table = self.bind_table_name(table_name)?;
         let mut columns_expr = vec![];
         for col in columns.iter() {
-            let col_expr = self.plan_order_by_expr(&col)?;
+            let col_expr = self.bind_order_by_expr(&col)?;
             columns_expr.push(col_expr);
         }
         let table_schema = self
diff --git a/bustubx/src/planner/logical_planner/plan_create_table.rs b/bustubx/src/planner/logical_planner/plan_create_table.rs
index 6889415..07398be 100644
--- a/bustubx/src/planner/logical_planner/plan_create_table.rs
+++ b/bustubx/src/planner/logical_planner/plan_create_table.rs
@@ -11,7 +11,7 @@ impl<'a> LogicalPlanner<'a> {
         name: &sqlparser::ast::ObjectName,
         column_defs: &Vec<sqlparser::ast::ColumnDef>,
     ) -> BustubxResult<LogicalPlan> {
-        let name = self.plan_table_name(name)?;
+        let name = self.bind_table_name(name)?;
         let mut columns = vec![];
         for col_def in column_defs {
             columns.push(Column::new(
diff --git a/bustubx/src/planner/logical_planner/plan_insert.rs b/bustubx/src/planner/logical_planner/plan_insert.rs
index fb493c6..cd4984f 100644
--- a/bustubx/src/planner/logical_planner/plan_insert.rs
+++ b/bustubx/src/planner/logical_planner/plan_insert.rs
@@ -13,7 +13,7 @@ impl<'a> LogicalPlanner<'a> {
         source: &sqlparser::ast::Query,
     ) -> BustubxResult<LogicalPlan> {
         let values = self.plan_set_expr(source.body.as_ref())?;
-        let table = self.plan_table_name(table_name)?;
+        let table = self.bind_table_name(table_name)?;
         let table_schema = self
             .context
             .catalog
diff --git a/bustubx/src/planner/logical_planner/plan_query.rs b/bustubx/src/planner/logical_planner/plan_query.rs
index 50564f2..3835d76 100644
--- a/bustubx/src/planner/logical_planner/plan_query.rs
+++ b/bustubx/src/planner/logical_planner/plan_query.rs
@@ -25,7 +25,7 @@ impl<'a> LogicalPlanner<'a> {
 
         let mut order_by_exprs = vec![];
         for order in order_by {
-            order_by_exprs.push(self.plan_order_by_expr(order)?);
+            order_by_exprs.push(self.bind_order_by_expr(order)?);
         }
 
         Ok(LogicalPlan::Sort(Sort {
@@ -48,7 +48,7 @@ impl<'a> LogicalPlanner<'a> {
         let limit = match limit {
             None => None,
             Some(limit_expr) => {
-                let n = match self.plan_expr(&limit_expr)? {
+                let n = match self.bind_expr(&limit_expr)? {
                     Expr::Literal(lit) => match lit.value {
                         ScalarValue::Int64(Some(v)) if v >= 0 => Ok(v as usize),
                         _ => Err(BustubxError::Plan(format!(
@@ -67,7 +67,7 @@ impl<'a> LogicalPlanner<'a> {
 
         let offset = match offset {
             None => 0,
-            Some(offset_expr) => match self.plan_expr(&offset_expr.value)? {
+            Some(offset_expr) => match self.bind_expr(&offset_expr.value)? {
                 Expr::Literal(lit) => match lit.value {
                     ScalarValue::Int64(Some(v)) => {
                         if v < 0 {
diff --git a/bustubx/src/planner/logical_planner/plan_set_expr.rs b/bustubx/src/planner/logical_planner/plan_set_expr.rs
index a1b0e20..48b0de8 100644
--- a/bustubx/src/planner/logical_planner/plan_set_expr.rs
+++ b/bustubx/src/planner/logical_planner/plan_set_expr.rs
@@ -35,11 +35,11 @@ impl LogicalPlanner<'_> {
         let mut exprs = vec![];
         for select_item in project {
             match select_item {
-                sqlparser::ast::SelectItem::UnnamedExpr(expr) => exprs.push(self.plan_expr(expr)?),
+                sqlparser::ast::SelectItem::UnnamedExpr(expr) => exprs.push(self.bind_expr(expr)?),
                 sqlparser::ast::SelectItem::ExprWithAlias { expr, alias } => {
                     exprs.push(Expr::Alias(Alias {
                         name: alias.value.clone(),
-                        expr: Box::new(self.plan_expr(expr)?),
+                        expr: Box::new(self.bind_expr(expr)?),
                     }))
                 }
                 sqlparser::ast::SelectItem::Wildcard(_) => {
@@ -80,7 +80,7 @@ impl LogicalPlanner<'_> {
         match selection {
             None => Ok(input),
             Some(predicate) => {
-                let predicate = self.plan_expr(predicate)?;
+                let predicate = self.bind_expr(predicate)?;
                 Ok(LogicalPlan::Filter(Filter {
                     input: Arc::new(input),
                     predicate,
@@ -162,7 +162,7 @@ impl LogicalPlanner<'_> {
     ) -> BustubxResult<LogicalPlan> {
         match constraint {
             sqlparser::ast::JoinConstraint::On(expr) => {
-                let expr = self.plan_expr(expr)?;
+                let expr = self.bind_expr(expr)?;
                 let schema = Arc::new(build_join_schema(left.schema(), right.schema(), join_type)?);
                 Ok(LogicalPlan::Join(Join {
                     left: Arc::new(left),
@@ -205,7 +205,7 @@ impl LogicalPlanner<'_> {
         match relation {
             sqlparser::ast::TableFactor::Table { name, alias, .. } => {
                 // TODO handle alias
-                let table_ref = self.plan_table_name(name)?;
+                let table_ref = self.bind_table_name(name)?;
                 // TODO get schema by full table name
                 let schema = self
                     .context
@@ -241,7 +241,7 @@ impl LogicalPlanner<'_> {
         for row in values.rows.iter() {
             let mut record = vec![];
             for item in row {
-                record.push(self.plan_expr(item)?);
+                record.push(self.bind_expr(item)?);
             }
             result.push(record);
         }