Only recompute schema in TypeCoercion when necessary

datafusion/expr/src/expr_schema.rs

@@ -508,7 +508,7 @@ fn field_for_index(
 
 /// cast subquery in InSubquery/ScalarSubquery to a given type.
 pub fn cast_subquery(subquery: Subquery, cast_to_type: &DataType) -> Result<Subquery> {
-    if subquery.subquery.schema().field(0).data_type() == cast_to_type {
+    if subquery.data_type() == cast_to_type {
         return Ok(subquery);
     }
 

datafusion/expr/src/logical_plan/plan.rs

@@ -2685,6 +2685,11 @@ impl Subquery {
             outer_ref_columns: self.outer_ref_columns.clone(),
         }
     }
+
+    /// Returns the type of the first column of the subquery
+    pub fn data_type(&self) -> &DataType {
+        self.subquery.schema().fields()[0].data_type()
+    }
 }
 
 impl Debug for Subquery {

datafusion/optimizer/src/analyzer/mod.rs

@@ -22,7 +22,7 @@ use log::debug;
 
 use datafusion_common::config::ConfigOptions;
 use datafusion_common::instant::Instant;
-use datafusion_common::tree_node::{TreeNode, TreeNodeRecursion};
+use datafusion_common::tree_node::{Transformed, TreeNode, TreeNodeRecursion};
 use datafusion_common::{DataFusionError, Result};
 use datafusion_expr::expr::Exists;
 use datafusion_expr::expr::InSubquery;
@@ -62,6 +62,17 @@ pub trait AnalyzerRule {
     /// Rewrite `plan`
     fn analyze(&self, plan: LogicalPlan, config: &ConfigOptions) -> Result<LogicalPlan>;
 
+    /// Rewrite a plan indicating if the plan was modified
+    /// The default implementation calls `analyze`
+    fn rewrite(
+        &self,
+        plan: LogicalPlan,
+        config: &ConfigOptions,
+    ) -> Result<Transformed<LogicalPlan>> {
+        let new_plan = self.analyze(plan, config)?;
+        Ok(Transformed::yes(new_plan))
+    }
+
     /// A human readable name for this analyzer rule
     fn name(&self) -> &str;
 }