Remove not used expression functions

Signed-off-by: Xuanwo <github@xuanwo.io>

Author: Xuanwo

src/query/legacy-planners/src/lib.rs

@@ -51,7 +51,6 @@ pub use plan_expression_function::sum;
 pub use plan_expression_literal::lit;
 pub use plan_expression_literal::lit_null;
 pub use plan_expression_monotonicity::ExpressionMonotonicityVisitor;
-pub use plan_expression_validator::validate_clustering;
 pub use plan_expression_validator::validate_expression;
 pub use plan_expression_validator::validate_function_arg;
 pub use plan_expression_visitor::ExpressionVisitor;

src/query/legacy-planners/src/plan_expression_validator.rs

@@ -110,35 +110,3 @@ pub fn validate_expression(expr: &Expression, schema: &DataSchemaRef) -> Result<
         None => Ok(()),
     }
 }
-
-fn check_deterministic(op: &str) -> Result<()> {
-    let features = FunctionFactory::instance().get_features(op)?;
-    if !features.is_deterministic {
-        return Err(ErrorCode::InvalidClusterKeys(format!(
-            "Function `{}` is not valid for clustering",
-            op
-        )));
-    }
-    Ok(())
-}
-
-pub fn validate_clustering(expr: &Expression) -> Result<()> {
-    let validator = ExpressionValidator::new(&|expr: &Expression| match expr {
-        Expression::Literal { .. } => Ok(()),
-        Expression::Column { .. } => Ok(()),
-        Expression::Cast { .. } => Ok(()),
-        Expression::UnaryExpression { op, .. } => check_deterministic(op),
-        Expression::BinaryExpression { op, .. } => check_deterministic(op),
-        Expression::ScalarFunction { op, .. } => check_deterministic(op),
-        _ => Err(ErrorCode::InvalidClusterKeys(format!(
-            "Function `{}` is not valid for clustering",
-            expr.column_name()
-        ))),
-    });
-
-    let validator = expr.accept(validator)?;
-    match validator.error {
-        Some(err) => Err(err),
-        None => Ok(()),
-    }
-}