PlanningPerf: Add global default ConfigOptions

Author: alamb

datafusion/common/src/config.rs

@@ -36,6 +36,7 @@ use std::fmt::{self, Display};
 use std::str::FromStr;
 #[cfg(feature = "parquet_encryption")]
 use std::sync::Arc;
+use std::sync::LazyLock;
 
 /// A macro that wraps a configuration struct and automatically derives
 /// [`Default`] and [`ConfigField`] for it, allowing it to be used
@@ -1382,12 +1383,21 @@ impl ConfigField for ConfigOptions {
 /// (FFI) based configuration extensions.
 pub const DATAFUSION_FFI_CONFIG_NAMESPACE: &str = "datafusion_ffi";
 
+/// Global default configuration options
+static DEFAULT_CONFIG: LazyLock<Arc<ConfigOptions>> =
+    LazyLock::new(|| Arc::new(ConfigOptions::new()));
+
 impl ConfigOptions {
     /// Creates a new [`ConfigOptions`] with default values
     pub fn new() -> Self {
         Self::default()
     }
 
+    /// Return a reference to the default configuration options
+    pub fn default_arc() -> Arc<Self> {
+        Arc::clone(&DEFAULT_CONFIG)
+    }
+
     /// Set extensions to provided value
     pub fn with_extensions(mut self, extensions: Extensions) -> Self {
         self.extensions = extensions;

datafusion/expr/src/simplify.rs

@@ -45,7 +45,7 @@ impl Default for SimplifyContext {
         Self {
             schema: Arc::new(DFSchema::empty()),
             query_execution_start_time: None,
-            config_options: Arc::new(ConfigOptions::default()),
+            config_options: ConfigOptions::default_arc(),
         }
     }
 }