fix: change name for schema btree + fix benchmark

core/benches/benchmark.rs

@@ -1,6 +1,9 @@
 use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
 use pprof::criterion::{Output, PProfProfiler};
-use std::sync::Arc;
+use std::{
+    sync::Arc,
+    time::{Duration, Instant},
+};
 use turso_core::{Database, PlatformIO};
 
 fn rusqlite_open() -> rusqlite::Connection {
@@ -74,27 +77,43 @@ fn bench_alter(criterion: &mut Criterion) {
 
     let mut group = criterion.benchmark_group("`ALTER TABLE _ RENAME TO _`");
 
-    let stmts = ["CREATE TABLE x(a)", "ALTER TABLE x RENAME TO y", "DROP TABLE y"];
-
     group.bench_function(BenchmarkId::new("limbo_rename_table", ""), |b| {
         #[allow(clippy::arc_with_non_send_sync)]
         let io = Arc::new(PlatformIO::new().unwrap());
         let db = Database::open_file(io.clone(), "../testing/schema_5k.db", false, false).unwrap();
         let conn = db.connect().unwrap();
-        b.iter(|| {
-            for stmt in stmts {
-                conn.execute(stmt).unwrap();
-            }
+        b.iter_custom(|iters| {
+            (0..iters)
+                .map(|_| {
+                    conn.execute("CREATE TABLE x(a)").unwrap();
+                    let elapsed = {
+                        let start = Instant::now();
+                        conn.execute("ALTER TABLE x RENAME TO y").unwrap();
+                        start.elapsed()
+                    };
+                    conn.execute("DROP TABLE y").unwrap();
+                    elapsed
+                })
+                .sum()
         });
     });
 
     if enable_rusqlite {
         group.bench_function(BenchmarkId::new("sqlite_rename_table", ""), |b| {
             let conn = rusqlite::Connection::open("../testing/schema_5k.db").unwrap();
-            b.iter(|| {
-                for stmt in stmts {
-                    conn.execute(stmt, ()).unwrap();
-                }
+            b.iter_custom(|iters| {
+                (0..iters)
+                    .map(|_| {
+                        conn.execute("CREATE TABLE x(a)", ()).unwrap();
+                        let elapsed = {
+                            let start = Instant::now();
+                            conn.execute("ALTER TABLE x RENAME TO y", ()).unwrap();
+                            start.elapsed()
+                        };
+                        conn.execute("DROP TABLE y", ()).unwrap();
+                        elapsed
+                    })
+                    .sum()
             });
         });
     }

core/vdbe/execute.rs

@@ -6753,12 +6753,6 @@ pub fn op_rename_table(
     };
 
     let conn = program.connection.clone();
-    // set auto commit to false in order for parse schema to not commit changes as transaction state is stored in connection,
-    // and we use the same connection for nested query.
-    let previous_auto_commit = conn.auto_commit.get();
-    conn.auto_commit.set(false);
-
-    let stmt = conn.prepare("SELECT * FROM sqlite_schema")?;
 
     conn.with_schema_mut(|schema| {
         schema.indexes.remove(from).map(|mut indexes| {
@@ -6770,20 +6764,25 @@ pub fn op_rename_table(
             schema.indexes.insert(to.to_owned(), indexes);
         });
 
-        let mut table_ref = schema
+        let mut table = schema
             .tables
             .remove(from)
             .expect("table being renamed should be in schema");
-        let table = Arc::make_mut(&mut table_ref);
 
-        let Table::BTree(btree) = table else {
-            panic!("only btree tables can be renamed");
-        };
+        {
+            let table = Arc::make_mut(&mut table);
 
-        schema.tables.insert(to.to_owned(), table_ref);
+            let Table::BTree(btree) = table else {
+                panic!("only btree tables can be renamed");
+            };
+
+            let btree = Arc::make_mut(btree);
+            btree.name = to.to_owned();
+        }
+
+        schema.tables.insert(to.to_owned(), table);
     });
 
-    conn.auto_commit.set(previous_auto_commit);
     state.pc += 1;
     Ok(InsnFunctionStepResult::Step)
 }