antithesis: Add DROP INDEX parallel driver

antithesis-tests/stress-composer/parallel_driver_drop_index.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env -S python3 -u
+
+import json
+
+import turso
+from antithesis.random import get_random
+
+# Get initial state
+try:
+    con_init = turso.connect("init_state.db")
+except Exception as e:
+    print(f"Error connecting to database: {e}")
+    exit(0)
+
+cur_init = con_init.cursor()
+
+# Connect to the main database
+try:
+    con = turso.connect("stress_composer.db", experimental_indexes=True)
+except Exception as e:
+    print(f"Failed to open stress_composer.db. Exiting... {e}")
+    exit(0)
+
+cur = con.cursor()
+
+# Get all user-created indexes (excluding automatic indexes)
+existing_indexes = cur.execute("""
+    SELECT name, tbl_name FROM sqlite_master 
+    WHERE type = 'index' 
+    AND sql IS NOT NULL
+    AND name NOT LIKE 'sqlite_%'
+""").fetchall()
+
+if not existing_indexes:
+    print("No indexes available to drop")
+    exit(0)
+
+# Select a random index to drop
+selected_idx = get_random() % len(existing_indexes)
+index_name, table_name = existing_indexes[selected_idx]
+
+print(f"Selected index: {index_name} on table {table_name}")
+print(f"Total indexes available: {len(existing_indexes)}")
+
+try:
+    # Drop the index
+    drop_stmt = f"DROP INDEX {index_name}"
+    print(f"Dropping index: {drop_stmt}")
+    cur.execute(drop_stmt)
+    
+    # Remove index information from init_state.db
+    cur_init.execute(f"""
+        DELETE FROM indexes 
+        WHERE idx_name = '{index_name}'
+    """)
+    con_init.commit()
+    
+    print(f"Successfully dropped index: {index_name}")
+except turso.OperationalError as e:
+    print(f"Failed to drop index: {e}")
+    con.rollback()
+except Exception as e:
+    # Handle case where index might not exist in indexes table
+    print(f"Warning: Could not remove index from metadata: {e}")
+
+con.commit()
+con.close()
+con_init.close()