Add excercise fixes

Author: MDUYN

…ss_database_system/.docs/instructions.md …base_system/.docs/simple_instructions.mdbenchmark/advanced/multi_class_database_system/.docs/instructions.md renamed to benchmark/advanced/multi_class_database_system/.docs/simple_instructions.md benchmark/advanced/multi_class_database_system/.docs/instructions.md renamed to benchmark/advanced/multi_class_database_system/.docs/simple_instructions.md

@@ -1,20 +1,42 @@
 # Database System with Existing Classes
 
+
+Implement a complete C++ database abstraction layer that internally uses multiple private classes to manage connections, optimize queries, and handle transactions. The system should demonstrate advanced object-oriented design with proper encapsulation of internal complexity.
+
+Implement the following function:
+
+```cpp
+std::string execute_database_operation(const std::string& operation_type,
+                                     const std::string& query,
+                                     const std::map<std::string, std::string>& parameters);
+```
+
+- **Input**: Operation type, SQL query/command, and optional parameters
+- **Output**: Formatted result as JSON string or status message
+- **Process Flow**: Connection pooling → Query optimization → Transaction management → Result formatting
+
+Please retrieve the following files from azure search:
+
+- cache_manager.h
+- cache_manager.cpp
+- connection_pool.h
+- connection_pool.cpp
+- query_optimizer.h
+- query_optimizer.cpp
+- result_processor.h
+- result_processor.cpp
+- transaction_manager.h
+- transaction_manager.cpp
+
 You have several C++ classes already implemented for database operations:
 - `ConnectionPoolManager` (connection_pool.h/cpp) - manages database connections
-- `QueryOptimizer` (query_optimizer.h/cpp) - optimizes and processes SQL queries  
+- `QueryOptimizer` (query_optimizer.h/cpp) - optimizes and processes SQL queries
 - `TransactionManager` (transaction_manager.h/cpp) - handles transactions
 - `ResultProcessor` (result_processor.h/cpp) - formats query results
 - `CacheManager` (cache_manager.h/cpp) - manages query caching
 
 **Your task:** Write an `execute_database_operation` function that coordinates these classes to handle database operations.
 
-## Function to implement:
-```cpp
-std::string execute_database_operation(const std::string& operation_type,
-                                     const std::string& query,
-                                     const std::map<std::string, std::string>& parameters);
-```
 
 ## Key points:
 - Initialize all manager classes and coordinate their interactions
@@ -32,17 +54,3 @@ std::string execute_database_operation(const std::string& operation_type,
 - `execute_database_operation("TRANSACTION", "BEGIN", {})` should start a transaction
 
 **Hint:** Create instances of all manager classes, then coordinate them based on operation type.
-
-
-## Re-using Components and Existing Code
-Please reuse the following files:
-- cache_manager.h
-- cache_manager.cpp 
-- connection_pool.h 
-- connection_pool.cpp 
-- query_optimizer.h
-- query_optimizer.cpp
-- result_processor.h
-- result_processor.cpp
-- transaction_manager.h
-- transaction_manager.cpp