You are developing a real-time fraud detection system using Snowpark and deploying it as a Streamlit application connected to Snowflake. The system ingests transaction data continuously and applies a pre-trained machine learning model (stored as a binary file in Snowflake's internal stage) to score each transaction for fraud. You need to ensure the model loading process is efficient, and you're aiming to optimize performance by only loading the model once when the application starts, not for every single transaction. Which combination of approaches will BEST achieve this in a reliable and efficient manner, considering the Streamlit application's lifecycle and potential concurrency issues?
Correct Answer: A
Option A is the best approach. 'st.cache_data' is the recommended way to cache data in Streamlit, including large objects like machine learning models. It automatically handles concurrency and ensures the model is only loaded once per Streamlit application instance. Because it's Streamlit's mechanism, it plays well with the Streamlit lifecycle. It is not required to use a Pandas DataFrame like option C suggests. Python global variables (B) are not suitable for web apps due to concurrency issues. While threading locks (D) could work, they add complexity and are generally less desirable than using Streamlit's caching mechanism. The model loading can be cached without a try-except block to set the Snowflake session as a singleton (E).