[Python] How to store and load the state from an external database

Currently, I'm using checkpointer to store the LangGraph's state like below:

order_information_subagent = create_react_agent(
llm,
tools=OrderToolset.get_all_tools(),
name="order_information_subagent",
prompt=OrderAgentPrompts.order_subagent_prompt,
state_schema=State,
checkpointer=checkpointer,
store=in_memory_store
)


but this only helps in persisting the state of the current execution. How do we store and load the historic-state data from an external database like PostgreSQL or MongoDB?

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