How to store conversations in sql database for Cleverbot type system?

[FluffyPancakes]

I am working on a project similar to Cleverbot (a chatbot). It will store user input and quickly match it with a response that another user already gave for that input.

What would be the proper way to store the conversation in a database? Just as a table with a bunch of individual records of sentences? (with key>value type pairs?)... or is that the wrong way to do it... especially if the db gets very large? Since each input could have more than one response, how should that be handled, just as a multivalued?

Should it be broken up into different sections somehow? What should I do if I want it broken up based on current conversation context? (as in: have software recognize that the user is discussing kittens, and only pull the responses that were in kitten-related responses)

Also, I'd like each individual interaction have the full conversation (increment) tracked and a session id stored to track individual conversations to help with improving the system. Should this part be in a different table of the database?

I'm just trying to get some initial input/ideas... so I can get started in the right direction. Database planning isn't my specialty...so anything helps.

Should it simply be like this?
(Use the user's input to query the left side and then select text to use from the right?)
(Input Column) Hi, how are you? >>> (Matched Output Column) I'm fine, you?