What's the cheapest way to store a large amount of data into a smart contract?

Question

I'm working on a smart contract in which we need to store some addresses along with their pending rewards periodically,

so the most first approach is to have a mapping of addresses to an int, like below:

mapping(address => uint256) pendingRewards;

The problem is that when you want to set/update all these data at once, it will cost a lot of gas to loop through the mapping and update them all.

so in other words, let's say I have a table of addresses and pending rewards, consider it's a huge huge table, what would be the best practice to set/update these data into a smart contract?

!! MerkleTree would not solve the problem because we can't retrieve pendingReward with the address as the key from that.

Answer 1

The problem is that when you want to set/update all these data at once, it will cost a lot of gas to loop through the mapping and update them all.

You need to design your smart contract logic in a way that there is no need to do this kind of batch update operations.

This is quite well understood problem. There are multiple well-known decentralised projects like Uniswap, Sushi, Balancer which you can study to understand how it is done.