How can I calculate the average gas cost per a transaction on RSK?

Question

I want to calculate an average gas fee paid for all transactions on the RSK within the last three months. I tried to query the RSK blockchain using the Web3.js library. To get transaction data for just a single block height, I had to do:

const txsPerBlock = await web3.getBlockTransactionCount(block.height);
const txs = await Promise.all(
    [...Array(txsPerBlock).keys()].map(
        (i) => web3.eth.getTransactionFromBlock(block.height, i))
);

And then to calculate the average gas fee:

const averageGasFee = txs.reduce(
    (p, c) => p + Number(c.gasPrice) * c.gas,
    0
) / txs.length;

However, within 3 months there were about 230,000 blocks on RSK including about 3 transactions per block. So I had to poll about 600,000 transactions that would take forever to complete. I waited for an hour and then canceled the script. Is there a better to query the RSK blockchain and calculate the average transaction gas fee over such a large number of blocks and transactions?

Answer 1

You can use the getBlock() method (docs) that is able to return all transactions in the block at once if you pass true as the second param (returnTransactionObjects).

const block = await web3.eth.getBlock(blockNumber, true);
const averageGasFee = block.transactions.reduce(
    (p, c) => p + Number(c.gasPrice) * c.gas,
    0
) / block.transactions.length;

This results in "only" 230k requests instead the previous 600k.

Answer 2

It's much easier to accomplish this using Covalent. You can calculate the desired gas fees by performing a single PostgreSQL query:

SELECT AVG(t.gas_spent * t.gas_price) / 10^18     AS gas_paid
FROM chain_rsk_mainnet.block_transactions t
WHERE
    t.signed_at > (NOW() - INTERVAL '3 month')
    AND t.signed_at <= NOW()
;

The result of this query is 0.000009922904625 (RBTC), and it took only 4.2 seconds to execute/ obtain the result.