Where is the log of transactions stored?

Question

I have created a simple smart contract using geth and I am able to run it successfully without any issues.

The code I have used is:

pragma solidity ^0.4.13;

contract Simple {
  function arithmetics(uint _a, uint _b) returns (uint o_sum, uint o_product) {
    o_sum = _a + _b;
    o_product = _a * _b;
  }

  function multiply(uint _a, uint _b) returns (uint) {
    return _a * _b;
  }
}

I am able to run it using the command: simple.multiply.call(10,20)

The logs of all these transactions should be stored somewhere in the blockchain. Where are they stored? How can I access them?

Answer 1

You're using the method call which, as opposed to a transaction, is not reflected on the blockchain. The function you're calling is not altering blockchain state, thus no change has to be made, thus nothing is stored, thus nothing is communicated to other nodes, thus you don't need to pay anything.

This method is only called in your own node, and your node is the one computing it. There is no logs for your calls since they're only processed locally.

However, it is good practice to tag your function multiply with the label constant or view so that you explicitly tell users that this function is read only.