Addition/Deletion records based on method argument I have one method for addition and deletion of the account records. It has method argument based on which addition or deletion happens. 

Below is method 

char ADD = 'Y';
char DELETE = 'N';
private void updateAccountDtls(AccountDtlsDTO accountDtlsDTO, char addOrDeleteRecord){
    if (ADD == addOrDeleteRecord) {
        //account addition related processing
    }
    else if (DELETE == addOrDeleteRecord) {
        //account deletion related processing
    }
}


which is consumed in switch like below

switch (action) {
        case SET:
            updateAccountDtls(accountDtlsDTO,ADD);
            break;
        case RESET:
             updateAccountDtls(accountDtlsDTO,DELETE);
            break;
        }


from performace perspective is this good practice to use character instaed of string for Yes/No?
Performance wise you're not going to notice the difference.

There is a far better solution available to you though. That is to have 2 separate methods altogether.

You already have a switch statement before calling the method in which you know that it will be a delete or an add. This makes it really easy to just call the right method.

Having separate methods that each do a specific thing makes the code easier to read and maintain later on.