bank | Statsd and Metricsd frontend for UDP packets aggregation | Networking library

Advice/opinion

A database is for persistent storage of numbers and text.

An app is for computing and deciding things.

That is, the complex business logic you describe may be more appropriately encoded in Java (or other app language). Meanwhile, the breakpoints, etc for interest rates should be stored in the database.

Phrased differently: "Business logic" belongs in the app, not the database. (There is, of course, a gray lines between them. For example, SQL is excellent at summing up all the data in a table; so, I would do that in SQL, not Java.)

Decimal

Banks have picky rules that may not be the same as what DECIMAL or DOUBLE provide -- in Java or MySQL or _any other computer language. Be careful of the rules that may be required. In particular, DECIMAL(10, 4) is unlikely to be adequate in your application. On the other hand, apy DECIMAL(4, 2) may be adequate if that is what is presented to the customer. But, again, beware of rounding rules when generating that number. You may be forced to enter that number manually.

Be aware of the difference in rounding characteristics between DECIMAL and DOUBLE.

Answer

If you choose to implement an algorithm in the database, then see CREATE STORED PROCEDURE and CREATE FUNCTION.

Stored Procs can be used to encapsulate a set of SQL statements. It can receive and send strings and numbers, but not arrays. It is capable of reading tables (hence "arrays" of a sort.)

Functions can be called anywhere an expression can occur. It can receive some numbers/strings and produce one number or string.

Array

I'm not clear on what is needed, but I envision a table of a few rows or a few dozen rows with each row saying "for values up to $xxx, use y.yy% interest rate".

Stored Procs have "cursors" and "loops" but they are clumsy; the app language is likely to have better code.

In your case, I would say it is ok because I guess that if Account.balance < Transaction.amount you don't really want to go forward with the transaction. So you must at some point get the needed data from the AccountService, there is no way around that.

If you just wanted o trigger some side-effect task (like sending an email or something) you could rely on an event-based approach on which TransactionService would publish an event and a hypothetical NotificationsService would react to it at some point in time and do its thing.

You can check the DOM attribute select.options.selectedIndex to check if the elements are selected. let button = document.getElementById('btn'); let deadline = document.getElementById("deadline"); let desiredPD = document.getElementById("Desired_payment_date"); let bankTD = document.getElementById("Bank_transfer_destination"); let myCkeck = document.getElementById("myCheck"); let accountT = document.getElementById("AccountTransfer"); /* In this solution, when the button is clicked, control is done. */ button.addEventListener('click', function(event) { if(isValid()){ alert("done"); } else{ alert("failed"); } }); /* This method returns true if validation is successful. */ function isValid() { if (document.getElementById("tab-1").checked) { let result = (deadline.selectedIndex != 0) ? true : false; result &= (deadline.selectedIndex != 0) ? true : false; result &= (desiredPD.selectedIndex != 0) ? true : false; result &= (bankTD.selectedIndex != 0) ? true : false; result &= (myCkeck.selectedIndex != 0) ? true : false; return result; } else if (document.getElementById("tab-2").checked) { return (accountT.selectedIndex != 0) ? true : false; } else return false; } table, tr, th,td{ border: 2px solid #dfd7ca; } Bank transfer Account transfer

deadline 20 30

I got a successful solution by decreasing the final time (max=0.04 for successful solution) and rearranging the equations to avoid a possible divide-by-zero:

Your problem is that your code don't uses Async all the way up.

Your Account class has the method Open, Close, Balance and Transaction and you use a AsyncReplyChannel but you use PostAndReply to send the message. This means: You send a message to the MailboxProcessor with a channel to reply. But, at this point, the method waits Synchronously to finish.

Even with Async.Parallel and multiple threads it can mean a lot of threads lock themsels. If you change all your Methods to use PostAndAsyncReply then your problem goes away.

There are two other performance optimization that can speed up performance, but are not critical in your example.

1. Calling the Length of a list is bad. To calculate the length of a list, you must go through the whole list. You only use this in Transaction to print the length, but consider if the transaction list becomes longer. You alway must go through the whole list, whenever you add a transaction. This will be O(N) of your transaction list.

2. The same goes for calling (List.sum). You have to calculate the current Balance whenever you call Balance. Also O(N).

As you have a MailboxProcessor, you also could calculate those two values instead of completly recalculating those values again and again.Thus, they become O(1) operations.

On top, i would change the Open, Close and Transaction messages to return nothing, as in my Opinion, it doesn't make sense that they return anything. Your examples even makes me confused of what the bool return values even mean.

In the Close message you return state.Opened before you set it to false. Why?

In the Open message you return the negated state.Opened. How you use it later it just looks wrong.

If there is more meaning behind the bool please make a distinct Discriminated Union out of it, that describes the purpose of what it returns.

You used an option throughout your code, i removed it, as i don't see any purpose of it.

Anyway, here is a full example, of how i would write your code that don't have the speed problems.

You need to write:

Short answer is that there's no way for you to do this using Account Tokens.

Currently, Account Tokens don't support the documents hash so passing in documents.bank_account_ownership_verification won't work. Your only option is to pass in documents.bank_account_ownership_verification (see apiref) when you update the Account directly (not through a token).

Because you are using vw in certain places, this unit takes a fixed percentage of browser size of 50vw mean 500px of 1000px screen and 50px of 100px screen, I would suggest to use rem instead also, you can go a bit advanced and use css clamp() to fix width of multiple screen at once.