Jimako’s Blog

Sometimes, the pressures at work distract us from the other parts of our lives that are important but, well, never seem to be urgent. It struck me over the weekend that I had spent an incredible amount of time either at work, or thinking about work, over the past few months. It’s one of those traps that are always there, ready to spring, and I seem to get lured into it time and time again.

This time, the realisation came to me during a meeting that we were holding at our home. It was a meeting of the Social Committee of the Lodge that I am a member of, and we had twenty or so people attend, comprised of members of the lodge and some of their partners. The Social Committee is an opportunity for our women folk, who are not able to participate in the ritual of the Craft, to take an active part in the charitable and social work that we do, and to meet the other members of the Lodge and their families.

After the business part of the meeting was over, and everyone had partaken of the food and drink, a core group of people stayed on for a few hours to catch up and socialise in an informal setting. Maria (my decidedly better half) and a number of the ladies had a great time. Much sparkling wine was consumed by the ladies, a few snifters of various flavours of spirits by the guys, and all of us had a chance to catch up and spin a few stories. It was a really nice time, and we got to talk about a wide variety of things.

As it inevitably does in these circumstances, the conversation turned to why it is that men today are not drawn to Freemasonry. Now, the membership numbers are not in the absolute free fall that they were a decade or so ago, and indeed the latest word is that the membership numbers are pretty much stable. The reality, however, is that there are far fewer members of the Craft today than there were in past generations. The same is true of service organisations like Rotary and Lions. It wasn’t all that long ago that a young man with ambition would have thought it absolutely part of his future to join a local Lodge, but today many (probably most) of them don’t consider the option at all. We all had our theories as to why this was the case, but most of us agreed that one of the reasons is that they are all too busy!

Today, the 40 hour week is a distant memory for most working people. Sure, you may only be in the office for 37.5 hours, but when you add in the ever-increasing commute and the inevitable “just one small thing” that you take home with you, or the research or background reading that you do at home, I think that fifty hours is closer to the average work week. Then there are all the structured activities that we do for the kids — every night, someone has to drive one child or another to a music or dance or drama lesson, a sport event, a school function or some other event that, somehow, has become a totally necessary part of life today (even though we all grew up without any of them).

So in the hustle and bustle of everyday life, we lack that moment of stillness that is necessary to realise that something might be missing.

For anyone reading this that is not a Freemason, let me give you a little bit of information. In the three levels, or degrees, of the Craft, a lesson is taught using a combination of role-playing and oral recitation. The lessons are on many levels, and the whole point of the lessons is to have each individual interpret them in a way that will benefit himself, will help him to become a better person in all aspects of his life. There is no masonic dogma — none at all. The whole point is for you to use your own mind and intellect to better yourself, not to adopt the ideas of someone else.

All of which is necessary to understand that when I talk about “the lessons” of each degree, I am talking about ONE way that they can be interpreted, and by definition anything that I say is going to be coloured by my own personality and perception. Neither am I divulging any secrets here — there are surprisingly few secrets in Freemasonry. So, with that out of the way, here’s what the three degrees teach. Or perhaps I should say here’s what I learnt.

In the first degree, you are taught that you are here for a reason, and that you, yourself, are going to discern that reason. You are taught that you are inextricably connected to the rest of humanity, and that as a member of the family of man you would do well to assist others to the best of your ability, while always being mindful that your charitable activities must not be allowed to impact negatively on the welfare of your family and other responsibilites. Your are taught that you need to be ever industrious, that you are expected to take care of your own needs and the needs of those who depend on you, and not to rely on the charity of others except when there are no alternatives open to you.

The second degree teaches that you also need to work on yourself. You need to balance your time between working at your profession, craft or employment, and working on improving your mind, your body and your spirit. Without doing this, your ability to contribute to the world is going to be limited, both to the world at large and to those nearest and dearest to you.

Finally, the third degree brings you face to face with the fact of your own mortality, emphasising that you don’t have eternity to do what you want to do — you may not even have tomorrow — so do what you need to do now, and be ever mindful of your priorities.

I suspect by now you know where I am going with this. I seem to be regressing time and again to the first degree, being industrious, giving freely of my time and energy to try to benefit all those around me, both at work and at home. But I seem to lose track of the time, to forget (or ignore) the need all living things have to improve themselves, to grow, to realise their potential. And I’m not getting any younger.

So with this posting, I reaffirm my commitment to strike a balance, to work daily on improving myself in some small way, to take the time out from my schedule to THINK about what I am doing and where I am going.

I’m sure I’ll slip again. But that’s OK. I hope it will be longer before the next time I slip back into old habits, and that I’ll pick up on it in a more timely manner when I do so.

I just read an interesting article over on Java Lobby by Dennis Forbes titled Out of Bounds : Avoiding Career Protection Faults.

The article really rang some bells in my mind. I didn’t really identify with the concerns about job and career security — I guess that I have been fortunate to work with development groups that are fairly self-confident, and managed by people who can see past the little bits of political posturing that does take place. No, what caught my attention was more related to the behaviour of the new generation of programmers when it comes to anything but the newest code and techniques.

I guess I need to be a bit more concrete. A very good friend of mine, who will remain nameless to protect the innocent, was involved in a web application (yeah, I know, another one). They were using Hibernate to provide an “object” view of the database.

Now, before everyone jumps all over me, let me state quite clearly that I like Hibernate. I like it a lot. This is not a criticism of Hibernate. Are we all clear on that? OK, moving right along…

Recently, they needed to implement a report. Nothing fancy, just your usual run-of-the-mill business report, pulling a few thousand line items and doing some basic totalling and so on. It came back from the dev team, with a note that it now works, so the story is complete, but probably needs to be optimised.

Boy does it need to be optimised. It takes over 4 hours to produce the report.

Now, these are not dumb developers — nothing could be further from the truth. They are very bright, and they write first-class code. But they are young and idealistic. I’m going to sound like my father for saying this, but the reality is that they haven’t had enough real-world production experience to make the right decisions on gut instinct. Therefore, in the absence of that, they always apply the pearls of wisdom gathered from the latest “best practices” guru or article without filtering it through some basic sanity and appropriateness checks.

Let’s get back to the report in question as a case in point. There are two reasons that the report was running so slowly. The first is a general reluctance to use the database for what it does so well — querying data. Instead, they use Hibernate to get object graphs. And while Hibernate is pretty good at doing sensible things with lazy loading, there is a limit to how well it can optimise this sort of thing and it seems, more often than not in these sorts of scenarios, that it is pulling more data than it needs to out of the database. Quite frankly, I think that creating reports, or lists of items to display in a list view, is generally better done using a simple SQL query that returns just an ID with a the set of columns actually required for displaying the list or report. Hibernate even has a mechanism for doing essentially exactly this, using report queries and HQL, so I am prepared to accept that as a viable alternative, but I would prefer SQL because, quite frankly, it is better understood.

Hibernate is actually pretty well documented, especially for an open-source project. Indeed, it is pretty well documented, period. Many commercial packages could learn a thing or two from Hibernate’s documentation. But compared to the huge body of knowledge that exists about SQL, and the decades of real-world experience, frankly, it just doesn’t cut it. Not unless you happen to have a Hibernate guru on hand.

So, I think that using tools such as Hibernate, and refusing to entertain using raw SQL under any circumstances, is part of the problem, but only a very small part. I doubt you could make Hibernate take 4 hours to do the report even if you were trying very hard. No, that is not where I think the problem lies.

We can get closer to the problem by stepping back a little. The reason that they can’t just run a query to get the report data is that the data is not stored, but calculated on demand. The system stores transactional data, and all balances are calculated as required using a bunch of (often nested) calculators that walk the database. So if I want a balance, I walk all the transactions that affect the balance (and there are many types of transactions in several tables with various dependencies) and do a calculation, often quite complex.

From a coding perspective, it’s a one-line call to a calculator method to get the data I want, so it looks quite elegant, and the calculators are tested separately and I know that they are correct.

The calculators do some basic filtering of the transactions that they process, but they still need to read a lot of them, and sometimes they end up using some lazy fetching of related data. It’s just the way the data mapping is done, because there are conflicting requirements for different functions in the system. The end result is that doing a calculation is quite expensive, which is not a problem when you are doing just a single calculation.

But what if I want to get month-end balances for the past year? Simple, just loop though the required dates, pass them to the calculator, and get back the balance on that date. It’s really easy for the calculator to just stop processing transactions when it gets to a particular date.

And if I need DAILY balances? Do you see where this is going?

Inside what looks to the developer like a simple loop, there is a huge amount of database activity going on, and done in such a way that the database has no opportunity to do anything but act as a dumb file store. That is what is bringing the database (and the system) to its knees when this report is run.

Now, at this time, gentle reader, you are probably thinking to yourself: why was the database structured that way in the first place? Well, do you remember in school, when you were told not to store something in the database if it can be calculated? Well, that’s what blindly following that advice ultimately leads to.

Now, I am not advocating that we forget about things like normalisation and removal of redundancy. But all general rules need a context. Just because something can be calculated does not mean that it should never, under any circumstances, be stored.

Take this calculated balance as a case in point. Calculating it is expensive, so storing it should at least be considered, and implemented if the time taken to recalculate it makes it impractical to use recalculation whenever it is needed. Even more importantly, some data items, even if they can be calculated, have a distinct “point-in-time” value and therefore need to be stored regardless of the time it takes to recalculate them.

Let me explain that, because it is important.

Let’s say that a calculation involves a set of input values, transactions, exchange rates, interest rates, taxation rates… you get the idea. It’s more than just the initial and transactional data. Calculating a value means you need to get, for each transaction, the applicable rates that were in effect when that transaction occurred, so you need to keep historical data for each of them. OK, that much is obvious, and there is a clear requirement to store that history if you are going to recalculate as required.

What most people forget, however, is that there is another component to the calculation that can change over time — the code of the calculation itself. If there is a different way to calculate sales tax, for example, or a new type of tax is introduced, or simply a business rule changes, then the calculation logic itself will change and it will generate different results for the same input data.

So if you want to recalculate an invoice amount for a past date, you better have a copy of the correct version of the calculator code around too, and you better have an infrastructure in the code to handle identifying and instantiating the correct version of the calculator. And it’s even more complex than that, because if the output of a given calculation feeds into the next period’s data, then you need to identify, instantiate and use the correct version of the calculation logic for each period as you are looping forward.

You’d better be able to handle this correctly, because if you don’t, your client-facing staff will see one figure on the screen while the customer will have a different figure on the invoice. Trust me when I say that this is not what you want.

Whenever a figure has a meaning at a point in time, it is a data point all by itself. In my mind, it is a no-brainer: it needs to be stored. In a product order line item, for example, you don’t store the extended price, because you can always calculate it as unit price times number of units.

But you do store the unit price and description, even if you could always look them up from the products table. Why? Because they can change, and the line item is a point-in-time data value. In this case, we are shielding the point-in-time data value from changes in the data inputs. We are not concerned about the extended price, because the point-in-time data value’s data inputs (ie the unit price and number of units) are captured at that point in time, and we do not foresee (and will not support) any changes to the trivial calculation logic. If the calculation logic were ever to change, then I would see no real alternative but to store the extended price in the line item.

Could someone have pointed this out earlier? Yes. Did anyone do so? Yes. Did anyone listen? Unfortunately, no.

You see, that was “old world” thinking. We have a calculator! Why would we want to store the data value when we can always calculate it?

This post is long enough. If anyone ever reads it, I fully expect to be flamed. Just before you hit that comment button, however, please take the time to understand the point I am trying to make. I am not trying to discount modern best practices, or the tools that are currently in vogue. I actually pride myself as being pretty good at picking up new ideas and technology, and leading rather than following in their adoption. I am simply pointing out that, in my opinion, we need to apply a real-world filter over all the stuff that we are constantly being bombarded with, and realise that there are no absolutes — no rule can be applied blindly without some thought.

And sometimes, just sometimes, we older folks might know a thing or two that can be useful.