A few weeks ago I got really tired of all the spam that I was getting (on the order of 100s a day), and I moved my email to Gmail my domains. Almost immediately the amount of spam that I get dropped to 1 - 3 a day. Obviously, I wanted to connect to it via Outlook, and keep the familiar user interface and offline features.

It was no problem setting this up, but I find that for the past week and a half I have no opened Outlook. I am using Gmail for everything, and I am very happy about it, too.

I have posted in the past about NHibernate's cascade being one of the places that require careful attention. But I run into an issue with it yesterday.

The issue was that we had a typical parent-children scenario, but the requirement changed and we had to support orphans. That is, children without a parent. This isn't that big of a deal, after all, and I told Imperial to just change the cascade from all-delete-orphan to all, and forgot about it.

I was called a few minutes afterward, and saw that the change didn't have the desired effect. The scenario that we were working on was deleting the parent, where the child needed to remain behind (will null foreign key, of course). Now, I was being stupid, and I started debugging into NHibernate to figure out what was the cause of this "bug". Ten minutes later (took a while to find where exactly this was happening), I had an "Oh, I am so dumb" moment.

So, to save myself from future embarrassment, let me try to articulate what it means:

Here is what each cascade option means:

• none - do not do any cascades, let the users handles them by themselves.
• save-update - when the object is saved/updated, check the associations and save/update any object that require it (including save/update the associations in many-to-many scenario).
• delete - when the object is deleted, delete all the objects in the association.
• delete-orphan - when the object is deleted, delete all the objects in the association. In addition to that, when an object is removed from the association and not associated with another object (orphaned), also delete it.
• all - when an object is save/update/delete, check the associations and save/update/delete all the objects found.
• all-delete-orphan - when an object is save/update/delete, check the associations and save/update/delete all the objects found. In additional to that, when an object is removed from the association and not associated with another object (orphaned), also delete it.

Fairly simple, isn't it? I have no idea why I managed to forget this. At any rate, my issue was that I set the cascade to all, and then deleted to root object, which naturally deleted all the child objects. Setting it to save-update was what I wanted to do, once I did that, everything went just fine.

If you ever had to work with someone else's database (I assume that yours are perfect), you know that not all databases are nice and clean. In fact, some of them fail to do even simple things, like foreign keys. In some cases, FK is not even possible (think a view over a main frame table that you don't control).

In such cases, almost invariablely, the database slightly corrupts itself. Sometimes it is a programmer error, sometime a failed set of commands without transactions, etc. The end result is that you get an id to another table, but no row that match this id. To say that it is hard to deal with this kind of scenario is an understatement. Even if we are dealing with a nullable FK (which is not always the case), if it has a value, but no matching record, this is a big issue.

Most often, this lead to an attempt to "clean up the data", but this usually lead to finding even more issues, and in many cases there is a big fear that this will damage business critical data. The developers are then left to fend themselves against the unruly database (and the damaged relational model is weaping at the corner).

In NHibernate 1.2, a new attribute was introduced to help solve this issue, this is not-found="ignore", which instruct NHibernate to treat non existing FK not as errors (as is the default), but as nulls. Here is a simple example:

The nice thing about this feature is that if you save this object into the database, NHibernate will update the column to NULL, helping to restore the database to a sane state.

Dennis is talking about the shutdown button issue, and bring some new insight into it:

Is it really that surprizing that a lot of people have a say in this critical feature? Maybe not. I agree that this is a highly visible feature, and that it has ties to all sort of surpising places (the kernel for one, the messaging system to inform other applications - including the hot boot support, etc).

The problem that most of us have with this is not the complexity of the ties to this feature, I think that if someone sat down and thought about all the places that this feature would touch, they would be amazed. I spend half a minute on this and I can think of a lot of issues, and I have little interest in Windows Internals.

The problem is that someone spent a year actively working on the menu. And the way it was managed. A quick calculation shows that 3.5 man-months were wasted just in meetings about this feature. 3.5 months. 

There is also the huge hassle in getting your dependencies through all the the gate keepers along the way. Let me give you a simple scenario, two teams need a feature from a third team, which is on another branch. Team A discover that it needs a certain feature, and ask team C to implement it. Team C does this, and goes their own merry way. Two months later, Team A gets the change, and they start working on that. Team B, a month later, discovers that there is a bug in their code because of this feature, and request a fix. Two months later, Team C's fix reach them, but four months afterward, Team A disocver that this fix broke their code. Rinse, repeat, weap.

Check this out, this is an update to Remote Desktop that enable some new features, the most important of them is network level authentication.

As someone who sometimes need 5 - 8 computers daily, I rely on RDP quite often, and it is very annoying to put my password every single time.

Great feature!