Out of the box, CA ERwin Data Modeler has a default datatype of char(18). This default is used when you create an attribute or column in a data model and don’t specifically assign a datatype to that attribute.
I don’t know this for a fact, but I’m guessing the developers of ERwin chose this odd length so it would stand out as being a bit odd, reminding modelers to choose a “real” datatype and length at some point. You can see in the figure below that I’ve added an attribute named test to the MOVIE entity, but did not assign a datatype, so ERwin gave it the default datatype of char(18).
However, one the problems with this is that it is still not odd enough. One of the tips I picked up while speaking at the BeNeLux Modeling User Group was that you can set the default datatype in ERwin to something especially funky, char(-1). That datatype is certain to:
- Stand out in both the data model diagram and any DDL
- Not generate valid DDL
- Fail any DDL testing
- Make a DBA really mad
- Motivate database designers to set real datatypes
Sounds to me like the perfect datatype for being a default.
Defaults in ERwin are model-specific, meaning that you set them on a .erwin file basis. To do this in ERwin 7.3, you must first open your model, then go to MODEL, MODEL PROPERTIES:
This will bring up the properties dialog. Choose the DEFAULTS tab.
In the Default datatype section above, you can set the default datatype to char(-1) or whatever makes sense for you project. I’ve seen some people make a good guess at the most generic datatype, something like varchar(50), but I prefer to assign an oddball datatype so that I can find these “unassigned” attributes and columns easily. Note that you can also set separate defaults for the logical and physical models. Since I’m choosing to set the default to an invalid default, I set them the same.
Having said this, I rarely create attributes manually. I usually create attributes via the domain approach, where domains have a “best guess” standard datatype that makes sense for the type of data contained in them. For instance, a domain for email address would normally be varchar(254) in a model, since that is the Internet standard for email addresses. However, attributes do get created without a domain all the time, so it makes sense to have a default datatype that meets your needs.
Having set my default datatype in my model to char(-1), when I create a new attribute and don’t assign a datatype it will be set to the default as shown in the MOVIE entity below:
The key to using an invalid datatype is to ensure that you’ve circled back and set them all to a real datatypes and lengths before you derive a new model from them, generated DDL, or compared to a database.
You can use a report or the ERwin Query Tool to find all the attributes that have this datatype:
More on the ERwin Query Tool in another blog post soon.
If you have a Twitter account you can post your question (in 140 characters or less) with the #SQLHelp hashtag and most likely someone will jump in to answer the question.
Thousands of SQL Server experts (many who do not dress as Tina Turner) want you to be a SQL Server Success, so they monitor this hashtag to answer your question or give you tips on how to address an issue. Of course the format of Twitter means that you probably won’t want to ask about the meaning of life (A:42) or big complex issues, but even then there’s probably a blog post that someone can point you to.
Some recent examples of questions and answers to this tag:
I’ve made use of this “service” on Twitter a few times when I needed help with a physical design consideration. It’s great that the SQL Community is willing to help like this. Perhaps we should be posting questions under hashtags like #ERwinHelp and #ERSStudioHelp, too.
In addition to Buck and Lil Buck, Computer Engineer Barbie attended the PASS WIT Luncheon with me.
I spent last week in Seattle attending the Professional Association for SQL Server (PASS) Summit (as if you could not tell from my tweet stream). Like most successful conferences, there was more to it than a bazillion sessions. There were so many events: vendor events, unofficial events, pre-cons, post-cons, impromptu events and more. I feel as if I couldn’t stretch myself far enough to take advantage of all them. Did I mention there were sessions, too?
We arrived in Seattle on Friday so that we could do our obligatory cross-border shopping at our favourite not-available-in-Canada retailers: Fry’s Electronics, Kohl’s, Target and Trader Joes. It is my goal to shop at every Fry’s in the US; so far I have tackled more than half of them. We didn’t buy much there, but its like visiting a gadget museum. Geekiness for the win. We spent time on Saturday shopping as well. We were doing our best to help stimulate the US economy.
We also spent time visiting with friends, including Yanni Robel, John Robel, Corey Smith and Eva Smith. We know Yanni and John from the SQLCruise. We know Corey and Eva from numerous DAMA events. But we built these friendships via the conversations we have via Twitter and Facebook.
On Sunday I participated in Freecon, a special event for bloggers and social media celebrities from the SQL Server world. This event, hosted by Brent Ozar, covered topics such as developing content, dealing with plagiarism, monetizing writing, and consulting skills. I’d love to see this event develop into a writers’ guild for those of us putting content out there.
Monday was the opening session for the PASS Summit. There was a Quiz Bowl “panel”, where SQL “elites” played a Jeopardy-like trivia game. I’d love to see Enterprise Data World (EDW) offer a similar opening session event.
I’m not going to list all the sessions I attended, but I wanted to point out that there were several sessions that focused on data architecture topics. My own session on “Starting with More than a Blank Page” focused on how to best adopt data model patterns/industry standard data models. A session by Louis Davidson covered Intro to Database Design. Normalization is a tough topic to cover in just over an hour and I thought he did a great job helping people visualize why the normal forms exist.
It took me a while, but I managed to meet up with Neil Buchwalter, Product Manager of CA ERwin Data Modeler. CA is a founding organization of PASS and Neil has a spot on the PASS Board.
Wednesday was SQLKilt day. What a hoot. There were many attendees dressed in kilts, mostly just because they could, but also in honour of the Women in IT. In fact, Jen McCown of MidnightDBA fame produced t-shirts to link the kilts to WIT. That’s Sean McCown there, sporting a kilt and the t-shirt that asks “What are you doing” for women in IT.
Did I mention that several people found new jobs/gigs right at the conference? There was a job board in the exhibits area, but most of these “connections” happened ad hoc during the lunches, coffee breaks and informal get-togethers that surrounded the event. As I tweeted, #Network to #Getwork.
Network to Getwork
As I have blogged before, one of the best things about attending SQLPASS was that Rob and I knew hundreds of the attendees, even though it was my first time attending this event. The connections we made on Twitter, Facebook and LinkedIn prior to the conference paid off in spades for us during the event. Sure, I was a first timer, but it wasn’t a bunch of first conversations. For me, this is the real power of tying together virtual and in-person events.
I’m bringing home a DVD of the SQL Server new version codenamed “Denali”. I’m looking forward to getting it installed, then moving on to all the evaluation licenses I received for third party tools.
I will definitely be back for next year’s PASS Summit, again in Seattle in October 2011 and SQLRally 2011, located in Orlando in May. I want to continue learning about SQL Server and making connections with industry leaders in this space.
In addition to today being SQLPASS Women in Technology Day, it is also a special Internet meme called Picture Me In Computing (picturemeincomputing.org) day.
This special 24 hour event focuses on encouraging girls and young women to enter the computer field, which is the reason why I have been active in the Women in Technology field in PASS and CIPS.
While we in the IT field still struggle with gender-related issues in the workplace, I believe IT is one of the most rewarding professions that a young woman could consider.
So I’ll be tweeting pictures, videos, and comments from #sqlpass of men and women who support #WIT . And please note how much Barbie looks like me!
While I’m doing that, you can show your support by retweetingand posting your own good content. To participate in today’s “Internet flash mob” for women in computing by doing thses things:
* Upload a picture of yourself with technology or with CE Barbie® (or her image) to Picasa
* Cryptically set your status on Twitter, Facebook and Myspace to the last place you saw CE Barbie® (“I saw her on the UO Campus!”)
* Record a video blog and upload it to YouTube with the tag “picmecomp”
* Tag all of your tweets for the day with #picmecomp
* Blog about picmecomp and what it means to you
Finally, it looks like this event is somewhat affiliated with Google and Mattel. I’m happy they are supporting this important cause, but we at the PASS Summit may want to keep our participation in this a bit separate from the official Microsoft events. Isn’t it great, though, that these technology and commercial giants are supporting women in IT on the same day?
Recently I was honoured to be an invited panellist at the ComputerWorld IT Leadership Awards Gala in Toronto on 26 October 2010. I was invited as an IT/Social Media Thought Leader by IBM to talk about how IT can best support successful businesses, especially mid-sized businesses. The panel was moderated by Shane Schick, Editor-in-chief of ComputerWorld Canada.
I was also honoured to be designated as a an IT Influencer based on the work I do promoting the profession and engaging in community and social networks. I hope to write more about the analysis that was done to identify the top 3 IT Influencers in Canada.
I was happy to be a part of these awards, which recognize IT leadership in many categories, including traditional leadership positions such as IT Manager and CIO, but also recognized a Rookie of the Year, IT Mentor and Women in Technology Mentor of the year. It’s important that our profession recognize the people who are making a difference locally in their own organizations and across the profession.
On Saturday, 20 November 2010 I’ll be speaking at SQLSaturday 59 in New York City on Database Design Contentious Issues. SQLSaturdays are free to attend, so if you are in the NYC area you can attend all the great sessions, including mine, for no extra charge. So breakfast, lunch, prizes and great professional development all provided by sponsors and volunteers.
Robert Pearl interviewed me as a #SQLSaturday59 event speaker.
KL: Database Design Contentious Issues is a presentation I’ve been doing for almost 15 years. The content changes, but the format is the same. I give a 60 second overview of a contentious issue and then everyone votes at the front of the room about what is the “right” answer. Then we debate varying points of view for that issue. So it’s like all those Internet flame wars, but in person, where you get to see the troll you are debating with instead of his avatar. I’ve even had people bring protest signs this. It is a blast.
RP: What is your motto?
KL: Love Your Data ♥…
RP: Who can disagree? Thanks, Karen for your time and answers! We truly look forward to meeting you and seeing you there!
Read the full interview for insight into how these events tend towards the “fun” side.
ProTip: many SQLSaturday attendees negotiate a day off during the week in exchange for attending training on the weekend. Your boss owes you for finding FREE training, right? Imagine yourself lounging around on a weekday just because you attended a fun, prize-filled, crazy event on Saturday. Imagine the holiday shopping you could get done instead of cramming it into the weekend. Just sayin’.
Did you attend my presentation at SQLSaturday #59?
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