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Closed 11 years ago.
In 5 days I'm going to ETL interview. It's my first interview on this subject. What question would I be asked? Most likely they will be about MS SQL Server Integration Service.
If possible, provide the answers. =)
If possible, provide the answers. =)
Keep it high-level if you have to, but don't ask a question that couldn't answer yourself.
I agree with Brad that syntax is not important, it's the thought process.
Another idea is to ask them about how they would pack up and move an office. It gives you insight into the same kinds of decisions needed in ETL (prep, actual moving of stuff, and validation), and you might be more comfortable talking about that than the details of SSIS
Think practically. Hand them a printout of a sample file that might need to be imported (possibly simplified to save time). Have them talk about database design, considerations, concerns, possible ways to improve the data. Then bring out a second printout of somehow related and see if they can figure how to validate the one from the other.
Make sure you talk about how much time is available to perform the ETL processes based on business rules and environment.
Require as much pseudo-code as you like, but I personally subscribe to the idea that syntax can be taught cheaply, but learning how to think is a very expensive thing to teach someone; and sometimes it's not even successful.
Also, ask them what standards they would implement if they were to design the optimum layout of the source data. Make sure you consider data distribution beyond your company (if applicable).
Related
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Closed 9 years ago.
I am really new to database and am interested in some high level basic knowledge. I have read this wonderful SO post. I under one is better than another in some cases, but not sure why.
Why is MySQL faster than MongoDB at join operations?
Why does MongoDB scale better in distributed system?
Why is MongoDB faster if I am "just selecting a bunch of tables and putting all the objects together, AKA what most people do in a web app" ?
Thanks a lot!
This question lacks any real research, I mean you say you read that question but either that question has some real problems with the source of its information or...well; anyway:
Why is MySQL faster than MongoDB at join operations?
Because it doesn't have any? MongoDB HAS NO SERVER SIDE JOINS. I am sorry to put that in capitals but I say it soooooo often, I just feel like placing it as the defacto answer for most questions.
Any joins you do are client side. This means they will actually be slower than MySQL, or other SQL techs. The important idea behind doing joins client side is that doing them server-side becomes very hard to scale in huge distributed environments, if not impossible. That is why many big SQL users actually attempt to prevent huge joins and are effectively trying to do in SQL what MongoDB does.
The case for this is scenario dependant of course.
Why does MongoDB scale better in distributed system?
http://docs.mongodb.org/manual/replication/ is very important here and so too is http://docs.mongodb.org/manual/core/sharded-clusters/ and I would recommend reading both carefully and how they scale to data partitions and what not.
Why is MongoDB faster if I am "just selecting a bunch of tables and putting all the objects together, AKA what most people do in a web app" ?
I don't know what you mean by that.
I realise this isn't much of an answer but your question is one of those defacto questions and so I answered with a defacto answer.
Since you are new to databases in general I would personally recommend you go use one...
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Closed 10 years ago.
Which database should I use with node.js? I'm condering MySQL and MONGO DB.
The correct answer is: it depends.
Like many other programming languages node has various adapters for databases. Ture, some are better than others, but they are all changing and evolving so fast that any statement here would be outdated soon. Even if you select one database, you will find at least two or three adapters with different qualities.
In the end it does not really matter what is a good fit for Node, but what is a good fit for your project. Trying to squeeze a relational problem into a NoSQL storage will do you no good.
The node community provides you with lots of possibilities. Take a look at the Node Toolbox to find some solutions for CouchDB, MongoDB, Redis, Database abstraction layers, MySQL, … As always you need a bit of common sense to choose the right module. Look at commit history, how many maintainers, activity, last commit timestamp, issue queue, etc. You will surely find a solution for a database that you are comfortable with.
I personally find it rather overwhelming when I have to learn more than one technology at once. So if you are new to node, I would rather stick to a database you know for your first project.
Every one has different requirements for completion so it really depends on what you are trying to do. Like Joseph said MongoDB and Node.js works really well together but for certain use case, MySQL could probably be a better choice. Also, you might want to considered the database you are the most comfortable with. Personnaly, I would recommand MongoDB but I think it's a matter of preference.
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Closed 10 years ago.
I am new to the world of MS Access. I have already worked on it for a few days now. What I have done mostly is to look for solutions on web, do some relevant research and get going.
I was wondering if anyone could share:
What is the best way of mastering MS Access?
Any suggestions?
Although it's not the method du jour in a web-based world, my recommendation is NOT to look on the web to try to learn a piece of software because you'll be getting a scattergun effect. You'll be getting a bit here, a bit there, some good techniques, some really poor techniques (and at your skill level no way to know the difference) but more importantly... you won't be getting the required CONTEXT to help you understand the various parts of the product and how they connect into a whole.
I would therefore get a decent introductory level textbook which will normally lead you through understanding basic concepts, building on each one so that you grow into the product as you go. I don't do much with Access any more so I can't recommend a specific book but have found that O'Reilly ( http://search.oreilly.com/?q=Access&x=0&y=0 ) has a range of good books in both paper and digital formats.
If you do want to learn from the web, I'd recommend a structured training program such as the ones offered by Lynda.com or Total Training. I've subscribed to both at various times and although I'm currently a Lynda member, TT's courses are usually quite good as well. There are probably some others but I can't give any first hand recommendations on those.
Good luck with your studies.
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Closed 10 years ago.
I am seeking some more knowledge about MySQL queries. I've been working on building myself as a programmer and now I need to know more about MySQL advanced techniques.
I need to learn about MySQL JOIN queries, CASE, MAX..., everything that I don't already know.
I would really appreciate some links to useful articles with in-depth explanations of advanced MySQL. If you know any good video tutorial about learning MySQL, suggest it, I'm gonna purchase it.
Sorry if this question seems useless to any of you, but it's important to me since I can't keep asking SQL related questions here, I have to learn to do stuff myself.
Thanks.
Having picked up on a couple keywords (video tutorial, purchase), combined with your interest in building your skill set, I'd recommend looking into a subscription on http://www.lynda.com/
Depending on the programming language you're using in conjunction with MySQL, I'd also recommend looking into PDO (assuming you aren't already familiar with it).
Some helpful PDO articles, to supplement your existing knowledge of MySQL:
http://net.tutsplus.com/tutorials/php/php-database-access-are-you-doing-it-correctly/
http://www.phpro.org/tutorials/Introduction-to-PHP-PDO.html
http://returnsuccess.com/post/15-PDO-class-Object-Oriented-PHP
I'd be more helpful, but I can only provide as much information as the question itself.
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Closed 10 years ago.
Which book is best to learn SSIS. Actually in my project we need to take onput from CVS file and after processing the data in SQL server 2008 we have export it back to excel file. ASP.NET is used as UI for this.
Thanks,
Nabin
I completely agree with Cade in terms of simply working with it. I found that trying to follow specific "tutorials" to try and learn the package didn't really help but having a number of useful resources definitely came in handy.
At work, we had this book kicking around but really it just went over the flow objects available without going into any real-world examples. Jamie Thomson's blogs (here and here) are both excellent online resources though and have been really helpful for me personally.
Try this book:
http://www.amazon.com/Professional-Microsoft-Integration-Services-Programmer/dp/0470247959
The best way to learn SSIS is just to do it. Probably best to start and then refer to the book. Because the tool is so GUI intensive, I tended to get more after reading the book later once I was already familiar with the environment somewhat.
Reading the material some times couldn't solve your real time migration by missing some perticular functionality related to your project. I worked on your scenario case of migrating database to SQL using intermediate CSV or text files.
http://msdn.microsoft.com/en-us/library/dd537533(SQL.100).aspx
we migrated nearly 1TB in 30 min using SSIS 2008.
this could help to get the information on specific properties of souce file according to our requirements.
thanks
prav