Thanks to everyone that attended Devin’s and my webinar called Choosing The Right Analysis Services: MOLAP vs. Tabular. I’m pleased to announce that the recording is now available to watch for free over at PragmaticWorks.com, so please go check it out. It’s a little less than an hour so you can watch it during your lunch break.
Also, the PowerPoint slide deck Devin and I used during the webinar is also available for viewing now! Please visit this link to download the slide deck.
Now for the questions! Many of you asked some great questions but unfortunately we ran out of time to answer all of the questions during the webinar. So here are a few of the questions we didn’t get to.
Q: How do I link if column have more than one column is key column in tabular?
A: If you need to create a composite key in a Tabular model table, you will need to create a calculated column that concatenate the columns that make up your composite key. You’ll need to do this in both tables you wish to relate. Once you’ve done that, then you can create the relationship between the two tables using your new columns.
Q: Can DAX be used to access cubes?
A: In the SQL 2012 SP1 CU4 release, DAX support for multidimensional cubes was added, so as long as you are running on SQL 2012 SP1 CU4 or later, you should be able to query cubes with DAX expressions. On a side note, MDX can also be used to query a Tabular model.
Q: Since tablular solution is many ways better than Muti Dimensional..then my question is when to go for Multi dimensional solution
A: This is one we covered extensively during the webinar. Here are some of the things to consider:
- How much data are you dealing with? If its too much to fit into memory for your Tabular model, then MOLAP is the way to go.
- Do you have a need for complex relationships? If so, MOLAP may be the answer. Role playing dimensions and many-to-many relationships are possible to create in a Tabular model, but they’re easier to create and manage in a MOLAP cube.
- Do you need to perform many complex calculations involving complex Scope assignments? If so, MOLAP is the answer here.
Q: Can you use a Multidimensional database as the source for a Tabular model and improve performance when creating low level granular reports?? This goes back to the performance differences between Multidimensional vs Tabular when creating granular reports.
A: You can use a Multidimensional database as a data source for a Tabular model, but I would suggest getting the data from the original source for the tabular model. If granular type queries are slow against your cube, those same queries are still going to be slow when you execute them to process your Tabular model.