What’s New In Analysis Services 2016 Multidimensional?

Reposted from Chris Webb's blog with the author's permission.

With the recent release of SQL Server 2016 some of you old faithful SSAS Multidimensional users out there might be wondering if it’s worth upgrading. There is an official page describing what’s new in Analysis Services 2016 here:

https://msdn.microsoft.com/en-us/library/bb522628.aspx

…but it’s mostly concerned with SSAS Tabular and, unfortunately, it’s somewhat misleading. For example, it says:

a number of enhancements have been made to multidimensional models; for example, distinct count ROLAP optimization for data sources like DB2 and Oracle, drill-through multi-selection support with Excel 2016, and Excel query optimizations.

In fact the drillthrough/multi-select improvements (which I blogged about here) already shipped as part of SSAS 2014 and are reliant on improvements in Excel 2016 as much as in SSAS; similarly the Excel 2016 query optimisations are not reliant on any changes in SSAS 2016 and will benefit users of all versions of SSAS.

So what has actually changed with SSAS 2016 Multidimensional? I don’t know all the details on every change, but here’s what I know right now:

• As the above quote shows, there have been improvements in ROLAP distinct count performance for DB2 and Oracle. I’ve also heard there are improvements for the SQL generated in ROLAP mode to take advantage of SQL Server’s columnstore indexes.
• We now have Database Consistency Checker for SSAS, which you can read more about here or in Dustin Ryan’s post here. For Multidimensional it will only tell you whether your partition indexes are corrupt (it does a lot more for Tabular) and if they are you need to delete the database and then either restore it or re-deploy/reprocess.
• Extended Events for SSAS now have UI support in SQL Server Management Studio, although the UI still looks like it needs some work. I still see myself using Profiler for my SSAS performance tuning work for the foreseeable future – or at least until I work out what the extra information that Extended Events give you is useful for. I know other people, like Bill Anton, are more excited about Extended Events and their possibilities though.
• You can now use computer accounts to be members of the Analysis Services Administrators group in SQL Server Management Studio.
• If you are developing applications that need to create, alter, process or otherwise do stuff to an Analysis Services database in .NET code then you need to be aware that Analysis Management Objects (AMO) has been refactored to include a second assembly which “paves the way for future extensions to AMO, with clear division between generic and context-specific APIs”.
• There’s a new default setting for the MemoryHeapType server property that helps to avoid memory fragmentation and is relevant to Tabular and Multidimensional; Marco Russo has the details here.

Not the most exciting or inspiring set of changes, I have to say, even if there’s lots of cool new stuff in SSAS Tabular 2016. There are also usually other fixes and improvements like the MemoryHeapType property that get added but are never documented, and when I find out about them I’ll be sure to blog or tweet. If you find any please let me know!

Chris has been working with Microsoft BI tools since he started using beta 3 of OLAP Services back in the late 90s. Since then he has worked with Analysis Services in a number of roles (including three years spent with Microsoft Consulting Services) and he is now an independent consultant specialising in complex MDX, Analysis Services cube design and Analysis Services query performance problems. His company website can be found at http://www.crossjoin.co.uk and his blog can be found at http://cwebbbi.wordpress.com/ .