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Clustered Column Store Indexes - STATISTICS?


#1

Heavily using the CCI's for ss2014 DWH use case. CCIs are yielding amazing performance however still endeavouring to tune up workloads and trying to understand the no index, no stats concept with CCIs.

Information on whether you can UPDATE STATs for CCIs is mixed. Does any know if a method exists to UPDATE STATs for CCIs? Or does the Auto update Stats cover this? Believe dbcc show_statistics does not show information validating whether STAT has been updated or not.

Thanks in advance


#2

I recommend Niko's blog series on Columnstore:

He pretty much explains why not here:

The only place where traditional statistics make sense is in the delta store of a CCI, and since those are limited in their row count they typically don't matter...you wouldn't keep so few rows in a CCI anyway.

There are enhancements to columnstore coming to SQL Server 2016 that make regular indexing and statistics more meaningful:

https://msdn.microsoft.com/en-us/library/dn934994.aspx


#3

Thanks Robert,

Was looking at Niko's fantastic blog yesterday after creating this post. Let's see if I can get my client to upgrade to ss2016.

Appreciated.

Martin