Can a table have Both a Clustered Columnstore Index and Nonclustered Columnstore Index?

Question

Can I a table have both Clustered Columnstore Index and Nonclustered Columnstore Index?

I am seeing example strategies to use Clustered Columnstore Indexes with only Nonclustered Binary row indexes.

When I try creating both a Clustered Columnstore and Nonclustered Columnstore I receive error:

Msg 35339, Level 16, State 1, Line 7
Multiple columnstore indexes are not supported.

Answer 1

No, you can't:

CREATE TABLE dbo.cs_test (id INT NOT NULL)

CREATE CLUSTERED COLUMNSTORE INDEX cs_whatever ON dbo.cs_test

CREATE NONCLUSTERED COLUMNSTORE INDEX nc_whatever ON dbo.cs_test(id);

Returns the error message:

Msg 35339, Level 16, State 1, Line 7 Multiple columnstore indexes are not supported.

The same result for multiple nonclustered columnstore indexes, as well.

Answer 2

There would be little meaning to allow for this. The columns aren't ordered in the index anyhow. Just include all columns that you want in the one and only col-store index that you can have (or if it is clustered, then all columns are already included).

(One could argue that several col-store indexes could be beneficial if we had better control over the build phase in order to control the ability to do row-group elimination. But that would in the end make it difficult for the optimizer in order to decide which col-store index to use unless there would be some statistics over the max-min values in each row-group. Unless you have looked into the internals of col-store index this might not mean much to you... :-) )