Can a table be created as a ColumnStore index?
If you create a table as a columnstore index, you can easily convert the table back to a rowstore table by dropping the columnstore index. Here is a summary of the options and recommendations.
How to create a nonclustered ColumnStore index for the column roomno?
The code will create a nonclustered columnstore index for the column RoomNo for the Kids1 table. If you notice RoomNo is the column selected for the index, this is different than the clustered columnstore index. CREATE NONCLUSTERED COLUMNSTORE INDEX [NCCS-Kids1] ON [dbo].
How to convert rowstore to clustered column store?
If the table is a heap or clustered index the table is converted from rowstore to a columnstore. If the table is already a columnstore, this statement rebuilds the clustered columnstore index. To convert to an ordered clustered column store index the existing index must be a clustered columnstore index.
What’s the difference between NCCI and ColumnStore index?
NCCI is an additional index that requires 10% more storage on average. Same recommendations as nonclustered columnstore index on a disk-based table, except the base table is an in-memory table. Columnstore index is an additional index.
Can you run analytics on a nonclustered ColumnStore index?
Beginning with SQL Server 2016 (13.x), you can have a nonclustered columnstore index on a rowstore disk-based table or an in-memory OLTP table. This makes it possible to run the analytics in real-time on a transactional table. While transactions are occurring on the underlying table, you can run analytics on the columnstore index.
Is there a nonclustered ColumnStore index in SQL Server?
Beginning with SQL Server 2016 (13.x), you can have a nonclustered columnstore index on a rowstore disk-based table or an in-memory OLTP table. This makes it possible to run the analytics in real-time on a transactional table.
How does reorganizing columnstore indexes improve query performance?
Therefore, if you delete data from compressed rowgroups, these rowgroups will still be scanned even though they return fewer rows. If the number of deleted rows for several rowgroups is large enough for these to be merged into fewer rowgroups, then reorganizing the columnstore increases the quality of the index and query performance improves.