SQL Server Clustered Column Index Memeory

Question

I am researching the use of the new Clustered Column Indexes in SQL 2014. When MS says these are "in-memory" what exactly does that mean? These days the "in memory" moniker is thrown around alot. Does it mean that the entire table is constantly in memory? Or does it get swapped out to disk. I do not want to use if the entire table is constantly in memory.

Thanks!

Answer 1

Columnstore indexes are brought into memory (and cached) segment-wise. Segments are usually small. It would be rare to see a 10MB segment. A segment is 1 million rows of a a single column.

So you see not the entire table must be in-memory at the same time.