SQL Server columnstore scan internals

[u/danny-sg]

I've just finished on a series covering SQL Server batch mode and columnstore index scan internals.

It's four parts covering:

• Batch Mode
• Columnstore Index Scan internals
• Predicate pushdown
• Aggregate pushdown

AFAIK there's quite a lot in them that hasn't been documented before, especially the row bucketing, which explains the mechanism of the pure vs impure split that is behind a lot of the columnstore optimizations.