columnstore indexes: what was the magic row count for optimum columnstore compression

Question

Remember of hearing it somewhere ... it was something like 900K ... something. Does anybody know what that row count is?

Thanks
Travis

Answer 1

Are you thinking of the rowgroup size? A full rowgroup is 1 048 576 rows. Typically in a columnstore table, you many such rowgroups. Simply because you typically put columnstore on really big tables.

If you have done it already, check out Nico Neugebauer's blog, http://www.nikoport.com/columnstore/. He has a lot of information about colunmstore.

Answer 2

The other magic number is 102,400 (100K) for bulk loading columnstores:

If the batch size is >= 102400, the rows are directly into the compressed rowgroups. It is recommended that you choose a batch size >=102400 for efficient bulk import because you can avoid moving data rows to a delta rowgroups before the rows are eventually moved to compressed rowgroups by a background thread, Tuple mover (TM).

Columnstore indexes - Data loading guidance