Clustered Columnstore Index Fragmentation - Index Properties and dm_db_column_store_row_group_physical_stats differences

Question

We are using Clustered Column store Indexes in multiple tables. To determine Fragmentation,

1. When I use sys.dm_db_column_store_row_group_physical_stats I see 0% fragmentation,
2. When I query sys.dm_db_index_physical_stats I see 90.10% fragmentation also Index properties show Page fullness as 62.5% and Total fragmentation as 90.10%.

Which fragmentation should be taken as actual fragmentation for my table. And can I remove the fragmentation by rebuild index or rebuild of partitions for column store will work.

Pls suggest.

Answer 1

sys.dm_db_column_store_row_group_physical_stats will show you the columnstore index fragmentation. I'm not sure what would index fragmentation mean in this context since the data's layout on disk is perfectly described byt the above dmv.