yeah thx, much better now, I was just wondering about my 2nd question, because I was confused by "clean pages" , those that are in fact, the dirty (modified) pages...

yeah, the third and the fourth page in the data file, what exactly is the data file? its not the .mdf file I think...?

it would be too easy to just...

ah ok I understand, so in each database file, there are those type of pages somewhere that keep track of these data pages etc. and everything what is inside each...

ok, so can anybody tell me what a database file is ?

Every database file has its own chain of GAM and SGAM pages. The first GAM page is always...

yeah I mean they're not all file pages, but pages, there are 13 different pages.. so where are the GAM,SGAM and PFS pages stored ?

edit: ok I think I found...

ok I think I kind of figured it out, it's sort of memory-optimized.... they compress the columns into segments and store them on disk as BLOB's, the columnstore index itself...

hm ok, but why is it then said that columnstore indexes are "in-memory" ??that confuses me..

I read part of the whitepaper, it said the data columns are stored as...

I already looked into Microsoft Documentation but that wasnt helpful -.-

the inner structure of the Columnstore Index and how data in memory is represented is not written there... hope someone...