On: Vectorized and performance-portable Quicksort

[Denvercoder9]

The data in indexes is stored columnar by most RDBMSes, as far as I know.

[wenc → Denvercoder9]

Typically a rowstore index is a B-tree data structure (on a column) that points to data pages in a rowstore dataset.

It's not technically columnar as such.

You can sort with a rowstore index today, but I imagine you have to materialize the index in some way to take advantage of vectorization.

[janwas → Denvercoder9]

I don't know about "most", but here is a list: https://en.wikipedia.org/wiki/List_of_column-oriented_DBMSes

[ComputerGuru → janwas]

No, this is a list of columnar database systems - gp was saying the index, which is often (but not always) stored separately from the main db records.

[janwas → ComputerGuru]

Ah, indeed, my mistake. FWIW I've observed increasing numbers of papers over the past couple of years mentioning entirely columnar databases.

[kjeetgill → Denvercoder9]

I mean, I guess you could call a B-Tree over a subset of columns "columnar"... And bit-map indexes are by columns too — but that's really bending the definition of what most people mean by columnar storage in databases.

[ddorian43 → Denvercoder9]

It actually is not.