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by slackerIII 1481 days ago
What would it take for something like this to make it into Postgres?
2 comments

unlikely - postgres stores data row-wise and this assumes sequentially stored columns. They even mention that issue in the blog post.

It would be more likely to show up in something like Apache Arrow which is designed columnar to leverage these sort of tricks

There are various Postgres extensions (such as Citus) that are columnar, so with them it should be possible.
How about AWS Redshift which is columnar (though that is also based on Postgres)...
The data in indexes is stored columnar by most RDBMSes, as far as I know.
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.

I don't know about "most", but here is a list: https://en.wikipedia.org/wiki/List_of_column-oriented_DBMSes
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.
Ah, indeed, my mistake. FWIW I've observed increasing numbers of papers over the past couple of years mentioning entirely columnar databases.
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.
It actually is not.