Looks like they just recreated a tuple layout in rust with null bit map and everything, next up would be storing them in pages and memmap the pages.
https://www.postgresql.org/docs/current/storage-page-layout....
https://www.postgresql.org/docs/current/storage-page-layout....
I wasn't sure about writing the article in the first place because of that, but I figured it may be interesting anyways because I was kind of happy with how simple it was to write this optimization when it was all done (when I started out with the task I wasn't sure if it would be hard because of how our code is structured, the libraries we use etc.). I originally posted this in the rust community, and it seems people enjoyed the post.
It comes off as being a novel solution rather than connecting it to a long tradition of DB design. I believe PG for instance has used a null bitmap since the beginning 40 years ago.
Using bitmaps to indicate whether things are in-use or not is very common in systems programming. Like you said PG does it, but most other systems do this too. It's not specific to databases: in an operating system, one of the first thing it needs is an allocator, the allocator most likely will use some bitmap trick somewhere to indicate what's free vs. what's available etc.
>The fix is simple: we stop storing Option<T> and instead we store a bitmap that records which fields are None.
Right here would have been the opportunity to let those not familiar with database internals know. Something like "This technique has been widely used in many RDBMS systems over the years, you can see the PG version of this in their documentation for page layout".
Instead you go into detail on what a null bitmap is and how to implement it, calling it a "trick". Which is strange if you think your target audience is assumed to already know this common technique.
I mean not one mention of the origin of the trick or even calling it a common solution to this problem...
And who or what would you say is the origin? The "trick" is so old I'm afraid it is lost to time to say who invented the bitmap. It was used in MULTICS or THE long before PostgreSQL was invented.
Your version comes off as self promotion, going into detail how to implement a the technique with out once calling it a common technique or even mentioning its widely used in the industry to solve the problem you are solving.
It would be like saying finding rows in storage is slow so we implemented a b-tree in a separate structure for certain columns and go into detail how to create a b-tree, calling it a "trick" while never once acknowledging the is the most common form of indexing in RDBMS's, would you understand how this would seem strange?