Dr. Codd Was Right: A Hop, A Skip, and A Jump

The Kleptocracy of Muskistan Devours You

The world is not linear.
-- Dr. McElhone/1974

[T]he massive push to relocate federal jobs outside the Beltway comes with the risk of kneecapping agencies through the loss of experienced workers and bogging them down in logistical minutia.
-- Curt Devine/2024 [that's the point: make the Damn Gummint incompetent, then destroy it because it's incompetent]

Scientists aren't vocal enough about science. There are large groups of people who think scientists are all frauds and who don't believe in science, and they're being cultured by some of our far right-wing politicians, religious leaders and community leaders.
-- Drew Weissman/2022

To date, Microsoft is stating that organizations testing In-Memory OLTP have seen transaction speeds improve by up to 30 times compared to past performance, with the best performance gains achieved when the business logic resides in the database and not in the applications.
-- Jonathan Watts/2015 [my emphasis]

I have had to explain and re-explain and re-explain and re-explain, you know, how relational databases work, what is an eigenvector, what is dimensionality reduction.

-- Christopher Wylie/2018

... but Flash-based storage has such a different performance profile from rotating media, that I suspect that it will end up having a large impact on filesystem design. Right now, most filesystems tend to be designed with the latencies of rotating media in mind.

-- Linus Torvalds/2007

I believe quite strongly that, if you think about the issue at the appropriate level of abstraction, you're inexorably led to the position that databases must be relational.

-- Chris Date/2009

This Week's thought

[Scotland's HPV] vaccination program began in 2008, and so far the women who were vaccinated as 12- or 13-year-olds have shown not one single case of cervical cancer. And the rate in women who were vaccinated at later ages was 80% lower than the unvaccinated. Cervical cancer is almost completely preventable through such vaccination programs, and the anti-vaccine activists who have come out against them (such as the dangerous fool nominated to be secretary of HHS) can go to hell.
-- Derek Lowe/2024 [the morons will be running the asylum, if we let them]

See you next week in a brand new show^{©Heckle and Jeckle}

Therefore:

In a time of SSD, multi-core/processor, two terabyte memory and Optane App Direct Mode machines, there is no reason not to build from BCNF data. Time to do what Dr. Codd demonstrated. Technology has finally caught up with the maths.

04 June 2018

A Hop, A Skip, and A Jump - part the fifth

Yet another carrot for the stew, a paper from last year directly discussing RDBMS on PM. Of all the references so far in this series, this one is *a must read*. Really. Not just because it validates every notion flowing from my noggin. No, not at all.

In this tutorial, we provide an outline on how to build a new DBMS given the changes to hardware landscape due to NVM.

Yum. And it's from what was Carnegie Tech (which accepted me, but I ended up going elsewhere), one of the first Computer Science curriculums!

In the case of memory-oriented DBMSs (e.g., VoltDB, MemSQL), they contain components for overcoming the volatility of DRAM. Such components may be unnecessary in a system with byte-addressable NVM with fast random access.

Exactly why the announced kludges for *nix/Windows aren't the end. The OS/400 turns out to be the winner. In some form.

Peloton is an open-source HTAP DBMS that we are building that is designed from the groundup to use NVM. Our intended audience are developers, researchers, and practitioners with knowledge of DBMS internals. They do not need any in-depth background or experience with NVM.

Here we see another step closer to the OS/400 model:

To cope with these shorter NVM latencies, Microsoft and Linux are adding support for direct access storage (DAX) in Windows Server 2016 [48] and Linux 4.7 [1], respectively. With DAX, a DBMS directly allocates and uses NVM without an intervening filesystem. This requires only one copy between the file and the user buffers, thus improving the file I/O performance by an order of magnitude compared to block-oriented filesystems.
[my bold]

Recall an earlier part of this series' mention that transaction semantics will be different with PM? Make it so:

The write-ahead logging (WAL) protocol supports efficient transaction processing when memory is volatile and durable storage cannot support fast random writes [58, 39, 33]. But this assumption causes unnecessary performance degradations in a DBMS with NVM storage [14]. Consider a transaction that inserts a tuple into a table. A DBMS first records the tuple's contents in the log, and it later propagates the change to the database. With NVM, a DBMS can employ a logging protocol that avoids this unnecessary data duplication. The reason why NVM enables a better logging protocol than WAL is two-fold. The write throughput of NVM is more than an order of magnitude higher than that of an SSD or HDD. Further, the gap between sequential and random write throughput of NVM is smaller than that in SSD and HDD. Hence, a DBMS can flush changes directly to the database in NVM during regular transaction processing [15, 14, 12, 64, 40, 62, 80].

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Dr. Codd Was Right

The Kleptocracy of Muskistan Devours You

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04 June 2018

A Hop, A Skip, and A Jump - part the fifth

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