DIAGONAL DATASETS

Data architecture · 2026 · Confidential

DIAGONALDATASETS

The third orientation no one talks about. Data that lives at a perfect 45° angle to both your rows and your columns.

Context / the only two options

Everyone in data talks about exactly two orientations

Nobody voted on this. There was no RFC. The right angle got in early and it has been coasting ever since.

Vertical · 0°

  • Tall tables
  • Many rows
  • Few columns
  • Great for time-series
  • Easy to partition by key

Horizontal · 90°

  • Wide tables
  • Few rows
  • Many features
  • Great for ML features
  • Easy to partition by time

Diagonal · 45°

  • Neither tall nor wide
  • Exactly n cells
  • Great for both, allegedly
  • Partitions by key and time
  • Invariant under transpose

The gap / missing middle

We have been stuck in a false dichotomy for decades

01

Only 0° or 90°

Every paper, every blog, every conference talk. Never 45°. We have checked. We have a spreadsheet, and the spreadsheet is rectangular, which is part of the problem.

02

Wasted space

The diagonal of your warehouse is empty air right now. You are paying for it. You are scanning past it. You have never once looked directly at it.

03

No name for it

If it does not have a name, it does not exist. That is the actual mechanism by which whole categories of engineering stay invisible. We fixed the name first.

The solution / 45° or bust

True 2D partitioning, natural sparsity, and visual elegance

True 2D partitioning

Shard by key and time in a single elegant cut. The diagonal is the only line that moves through both axes at once, which is a fact about geometry that the industry has declined to act on.

Natural sparsity

Most of the matrix is empty by design. Not compressed — empty. Cache efficiency goes brrr. See why this is not a bug report.

Visual elegance

Your data warehouse finally looks like modern art. This is listed third but it is, in the honest accounting, why the project exists.

Mechanics / implementation notes

The math is surprisingly simple

"k">def diagonalize(matrix, bandwidth=1, angle=45):
    """Retain the band. Discard the rest."""
    "k">for r, row "k">in enumerate(matrix):
        "k">for c, value "k">in enumerate(row):
            "k">if abs(c - r) <= bandwidth:
                yield (r, c, value)
            "k">else:
                discard()   "k">class="c"># the rest is just noise

Bandwidth

Control the width of the band. Wider = more data, less pure. Deprecated in draft 4 for reasons we have documented.

Rotation

You can rotate the diagonal. 30° and 60° are still under peer review.

Compression

Diagonal data compresses better because consecutive values are related. This is the one claim on this website that is straightforwardly true.

Applications / real world (ish)

Where diagonal shines

Time-series + features

Features that evolve over time but only near the present. A perfect diagonal band, and you built it by accident to satisfy a retention policy.

Graph adjacency

Local neighborhoods in ordered graphs. The diagonal is the only part that matters and the ordering was chosen to make that true.

Recommendation engines

Users who like item i also like item j when |i-j| is small. Coincidence? No.

Financial risk

Correlations decay with distance in instrument space. Diagonal risk matrices FTW. Every risk desk knows this and stores the full matrix anyway.

Image patches

Nearby pixels. Diagonal in flattened space. You are already doing it. You have been doing it the whole time.

Conference talks

Finally something new to put on the slide after “vertical vs horizontal scaling.” Results have been mixed.

Next steps / the revolution starts now

Stop thinking in rows and columns. Start thinking in diagonals.

The data was always there. We just needed the right angle.

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