Listen, yesterday I was poking around with DataTable Pro (app) and ended up chasing a performance issue that looked like “the app is slow” but turned out to be very specific — and fixable.

So here’s the situation.

DataTable Pro is basically a data management and spreadsheet-style analysis tool. Think large tables, sorting, filtering, exporting — that kind of workflow. Not from the Mac App Store, more of a standalone utility. If you’re ever comparing tools, the general App Store entry point is here:
https://apps.apple.com/

Anyway, the problem wasn’t that it wouldn’t open. It launched fine. The issue was lag. Big, ugly lag when working with larger datasets — like 50k+ rows. Scrolling stuttered, sorting took several seconds, and sometimes the UI froze briefly when applying filters.

At first glance, it felt like the app just wasn’t optimized well.

What I did first (and what didn’t help)

My first assumption was hardware. Maybe my machine was under load. So I opened Activity Monitor.

CPU usage was modest. Memory usage was high-ish but not catastrophic. No obvious red flags.

Then I thought maybe the dataset itself was malformed — weird encoding, huge text blobs, something like that. So I trimmed the file down to 10k rows. Everything became smooth.

That’s when I thought, okay, maybe it just doesn’t scale well.

But I wasn’t convinced yet. Because even with 50k rows, this shouldn’t feel like molasses on modern hardware.

So I dug a little deeper.

What I realized

Data-heavy apps often rely on either in-memory rendering or some form of virtualized table view. If they try to render all rows at once instead of virtualizing (rendering only visible rows), performance tanks fast.

In this case, I suspected that the app was recalculating derived columns and re-sorting the entire dataset on every minor interaction.

I confirmed part of that by watching CPU spikes during sorting. Even simple sorts triggered heavy single-threaded usage.

Then I noticed something else: “Live recalculation” was enabled by default in preferences. That meant every change — even typing into a filter box — triggered a full recompute of all calculated columns.

That was the real culprit.

What actually helped

I went into Preferences and disabled live recalculation. Switched it to manual apply.

After that, filtering no longer triggered immediate recomputation. The UI stayed responsive, and calculations ran only when I explicitly applied them.

The difference was night and day.

Scrolling also improved once I disabled “Auto-adjust column widths.” Apparently, every time you scrolled horizontally, it was recalculating layout for dynamic column sizing.

So the lag wasn’t random. It was death by a thousand automatic features.

While I was digging around, I found this page useful — the resource I used:
https://dejavu-ks.com/developer/43874-datatable-pro.html

It helped confirm that performance complaints often tied back to default settings rather than core engine limitations.

Why this happens in data tools

Large datasets amplify every inefficiency. If an app:

  • Re-renders all rows instead of virtualizing
  • Recomputes formulas eagerly
  • Recalculates layout dynamically
  • Performs synchronous sorting on the main thread

You’ll feel it instantly.

From a macOS standpoint, there’s nothing wrong. It’s not a security issue or compatibility bug. It’s architectural trade-offs.

Apple’s guidance on performance optimization for macOS apps touches on keeping heavy work off the main thread:
https://developer.apple.com/documentation/xcode/improving_app_responsiveness

And generally, keeping UI work lightweight is critical. If heavy computation blocks the main run loop, you get visible freezes.

In DataTable Pro’s case, it seems optimized for convenience by default rather than performance at scale.

One more thing I tested

I exported the dataset to CSV and re-imported it after cleaning unnecessary columns. That alone reduced memory usage significantly.

I also split one massive table into two smaller logical groups. Instead of 60k rows in one view, I had 30k + 30k. That made sorting noticeably faster.

So part of the solution was behavioral: don’t treat it like a database engine if it isn’t one.

After the tweaks

Once I disabled live recalculation and auto column resizing, performance became totally acceptable. Not lightning fast, but smooth enough for real work.

No more scroll stutter. No multi-second freezes when applying filters. CPU spikes became shorter and less frequent.

Which made it clear: the app wasn’t fundamentally broken. It was just doing too much automatically.

What I’ll do differently next time

When a data tool feels slow, I won’t immediately blame poor coding. I’ll check for:

  • Auto recalculation
  • Real-time filtering
  • Dynamic layout adjustments
  • Background indexing

Because convenience features often cost performance.

Quick checklist for future me

  • Disable live recalculation on large datasets.
  • Turn off auto-adjust column widths.
  • Reduce unnecessary calculated columns.
  • Split massive datasets if possible.
  • Watch Activity Monitor for main-thread CPU spikes.

After going through all this, I actually appreciate DataTable Pro more. It’s flexible — maybe too flexible by default.

It’s funny how often “this app is slow” really means “this app is doing exactly what you asked, just very enthusiastically.”

Anyway, if you ever load a big dataset into DataTable Pro and it feels like it’s dragging its feet, check those automatic features first. Chances are, it’s not your machine. It’s just the app trying a little too hard to be helpful.

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Pub: 27 Feb 2026 15:53 UTC

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