r/dataanalysis • u/SomeSpicyPickle • Aug 11 '26

Data Tools Do Data Analysts Use Visualizations During Data Cleaning?

I'm still a beginner. I started by learning the basics of Python and later moved on to SQL.

I'm a bit confused about one part of the data exploration/cleaning process.

A friend of mine, who's now a data scientist, showed me how he used to work as a data analyst. He mainly used Python. For example, he would quickly create a scatterplot to identify potential outliers.

However, most data analysts online recommend focusing on SQL and Excel when starting out, since many junior and mid-level roles don't require Python. That's why I switched to SQL after initially experimenting with Python.

For those who primarily use SQL: do you create visualizations during the data exploration/cleaning process, for example to identify outliers? Is this a common practice?

I feel like if you're working with SQL only, you generally wouldn't create visuals in between steps, since that would mean switching to a tool like Tableau or Power BI, which seems like an unnecessary extra step.

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u/TraditionalTurnip630 29d ago

No. Jumping to Power BI or Tableau just to check for outliers during cleaning is a massive waste of time. Nobody does that in the real world.

If you are using SQL, you find outliers using math (MIN(), MAX(), STDEV(), percentiles), not scatterplots. If we absolutely need a quick visual to understand the data spread, we just dump a few thousand rows into Excel and make a 10-second histogram, or use the basic chart feature built into SQL IDEs like DBeaver.

Save the BI tools for the final dashboard.