How can you analyze 1mn+ rows data – Excel Interview Question – 02

How-to handle more than million rows in Excel

As part of our Excel Interview Questions series, today let’s look at another interesting challenge. How-to handle more than million rows in Excel?

You may know that Excel has a physical limit of 1 million rows (well, its 1,048,576 rows). But that doesn’t mean you can’t analyze more than a million rows in Excel.

The trick is to use Data Model.

Excel data model can hold any amount of data

Introduced in Excel 2013, Excel Data Model allows you to store and analyze data without having to look at it all the time. Think of Data Model as a black box where you can store data and Excel can quickly provide answers to you.

Because Data Model is held in your computer memory rather than spreadsheet cells, it doesn’t have one million row limitation. You can store any volume of data in the model. The speed and performance of this just depends on your computer processor and memory.

How-to load large data sets in to Model?

Let’s say you have a large data-set that you want to load in to Excel.

If you don’t have something handy, here is a list of 18 million random numbers, split into 6 columns, 3 million rows.

Step 1 – Connect to your data thru Power Query

Go to Data ribbon and click on “Get Data”. Point to the source where your data is (CSV file / SQL Query / SSAS Cube etc.)

Get data > Get & Transform Data options

Step 2 – Load data to Data Model

In Power Query Editor, do any transformations if needed. Once you are ready to load, click on “Close & Load To..” button.

Close & Load to... options in Power Query

Tell Power Query that you want to make a connection, but load data to model.

Load data to Data Model in Excel

Now, your data model is buzzing with more than million cells.

Step 3 – Analyze the data with Pivot Tables

Go and insert a pivot table (Insert > Pivot Table)

Excel automatically picks Workbook Data Model. You can now see all the fields in your data and analyze by calculating totals / averages etc.

You can also build measures (thru Power Pivot, another powerful feature of Excel) too.

How to view & manage the data model

Once you have a data model setup, you can use,

  • Data > Queries & Connections: to view and adjust connection settings
  • Relationships: to set up and manage relationships between multiple tables in your data model
  • Manage Data Model: to manage the data model using Power Pivot
How to manage Data model in Excel - various options

Alternative answer – Can I not use Excel…

Of course, Excel is not built for analyzing such large volumes of data. So, if possible, you should try to analyze such data with tools like Power BI [What is Power BI?] This gives you more flexibility, processing power and options.

Watch the answer & demo of Excel Data Model

I made a video explaining the interview question, answer and a quick demo of Excel data model with 2 million rows. Check it out below or on my YouTube Channel.

Resources to learn about Excel Data Model

  • How to set up data model and connect multiple tables
  • A quick but detailed introduction to Power Query
  • Create measures in Excel Pivot Tables – Quick example
  • Create data model in Excel – Support.Office.com
  • How to use Data Model in Excel – Excelgorilla.com

How do you analyze large volumes of data in Excel?

What about you? Do you use the data model option to analyze large volumes of data? What other methods do you rely on? Please post your tips & ideas in the comments section.

The post How can you analyze 1mn+ rows data – Excel Interview Question – 02 appeared first on Chandoo.org – Learn Excel, Power BI & Charting Online.

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