Excel Is Not a Database (Part 2)


Below is the content of the wiki article entitled “Excel is not a database” as it was at the time I left Tata Steel. There may be some overlap with the contents of the previous blog, but emphasizes the various bullet points where Excel falls in my opinion short of being a satisfactory solution for business reporting. Some items are repeated under different headings, meaning that their bad influence is multi-pronged.

Excel spreadsheets are easy to use and are an ideal tool for ad hoc reporting and investigation of data. However, the fact that it has so many tools, including macros, at its disposal and can hold large amounts of data has misled some people to think of Excel as a database. This is a fatal error, because it leads people to think that it’s OK to employ Excel (and any other type, for that matter) spreadsheets for business reporting.

Below is a shortlist of various reasons why those using Excel as a database are badly mistaken:

Localised Copy

  • Unlike a web application, Excel is a one-user-at-a-time application – it’s not sharable unless you email it (Modern Databases Are Naturally Multi-User)
  • Large Excel spreadsheets use up RAM in a way that interrogating a database doesn’t (Databases Can Work with Database Files Much Larger Than Available RAM)
  • Information silos caused by localised nature and need for in-depth knowledge of the spreadsheet (super-spreadsheets need super-spreadsheet experts)
  • Encourages silo mentality and data hiding

Accessibility

  • Unlike a web application, Excel is a one-user-at-a-time application – it’s not sharable unless you email it (Modern Databases Are Naturally Multi-User)
  • Large Excel spreadsheets use up RAM in a way that interrogating a database doesn’t (Databases Can Work with Database Files Much Larger Than Available RAM)
  • Encourages silo mentality and data hiding

Data Integrity

  • There’s no centrally controlled master copy with the officially sanctioned data, and anyone can adjust their copy to their liking
  • Data errors are not corrected at source
  • Correction of identical information that exists in multiple places
  • Multiplication of spreadsheets for multiple reporting purposes
  • Manual entry without error checking
  • Data trail from raw data to final report becomes confused
  • Arguments over what constitutes the “real” figures
  • Multiple hits against data sources for individual reports that have large amount of overlap

“Sophisticated” Spreadsheets

  • Fancy Excel spreadsheets require you to write macros in VBA – you may as well spend that time learning how to program properly on a database
  • “Sophisticated” spreadsheets become impenetrable to the uninitiated
  • Information silos caused by localised nature and need for in-depth knowledge of the spreadsheet (super-spreadsheets need super-spreadsheet experts)

Static Copies

  • The data layer and the presentation layer are inextricably linked – if you want an additional column for some calculation, you need to physically create that column
  • Excel doesn’t have inherent back-up/restore capabilities
  • Lack of drilldown facilities, so that in meetings the reported figures can’t be interpreted
  • Summarising daily figures into weekly figures into monthly figures etc. without manual intervention
  • Snapshots miss subsequent alterations to the feeder data

Manual Effort

  • Spreadsheets always need someone to look after them
  • Multiple hits against data sources for individual reports that have large amount of overlap
  • Summarising daily figures into weekly figures into monthly figures etc. without manual intervention
  • Updating of super-spreadsheets can take a long time – reports may take days to be available to decision makers or otherwise massive manual effort needs to be made to speed up the reporting phase
  • Different contributors often need to be chased to update the spreadsheet
  • Data specialists should spend their time analysing and understanding data rather than creating and fine-tuning spreadsheets (= opportunity cost)

And there’s a lot more where this came from under “Other”, but I suppose you get the gist …

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