01 September 2010

What's in a name?

The software team I've been working with had a “string or binary data would be truncated” error where we were trying to copy a 100 character “buyer name” column from one table into a 50 character column in another table. We also had a "seller name" column with the potential for the same error and fixed that one up, too.

I took a quick peek at the data to see how the name lengths were distributed in each table. Both names had an average length in the mid- to upper-teens. Virtually none of the names were longer than 50 characters (probably why the bug went unnoticed for years).

Here are a couple visuals of the distribution:

Since this was a reasonably large sample (more than 100,000 names in each column), it probably makes a good guideline for full name column sizing.

As is usual with software defects, the standard “we inherited it” rule applies in this case. Which brings up the quick unrelated observation that I rarely meet developers who claim to write bugs, just folks who inherit them. I'll have to write more on that, later.

At any rate, it seems that bug writers like myself are so prolific that it doesn't take very many of us to keep all the real developers busy.

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