Is there a performance decrease if there are too many columns in a table?

mysql database database-design schema
Richard Knop picture Richard Knop · Aug 13, 2010 · Viewed 17.7k times · Source

Is there a performance cost to having large numbers of columns in a table, aside from the increase in the total amount of data? If so, would splitting the table into a few smaller ones help the situation?

Answer

Wade picture Wade · Jul 27, 2011

I don't agree with all these posts saying 30 columns smells like bad code. If you've never worked on a system that had an entity that had 30+ legitimate attributes, then you probably don't have much experience.

The answer provided by HLGEM is actually the best one of the bunch. I particularly like his question of "is there a natural split....frequently used vs. not frequently used" are very good questions to ask yourself, and you may be able to break up the table in a natural way (if things get out of hand).

My comment would be, if your performance is currently acceptable, don't look to reinvent a solution unless you need it.

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