Re: [NF] How many indexes do you need?

On Oct 10, 2018, at 8:54 PM, Gene Wirchenko genew@telus.net wrote:

...

I think the point of the article was to help remind people to think about indexes before just using them without understanding the effects on performance. Having a rule of thumb like 5 indexes per table would make me stop and consider whether a 6th index was required. If so, then great. But at least I would have thought about the benefits and negatives before doing it. Frankly, reminding people to consider the consequences of their actions is NEVER stupid advice.

Sure.  But putting an arbitrary in is not good advice.  In a given case, it might be that having a fifth index is wrong, or maybe, it is fine until the tenth index.

“Rule of thumb” is not the same as “arbitrary”.

The former is based upon experience and observation. The latter is pulled out of thin air.

-- Ed Leafe