From: Date: January 3 2008 9:11pm
Subject: Re: what should an assert_efficient_sql check for?
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Baron Schwartz wrote:

>> Curiously, why would a select-all over 1535 records return 1164 rows?
>>
>> Is that just because >300 were already buffered in memory?
> 
> No, it's just that the 'rows' is an estimate based on storage engine
> statistics, and is wrong.

I can use it for order-of-magnitude estimates, right? A table with 15 records 
and an EXPLAIN rows of 4,901 is probably an issue with your SQL and tables, not 
with the storage engine, right?

And/or, did FLUSH TABLES fix your "wrong"?