In MySQL, we have an index optimization in the interval range.

When I tuned MySQL last time, I noticed that some of the statements didn't use the index, which caught my attention and found that in the case of big data, the change of the index policy due to the different data!

Viewing results with the explain command the type becomes index when the data is too large.

The index should minimize the interval range and reduce the results.

PS: In yesterday's SQL ' study, also found if is select * from XXX where lat>xx and lat <xx and lng>xxx and LNG <xxx corrected to select * FROM XXX where lat between xx and xx and LNG between XX and xx better. And the index of LAT and LNG set separately

In MySQL, we have an index optimization in the interval range.