'Ballparking' Number of DB Records to Save Cpu Cycles

I noticed Gmail started to 'ballpark' the number of results for searches and wondered if this was simply an aesthetic change or if it actually saved on cpu cycles.

When performing a search in Gmail it says something along the lines of

Viewing 10 results of (hundreds, thousands, etc)

开发者_运维问答

Are there SQL techniques for this? Are there performance benefits?

Anything to point me in a direction to learn more would be helpful.

pretty sure google search is not using mysql. But you can ball park a table's size in mysql by doing

show table status like 'table_name';