Hi, Sergei! I'm sorry, my English is not so good! There is no a API to get the exact records in a range, but the API can help to improve performance for the case: select count(*) from t where id > 10 and id < 1000000; I want to know why there is no such a API. Thank you very much! 2011/1/24 Sergei Golubchik <serg@askmonty.org>:
Hi, Lichao!
On Jan 21, Lichao Xie wrote:
No, there is no such a API. The best you can do in your engine is to pay attention to TABLE::read_set and HA_EXTRA_KEYREAD which will allow you to reduce the amount of work you do per key. But still it will be the complete range scan - from the lower to the upper boundary or the range.
Yes. But I want to know that with this use is based on what consideration? the lock or something else?
I am sorry, I cannot understand you. Could you try to rephrase your question please?
Regards, Sergei