Re: query not using index

[Jonathan Cochran]

First off (not a big deal) you only would ever need 2 of the 3 indicies that you created.
"billsec", "calldate" and "billsec,calldate". Anything that uses "billsec" could instead use "billsec,calldate". So you really would only ever need "calldate" and "billsec,calldate" in this example.

Again I do not think this is a huge deal, just something you may want to keep in mind.


2nd, have you tried a smaller date range? Possably 1 day range and see if that uses the index?
MySQL will sometime do a full table scan when it thinks it is faster than using the index. So for example if you where clause is selecting more than 30% of the rows it may just do a full table scan instead of reading the index and then using those pointers to read the table... If you have any questions about this let me know. I will try to answer the best I can. I am still somewhat new to this also.


Jonathan