Hello: I am trying to tune the following SQL (in 10.2.0.3) SELECT a.CALL_STRT_TS, count(b.Call_STRT_TS) from IVR.IVC_IVR_CMS_CALL a, IVR.IVC_IVR_CMS_CALL where a.CALL_STRT_TS >= b.CALL_STRT_TS and a.CALL_STRT_TS <= b.CALL_END_TS group by a.CALL_STRT_TS; The goal of this is to count the number of calls that overlap timewise with a current call. So my developer is joinig the table to itself counting all the calls that were in progress when a current call started. The table has about 3.9 mil rows. I think the issue here is that without an equ-join oracle will have to compare each row from the table to every other row. I do see a sort-merge in the explain plan. If I am right, what do I do to speed up this SQL? thank you Gene Gurevich -- //www.freelists.org/webpage/oracle-l