1) retailmemberid is INT data type
2) Execution plan shows a complex layout:
delete<-assert<-nested-loop-left-semi-join(0)<-table spool<-assert<-nested-loop-left-semi-join(1)<-nested-loop-left-semi-join(2)<-nested-loop-left-semi-join(3)<-nested-loop-left-semi-join(4)<-nested-loop-left-semi-join(5)<-nested-loop-left-semi-join(6)<-nested-loop-left-semi-join(7)<-table-delete<-index-seek
(0) table-scan
(1) table-scan
(2) index-seek
(3) table-scan
(4)-(7) index-seek
Hope all the above details helps explain things?
Dan