help needed in Aggregates

Hello

right click IC-> maintain aggregates-> drag drop what ever u want to the right side.. save , and make verything green. active..okay..then if i need thsi aggregate to appear in bex what to do

2 nd question,whats the use of performence tab and collapse in IC>>>..

i mean in performence tab u have create index (batch) ..what is the use of it..

please anwser to those question ..

kasinath