secondary indexes on InfoCubes

Hello experts!

I had read a lot about indexes here in SDN but I think I don't understand in hole.

Please two questions:

- On the Performance-Tab in InfoCube-Administration what I can check, repair, delete are secondary indexes? I read that primary indexes are build automatically.

- If I just loading normally. One request a day. Are the indexes refreshed every time after load automatically? Primary-Indexes? Secondary Indexes?

I would be very thankfull for a helpful answer.

Kind regards,

Peter