Hi, experts: We have a RAC system, in AWR report "gc buffer busy" is top 1 wait (31 Percent Total DB Time), and "gc cr multi block request" is the 2nd (21 Percent Total DB Time) But in AWR report - "Segment Statistics" section ,we can only find there are lots of "Current Blocks Received", not so much "CR Blocks Received". So my question is: Is it possible If a session waiting on "gc cr multi block request" and then it received a "Current Block"? -- Kamus <kamusis@xxxxxxxxx> Visit my blog for more : http://www.dbform.com Join ACOUG: http://www.acoug.org -- //www.freelists.org/webpage/oracle-l