Which three are true about the Automatic Workload Repository (AWR)?
A)AWR data is stored in the SYSAUX tablespace.
B)Automatic AWR snapshots are created by the Manageability Monitor (MMON) background process.
C)It includes statistics that contain the number of distinct values per table column.
D)By default, AWR data is retained for eight days.
E)it is maintained by executing the pl/sql procedures in the dbms_stats package.
F)It includes statistics that contain the number of rows per table.
Answer: ABD
赵：C、E、F 说的都是优化器的事，和 AWR 没关系。