数据库巡检时发现数据库在搜集统计信息时发现有索引unusable，
Tue Sep 09 22:52:07 CST 2014
GATHER_STATS_JOB encountered errors. Check the trace file.
Tue Sep 09 22:52:07 CST 2014
Errors in file /oracle/product/10.2/db_1/admin/dcods/bdump/dcods1_j003_9961660.trc:
ORA-20000: index "OMCW_OWNER"."PK_EQ_EXCP_OVERVIEW" or partition of such index is in unusable state
haods1:/home/oracle$more /oracle/product/10.2/db_1/admin/dcods/bdump/dcods1_j003_9961660.trc
/oracle/product/10.2/db_1/admin/dcods/bdump/dcods1_j003_9961660.trc
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options
ORACLE_HOME = /oracle/product/10.2/db_1
System name: AIX
Node name: haods1
Release: 1
Version: 6
Machine: 00F773F14C00
Instance name: dcods1
Redo thread mounted by this instance: 1
Oracle process number: 97
Unix process pid: 9961660, image: oracle@haods1 (J003)
*** 2014-09-09 22:52:07.689
*** ACTION NAME:(GATHER_STATS_JOB) 2014-09-09 22:52:07.684
*** MODULE NAME:(DBMS_SCHEDULER) 2014-09-09 22:52:07.684
*** SERVICE NAME:(SYS$USERS) 2014-09-09 22:52:07.684
*** SESSION ID:(2374.62337) 2014-09-09 22:52:07.684
ORA-20000: index "OMCW_OWNER"."PK_EQ_EXCP_OVERVIEW" or partition of such index is in unusable state
*** 2014-09-09 22:52:07.689
GATHER_STATS_JOB: GATHER_TABLE_STATS('"OMCW_OWNER"','"EQ_EXCP_OVERVIEW"','""', ...)
ORA-20000: index "OMCW_OWNER"."PK_EQ_EXCP_OVERVIEW" or partition of such index is in unusable state
在dba_indexes里发现此索引确实是”UNUSABLE"
解决办法：alter index OMCW_OWNER.PK_EQ_EXCP_OVERVIEW rebuild online;
使用online选项，允许在重建索引的时候更新基础表。