비동기 인덱스 정리 (Asynchronous index cleanup)

1. 파티션된 테이블에 대해 DETACH를 수행하면 테이블이 분리된 형태로 보인다.

2. 파티션된 테이블에 파티션되지 않은(Global) 인덱스가 포함되어 있는 경우, 비동기 인덱스 정리 프로세스가 백그라운드로 실행된다.

프로세스는 LIST APPLICATIONS에서 확인할 수 있다.

참조) http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=%2Fcom.ibm.db2.udb.admin.doc%2Fdoc%2Fc0021597.htm

In most cases, one cleaner is started for each non-partitioned index associated with the partitioned table. An internal task distribution daemon is responsible for distributing the AIC tasks to the appropriate database partitions and assigning database agents.

Both the distribution daemon and cleaner agents are internal, system applications. They appear in the LIST APPLICATION output with the application name db2taskd and db2aic, respectively. To prevent accidental disruption, system applications cannot be forced. The distribution daemon remains online as long as the database is active. The cleaners remain activate until the cleaning is complete. If the database deactivates while cleaning is in progress, AIC resumes when the database reactivates.

3. 비동기 인덱스 정리작업에 대한 모니터링은 LIST UTILITIES (SHOW DETAIL)로 확인할 수 있다.

예)

$ db2 list utilities show detail
ID                               = 2
Type                             = ASYNCHRONOUS INDEX CLEANUP
Database Name                    = WSDB
Partition Number                 = 0
Description                      = Table: USER1.SALES, Index: USER1.I2
Start Time                       = 12/15/2005 11:15:01.967939
State                            = Executing
Invocation Type                  = Automatic
Throttling:
   Priority                      = 50
Progress Monitoring:
      Total Work                 = 5 pages
      Completed Work             = 0 pages
      Start Time                 = 12/15/2005 11:15:01.979033
ID                               = 1
Type                             = ASYNCHRONOUS INDEX CLEANUP
Database Name                    = WSDB
Partition Number                 = 0
Description                      = Table: USER1.SALES, Index: USER1.I1
Start Time                       = 12/15/2005 11:15:01.978554
State                            = Executing
Invocation Type                  = Automatic
Throttling:
   Priority                      = 50
Progress Monitoring:
      Total Work                 = 5 pages
      Completed Work             = 0 pages
      Start Time                 = 12/15/2005 11:15:01.980524