Oracle 10g分區(qū)表維護中的兩個注意事項
1.全局索引
SQL> alter table analyse_content truncate subpartition DATA0712_DEYANG;
Table truncated
truncate分區(qū)后,修改或者插入數(shù)據(jù)報錯:
ORA-01502: index 'phs.pk' or partition of such index is in unusable state
這個時候只能rebuild index
SQL> alter index phs.pk rebuild;
Index altered
執(zhí)行以后恢復(fù)正常,或者使用如下語句:
SQL> alter table analyse_content truncate subpartition DATA0712_ZIGONG UPDATE
GLOBAL INDEXES;
Table truncated
這樣它會自動恢復(fù)索引。
2.物化視圖
對于已經(jīng)建有fast refresh view的分區(qū)表來說,truncate和drop分區(qū)/表會導(dǎo)致物化視圖出錯。
SQL> alter table analyse_content drop subpartition DATA0712_MIANYANG;
Table altered
SQL> alter table analyse_content truncate subpartition DATA0712_LUZHOU;
Table truncated
再次查詢物化視圖,這個兩個分區(qū)的數(shù)據(jù)仍然存在,說明物化視圖不能對這種DDL語句進行更新。
嘗試在基礎(chǔ)表插入數(shù)據(jù),報錯:
ORA-32313: REFRESH FAST of ' ' unsupported after PMOPs
這時候必須手工刷新MV
SQL> exec dbms_mview.refresh('mv_analyse_content','f');
begin dbms_mview.refresh('mv_analyse_content','f'); end;
ORA-32313: PMOP 之后不支持 'PHS'.'MV_ANALYSE_CONTENT' 的 REFRESH FAST
ORA-06512: 在 'SYS.DBMS_SNAPSHOT', line 2255
ORA-06512: 在 'SYS.DBMS_SNAPSHOT', line 2461
ORA-06512: 在 'SYS.DBMS_SNAPSHOT', line 2430
ORA-06512: 在 line 1
看來快速刷新'f'是不行,還是得完全刷新'c'
SQL> exec dbms_mview.refresh('mv_analyse_content','c');
PL/SQL procedure successfully completed
執(zhí)行完后,MV里面的數(shù)據(jù)恢復(fù)正常,基表不再報錯。
實際10g里面,truncate分區(qū)后,某些物化視圖可以執(zhí)行fast refresh,具體有很多限制,
要查詢doc,反正select * from table這種視圖肯定可以'f',不過卻沒有什么意義。
---2008 04 22 在doc上找到了PCT特性的限制,如下:
At least one of the detail tables referenced by the materialized view must be
partitioned.
Partitioned tables must use either range, list or composite partitioning.
The top level partition key must consist of only a single column.
The materialized view must contain either the partition key column or a partition
marker or ROWID or join dependent expression of the detail table. See Oracle
Database PL/SQL Packages and Types Reference for details regarding the DBMS_
MVIEW.PMARKER function.
If you use a GROUP BY clause, the partition key column or the partition marker or
ROWID or join dependent expression must be present in the GROUP BY clause.
If you use an analytic window function or the MODEL clause, the partition key
column or the partition marker or ROWID or join dependent expression must be
present in their respective PARTITION BY subclauses.
Data modifications can only occur on the partitioned table. If PCT refresh is being
done for a table which has join dependent expression in the materialized view,
then data modifications should not have occurred in any of the join dependent
tables.
The COMPATIBILITY initialization parameter must be a minimum of 9.0.0.0.0.
PCT is not supported for a materialized view that refers to views, remote tables, or
outer joins.
PCT-based refresh is not supported for UNION ALL materialized views.
對于海量數(shù)據(jù)庫,如果不能使用DROP分區(qū),則delete相當(dāng)慢。
如果使用了,又會導(dǎo)致完全刷新MV,同樣慢。
在物化視圖的時候要認真考慮PCT特性。
對于分區(qū)表 已經(jīng)相關(guān)索引,快照的維護,建議還是參考Oracle的DOC,在admin guide和
dataware house guide里有非常完善描述。雖然沒有涉及internal,但完全可以滿足應(yīng)用。
