\u57289i\u4ee5\u524d\uff0c\u5f88\u591a\u529f\u80fd\u90fd\u662f\u4e0d\u533a\u5206\u8868\u548c\u7269\u5316\u89c6\u56fe\u7684\u533a\u522b\u7684\uff0c\u5230\u4e8610g\u4ee5\u540e\u3002\u5f88\u591a\u529f\u80fd\u4f1a\u5c06\u8868\u548c\u7269\u5316\u89c6\u56fe\u533a\u5206\u5bf9\u5f85\u3002
\n\u539f\u672c\u901a\u7528\u7684COMMENT ON TABLE\u8bed\u53e5\uff0c\u5bf9\u7269\u5316\u89c6\u56fe\u4e0d\u518d\u6709\u6548\uff0c\u5fc5\u987b\u8981\u4f7f\u7528COMMENT ON MATERIALIZED VIEW\u8bed\u53e5\u4ee3\u66ff\u3002<\/p>\n
SQL> SELECT * FROM V$VERSION;\r\nBANNER\r\n----------------------------------------------------------------\r\nOracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi\r\nPL\/SQL Release 10.2.0.4.0 - Production\r\nCORE 10.2.0.4.0 Production\r\nTNS for Linux: Version 10.2.0.4.0 - Production\r\nNLSRTL Version 10.2.0.4.0 - Production\r\nSQL> CREATE TABLE T_BASE (ID NUMBER, TYPE VARCHAR2(30), NUM NUMBER);\r\nTable created.\r\nSQL> CREATE MATERIALIZED VIEW LOG ON T_BASE\r\n2 WITH ROWID, SEQUENCE (TYPE, NUM)\r\n3 INCLUDING NEW VALUES;\r\nMaterialized view log created.\r\nSQL> CREATE MATERIALIZED VIEW MV_BASE\r\n2 REFRESH FAST ENABLE QUERY REWRITE AS\r\n3 SELECT TYPE, SUM(NUM) SUM_NUM, COUNT(NUM) CNT_NUM, COUNT(*) CNT\r\n4 FROM T_BASE\r\n5 GROUP BY TYPE;\r\nMaterialized view created.\r\nSQL> COMMENT ON TABLE MV_BASE IS 'COMMENT ON A MATERIALIZED VIEW ';\r\nCOMMENT ON TABLE MV_BASE IS 'COMMENT ON A MATERIALIZED VIEW '\r\n*\r\nERROR at line 1:\r\nORA-12098: cannot comment on the materialized view\r\n\r\nSQL> COMMENT ON MATERIALIZED VIEW MV_BASE IS 'COMMENT ON A MATERIALIZED VIEW ';\r\nComment created.\r\nSQL> COL COMMENTS FOR A60\r\nSQL> SELECT * FROM USER_MVIEW_COMMENTS;\r\nMVIEW_NAME COMMENTS\r\n------------------------------ ------------------------------------------------------------\r\nMV_BASE COMMENT ON A MATERIALIZED VIEW<\/pre>\n\u5176\u5b9e\u4e0d\u53ea\u662fCOMMENT\u53d1\u751f\u4e86\u53d8\u5316\uff0c\u5173\u4e8e\u7269\u5316\u89c6\u56fe\u7684\u6267\u884c\u8ba1\u5212Oracle\u4e5f\u5bf9\u5176\u8fdb\u884c\u7ec6\u5316\uff0c\u5c06\u7269\u5316\u89c6\u56fe\u7684\u626b\u63cf\u548c\u5168\u8868\u626b\u63cf\u533a\u5206\u5f00\uff1a<\/p>\n
SQL> SET AUTOT ON EXP\r\nSQL> SELECT COUNT(*) FROM MV_BASE;\r\n COUNT(*)\r\n----------\r\n 0\r\nExecution Plan\r\n----------------------------------------------------------\r\nPlan hash value: 3034976462\r\n-------------------------------------------------------------------------\r\n| Id | Operation | Name | Rows | Cost (%CPU)| Time |\r\n-------------------------------------------------------------------------\r\n| 0 | SELECT STATEMENT | | 1 | 2 (0)| 00:00:01 |\r\n| 1 | SORT AGGREGATE | | 1 | | |\r\n| 2 | MAT_VIEW ACCESS FULL| MV_BASE | 1 | 2 (0)| 00:00:01 |\r\n-------------------------------------------------------------------------\r\nNote\r\n-----\r\n - dynamic sampling used for this statement\r\nSQL> SELECT \/*+ REWRITE *\/ TYPE, COUNT(*) FROM T_BASE GROUP BY TYPE;\r\nno rows selected\r\nExecution Plan\r\n----------------------------------------------------------\r\nPlan hash value: 1008429399\r\n----------------------------------------------------------------------------------------\r\n| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |\r\n----------------------------------------------------------------------------------------\r\n| 0 | SELECT STATEMENT | | 1 | 30 | 2 (0)| 00:00:01 |\r\n| 1 | MAT_VIEW REWRITE ACCESS FULL| MV_BASE | 1 | 30 | 2 (0)| 00:00:01 |\r\n----------------------------------------------------------------------------------------\r\nNote\r\n-----\r\n - dynamic sampling used for this statement<\/pre>\n\u57289i\u4ee5\u524d\uff0c\u5f88\u96be\u4ece\u6267\u884c\u8ba1\u5212\u4e2d\u533a\u5206\u626b\u63cf\u7684\u662f\u8868\u8fd8\u662f\u7269\u5316\u89c6\u56fe\uff0c\u4f46\u662f\u73b0\u5728\u4e00\u76ee\u4e86\u7136\u4e86\u3002
\n\u603b\u7684\u6765\u8bf4\uff0c\u8fd9\u79cd\u6539\u8fdb\u8fd8\u662f\u5f88\u6709\u610f\u4e49\u7684\uff0c\u7528\u6237\u53ef\u4ee5\u66f4\u6e05\u695a\u7684\u4e86\u89e3\u5904\u7406\u7684\u5bf9\u8c61\u5230\u5e95\u662f\u8868\u8fd8\u662f\u7269\u5316\u89c6\u56fe\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u57289i\u4ee5\u524d\uff0c\u5f88\u591a\u529f\u80fd\u90fd\u662f\u4e0d\u533a\u5206\u8868\u548c\u7269\u5316\u89c6\u56fe\u7684\u533a\u522b\u7684\uff0c\u5230\u4e8610g\u4ee5\u540e\u3002\u5f88\u591a\u529f\u80fd\u4f1a\u5c06\u8868\u548c\u7269\u5316\u89c6\u56fe\u533a\u5206\u5bf9\u5f85\u3002 \u539f\u672c\u901a\u7528\u7684COMMENT ON TABLE\u8bed\u53e5\uff0c\u5bf9\u7269\u5316\u89c6\u56fe\u4e0d\u518d\u6709\u6548\uff0c\u5fc5\u987b\u8981\u4f7f\u7528COMMENT ON MATERIALIZED VIEW\u8bed\u53e5\u4ee3\u66ff\u3002 SQL> SELECT * FROM V$VERSION; BANNER —————————————————————- Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 – 64bi PL\/SQL Release 10.2.0.4.0 – Production CORE 10.2.0.4.0 Production TNS for Linux: Version 10.2.0.4.0 – Production NLSRTL Version … Continue reading