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µÚÒ»ÖÖ£ºshrink
ÊÊÓÃÓÚ10gÒÔºóµÄ°æ±¾£¬Ç°ÌáÊÇÕâ¸ö±í£¬Ë÷Òý£¬ÎﻯÊÓͼ»òÎﻯÊÓͼlogËùÔÚ±í¿Õ¼äsegmentµÄ¹ÜÀíÊÇautoµÄ£¬²¢ÇÒ±íÒÑenable row movement£¬È磺
SQL> select owner,segment_name,bytes,blocks,extents from dba_segments
where segment_name = 'EMP';
SQL> alter table emp enable row movement;
SQL> alter table emp shrink space;
SQL> select owner,segment_name,bytes,blocks,extents from dba_segments
where segment_name = 'EMP';
µÚ¶þÖÖ£ºonline redefinition
online redefinitionÔÚoracle 9iÒýÓã¬10g¶ÔDBMS_REDEFINITION°ü×öÁËһЩµ÷Õû£¬Ê¹ÓõIJÙ×÷ÆðÀ´Àí¼òµ¥£¬ÈçÐÂÔö¼ÓµÄCOPY_TABLE_DEPENDENTS£¬UNREGISTER_DEPENDENT_OBJECT£¬·½·¨ÈçÏ£º
1.µ÷ÓÃdbms_redefinition.can_redef_table procedureÈ·ÈÏÊÇ·ñ¿ÉÒÔonline redefinition
SQL> EXECUTE dbms_redefinition.can_redef_table ('FINANCE', 'ACCTS_PAYABLE');
2.ÔÚredefinition schemaÏ´´½¨interim table
3.Èç¹ûredefinitionÒ»¸ö´ó±í£¬¿ÉÒÔÓÃÏÂÃæµÄStatementÀ´¸ÄÉÆÐÔÄÜ:
SQL> alter session force parallel dml parallel degree-of-parallelism;
SQL> alter session force parallel query parallel degree-of-parallelism;
4.µ÷ÓÃdbms_redefinition.start_redef_table procedure¿ªÈçredefinition
SQL> dbms_redefinition.start_redef_table('FINANCE', 'ACCTS_PAYABLE','ACCTS_PAYABLE_STAGE');
5.´´½¨dependent objects on interim table
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µ÷ÓÃdbms_redefinition.copy_table_dependents×Ô¶¯´´½¨dependent objects;
ʹÓÃcreate statementÊÖ¶¯´´½¨dependent objects£¬ÊÖ¶¯´´½¨µÄdependentsÐèÒªµ÷ÓÃregister_dependent_object×¢²á
6.¸üÐÂÔÚredefinition¹ý³ÌÖеĸüе½interim±í
7.µ÷ÓÃdbms_redefinition.finish_redef_tableÍê³Éredefinition
8.ɾ³ýÊջؿռäÈçinterim tableʹÓõıí
×¢£ºÊ¹ÓÃonline redefinitionÐèÒª¶îÍâµÄ¿Õ¼ä
µÚÈýÖÖ£ºalter table … move
ÔÚmoveʱ¿ÉÒÔʹÓõ±Ç°±í¿Õ¼äÒ²¿ÉÒÔÖ¸¶¨ÆäËû±í¿Õ¼ä£¬È磺
SQL> alter table emp move;  
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