{"id":362,"date":"2011-11-24T08:18:16","date_gmt":"2011-11-24T00:18:16","guid":{"rendered":"https:\/\/blog.rexdf.org\/?p=362"},"modified":"2011-11-24T08:18:16","modified_gmt":"2011-11-24T00:18:16","slug":"oracle-truncate-table-%e4%b8%8e-delete-tabel%e7%9a%84%e5%8c%ba%e5%88%ab","status":"publish","type":"post","link":"https:\/\/blog.rexdf.org\/ja\/2011\/11\/oracle-truncate-table-%e4%b8%8e-delete-tabel%e7%9a%84%e5%8c%ba%e5%88%ab\/","title":{"rendered":"Oracle truncate table \u4e0e delete tabel\u7684\u533a\u522b"},"content":{"rendered":"
<\/div>\n
\n
\n

\u3000\u4e00\u3001<\/span><\/span><\/span><\/p>\n

1.delete\u4ea7\u751frollback\uff0c\u5982\u679c\u5220\u9664\u5927\u6570\u636e\u91cf\u7684\u8868\u901f\u5ea6\u4f1a\u5f88\u6162\uff0c\u540c\u65f6\u4f1a\u5360\u7528\u5f88\u591a\u7684rollback segments .truncate \u662fDDL\u64cd\u4f5c\uff0c\u4e0d\u4ea7\u751frollback\uff0c\u901f\u5ea6\u5feb\u4e00\u4e9b.
<\/span>\u3000\u3000
<\/span>\u3000\u3000Truncate table does not generate rollback information and redo records so it is much faster than delete.
<\/span>\u3000\u3000
<\/span>\u3000\u3000In default, it deallocates all space except the space allocated by MINEXTENTS unless you specify REUSE STORAGE clause.
<\/span>\u3000\u3000
<\/span>2.\u4e0d\u4ecetablespace\u4e2d\u817e\u51fa\u7a7a\u95f4,\u9700\u8981
<\/span>\u3000\u3000
<\/span>\u3000\u3000ALTER TABLESPACE AAA COALESCE; \u624d\u6709\u7a7a\u95f4
<\/span>\u3000\u3000
<\/span>3.truncate \u8c03\u6574high water mark \u800cdelete\u4e0d.truncate\u4e4b\u540e\uff0cTABLE\u7684HWM\u9000\u56de\u5230 INITIAL\u548cNEXT\u7684\u4f4d\u7f6e\uff08\u9ed8\u8ba4\uff09
<\/span>\u3000\u3000
<\/span>\u3000\u3000delete \u5219\u4e0d\u53ef\u4ee5\u3002
<\/span>\u3000\u3000
<\/span>4.truncate \u53ea\u80fd\u5bf9TABLE
<\/span>\u3000\u3000
<\/span>\u3000\u3000delete \u53ef\u4ee5\u662ftable,view,synonym
<\/span>\u3000\u3000
<\/span>5.TRUNCATE TABLE \u7684\u5bf9\u8c61\u5fc5\u987b\u662f\u672c\u6a21\u5f0f\u4e0b\u7684\uff0c\u6216\u8005\u6709drop any table\u7684\u6743\u9650 \u800c DELETE \u5219\u662f\u5bf9\u8c61\u5fc5\u987b\u662f\u672c\u6a21\u5f0f\u4e0b\u7684\uff0c\u6216\u88ab\u6388\u4e88 DELETE ON SCHEMA.TABLE \u6216DELETE ANY TABLE\u7684\u6743\u9650<\/span><\/span><\/span><\/span><\/p>\n

\n

\u4e8c\u3001 truncate\u662fDDL\u8a9e\u8a00.
<\/span>delete\u662fDML\u8a9e\u8a00

<\/span>DDL\u8a9e\u8a00\u662f\u81ea\u52d5\u63d0\u4ea4\u7684.
<\/span>\u547d\u4ee4\u5b8c\u6210\u5c31\u4e0d\u53ef\u56de\u6efe.

<\/span>truncate\u7684\u901f\u5ea6\u4e5f\u6bd4delete\u8981\u5feb\u5f97\u591a.<\/span><\/span><\/span><\/span><\/p>\n

\n

\u4e09\u3001 truncate \u4f1a\u628a highwatermark \u56de\u5f52\u81f3 0 … \u5f53\u4e0b\u4e00\u6b21\u518d\u63d2\u5165\u65b0\u8d44\u6599\u65f6\u5c31\u4f1a\u5feb\u4e00\u4e9b\u5566\u3002

<\/span>\u6240\u4ee5\u4e00\u822c\u90fd\u662f\u5728 temp table \u4e0a\u4f7f\u7528\u7684\uff0c\u4e0d\u8fc7\u8981\u6ce8\u610f\u5c31\u662f truncate \u4e0d\u80fd\u5728 pl\/sql \u4e0a\u4f7f\u7528\uff0c\u8981\u7528 dynamic SQL \u624d\u53ef\u4ee5\u3002<\/span><\/span><\/span><\/span><\/p>\n

\n

\n

\u56db\u3001<\/span><\/span><\/p>\n

\u5f53\u4f60\u4e0d\u518d\u9700\u8981\u8be5\u8868\u65f6\uff0c \u7528 drop;
<\/span>\u5f53\u4f60\u4ecd\u8981\u4fdd\u7559\u8be5\u8868\uff0c\u4f46\u8981\u5220\u9664\u6240\u6709\u8bb0\u5f55\u65f6\uff0c \u7528 truncate;
<\/span>\u5f53\u4f60\u8981\u5220\u9664\u90e8\u5206\u8bb0\u5f55\u65f6\uff08always with a WHERE clause), \u7528 delete.<\/span><\/span><\/span><\/span><\/p>\n

\n

\n

\u4e94\u3001<\/span><\/span><\/p>\n

1.TRUNCATE TABLE<\/span><\/span><\/p>\n

I<\/span><\/span>ndex\u4e5f\u6703\u522a\u6389\u4e0d\u662f\u6307drop index

<\/span>sys@DEMO> create index tom.idx_object_name on tom.t(object_name);

<\/span>\u5df2\u5efa\u7acb\u7d22\u5f15.

<\/span>sys@DEMO> select block_id,bytes from dba_extents where segment_name=’IDX_OBJECT_NAME’;

<\/span>BLOCK_ID BYTES
<\/span>———- ———-
<\/span>17321 65536
<\/span>17329 65536
<\/span>17337 65536
<\/span>17345 65536
<\/span>17353 65536
<\/span>17361 65536
<\/span>17369 65536
<\/span>17377 65536
<\/span>17385 65536
<\/span>17393 65536
<\/span>17401 65536
<\/span>17409 65536
<\/span>41865 65536
<\/span>41873 65536
<\/span>41897 65536
<\/span>41905 65536
<\/span>18953 1048576
<\/span>19081 1048576
<\/span>19209 1048576
<\/span>19337 1048576

<\/span>\u5df2\u9078\u53d6 20 \u500b\u8cc7\u6599\u5217.

<\/span>sys@DEMO> TRUNCATE TABLE TOM.T;

<\/span>\u8868\u683c\u88ab\u622a\u65b7.

<\/span>sys@DEMO> select block_id,bytes from dba_extents where segment_name=’IDX_OBJECT_NAME’;

<\/span>BLOCK_ID BYTES
<\/span>———- ———-
<\/span>17321 65536<\/span><\/span>
<\/span><\/p>\n

\n

\n

2.DELETE table<\/span><\/span><\/p>\n

sys@DEMO> insert into tom.t select * from all_objects;

<\/span>\u5df2\u5efa\u7acb 27747 \u500b\u8cc7\u6599\u5217.

<\/span>sys@DEMO> insert into tom.t select * from all_objects;

<\/span>\u5df2\u5efa\u7acb 27747 \u500b\u8cc7\u6599\u5217.

<\/span>sys@DEMO> commit;

<\/span>\u78ba\u8a8d\u5b8c\u6210.

<\/span>sys@DEMO> select block_id,bytes from dba_extents where segment_name=’IDX_OBJECT_NAME’;

<\/span>BLOCK_ID BYTES
<\/span>———- ———-
<\/span>17321 65536
<\/span>17201 65536
<\/span>17241 65536
<\/span>17265 65536
<\/span>17297 65536
<\/span>17353 65536
<\/span>17369 65536
<\/span>17377 65536
<\/span>17385 65536
<\/span>17393 65536
<\/span>17401 65536
<\/span>17409 65536
<\/span>41865 65536
<\/span>41873 65536
<\/span>41897 65536
<\/span>41905 65536
<\/span>17673 1048576
<\/span>17801 1048576
<\/span>18185 1048576
<\/span>18441 1048576

<\/span>\u5df2\u9078\u53d6 20 \u500b\u8cc7\u6599\u5217.

<\/span>sys@DEMO> delete from tom.t;

<\/span>\u5df2\u522a\u9664 55494 \u500b\u8cc7\u6599\u5217.

<\/span>sys@DEMO> select block_id,bytes from dba_extents where segment_name=’IDX_OBJECT_NAME’;

<\/span>BLOCK_ID BYTES
<\/span>———- ———-
<\/span>17321 65536
<\/span>17201 65536
<\/span>17241 65536
<\/span>17265 65536
<\/span>17297 65536
<\/span>17353 65536
<\/span>17369 65536
<\/span>17377 65536
<\/span>17385 65536
<\/span>17393 65536
<\/span>17401 65536
<\/span>17409 65536
<\/span>41865 65536
<\/span>41873 65536
<\/span>41897 65536
<\/span>41905 65536
<\/span>17673 1048576
<\/span>17801 1048576
<\/span>18185 1048576
<\/span>18441 1048576<\/span>
<\/span><\/span><\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

\u3000\u4e00\u3001 1.delete\u4ea7\u751frollback\uff0c\u5982\u679c\u5220\u9664\u5927\u6570\u636e\u91cf\u7684\u8868\u901f\u5ea6\u4f1a\u5f88\u6162\uff0c\u540c … \u7d9a\u304d\u3092\u8aad\u3080 →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6],"tags":[50],"class_list":["post-362","post","type-post","status-publish","format-standard","hentry","category-oracle","tag-oracle-2"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/posts\/362","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/comments?post=362"}],"version-history":[{"count":0,"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/posts\/362\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/media?parent=362"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/categories?post=362"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.rexdf.org\/ja\/wp-json\/wp\/v2\/tags?post=362"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}