{"id":736,"date":"2012-04-09T23:52:25","date_gmt":"2012-04-09T15:52:25","guid":{"rendered":"https:\/\/yangtingkun.net\/?p=736"},"modified":"2012-04-12T23:53:31","modified_gmt":"2012-04-12T15:53:31","slug":"%e8%b0%83%e9%ab%98scn%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/yangtingkun.net\/?p=736","title":{"rendered":"\u8c03\u9ad8SCN\u7684\u65b9\u6cd5"},"content":{"rendered":"<p>\u6709\u7684\u65f6\u5019\u51fa\u4e8e\u6062\u590d\u6216\u5176\u4ed6\u76ee\u7684\u7684\u9700\u8981\uff0c\u9700\u8981\u5c06\u73b0\u6709\u7684SCN\u63d0\u5347\u3002<\/p>\n<p>\u572810g\u4ee5\u524d\uff0c\u4e00\u822c\u4f7f\u7528event\u7684\u65b9\u5f0f\uff1a<\/p>\n<pre lang='SQL'>SQL> alter session set events '10015 trace name adjust_scn level 1'; \r\nSession altered.<\/pre>\n<p>\u5728MOUNT\u72b6\u6001\u4e0b\u8fd0\u884c\u4e0a\u9762\u7684SQL\uff0c\u53ef\u4ee5\u6839\u636e\u8c03\u6574SCN\u7684\u9700\u8981\u8bbe\u7f6e\u4e0d\u540c\u7684LEVEL\u3002\u6b64\u5916\u8fd8\u5b58\u5728\u7c7b\u4f3c\u7684\u65b9\u6cd5\uff1a<\/p>\n<pre lang='SQL'>alter system set events 'immediate trace name adjust_scn level 10;<\/pre>\n<p>\u9664\u4e86EVENT\u7684\u8bbe\u7f6e\u5916\uff0c\u8fd8\u6709\u4e00\u4e2a\u9690\u85cf\u53c2\u6570\u4e5f\u53ef\u4ee5\u8f7b\u6613\u7684\u8fbe\u5230\u76ee\u6807\u3002\u4f7f\u7528_minimum_giga_scn\u53c2\u6570\uff0c\u53ef\u4ee5\u5c06SCN\u63d0\u9ad81G\u7684\u500d\u6570\uff1a<\/p>\n<pre lang='SQL'>SQL> select current_scn from v$database;\r\nCURRENT_SCN\r\n-----------\r\n    5310856\r\nSQL> alter system set \"_minimum_giga_scn\" = 1 scope = spfile;\r\nSystem altered.\r\nSQL> shutdown immediate\r\nDatabase closed.\r\nDatabase dismounted.\r\nORACLE instance shut down.\r\nSQL> startup\r\nORACLE instance started.\r\nTotal System Global Area  524288000 bytes\r\nFixed Size                  2097560 bytes\r\nVariable Size             150998632 bytes\r\nDatabase Buffers          369098752 bytes\r\nRedo Buffers                2093056 bytes\r\nDatabase mounted.\r\nDatabase opened.\r\nSQL> select current_scn from v$database;\r\nCURRENT_SCN\r\n-----------\r\n 1073741909\r\nSQL> select * from v$version;\r\nBANNER\r\n----------------------------------------------------------------\r\nOracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi\r\nPL\/SQL Release 10.2.0.5.0 - Production\r\nCORE    10.2.0.5.0      Production\r\nTNS for Linux: Version 10.2.0.5.0 - Production\r\nNLSRTL Version 10.2.0.5.0 - Production<\/pre>\n<p>\u4f7f\u7528\u8fd9\u79cd\u65b9\u6cd5\uff0c\u5c31\u53ef\u4ee5\u8f7b\u6613\u7684\u63d0\u5347SCN\u5230\u6307\u5b9a\u5927\u5c0f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6709\u7684\u65f6\u5019\u51fa\u4e8e\u6062\u590d\u6216\u5176\u4ed6\u76ee\u7684\u7684\u9700\u8981\uff0c\u9700\u8981\u5c06\u73b0\u6709\u7684SCN\u63d0\u5347\u3002 \u572810g\u4ee5\u524d\uff0c\u4e00\u822c\u4f7f\u7528event\u7684\u65b9\u5f0f\uff1a SQL> alter session set events &#8216;10015 trace name adjust_scn level 1&#8217;; Session altered. \u5728MOUNT\u72b6\u6001\u4e0b\u8fd0\u884c\u4e0a\u9762\u7684SQL\uff0c\u53ef\u4ee5\u6839\u636e\u8c03\u6574SCN\u7684\u9700\u8981\u8bbe\u7f6e\u4e0d\u540c\u7684LEVEL\u3002\u6b64\u5916\u8fd8\u5b58\u5728\u7c7b\u4f3c\u7684\u65b9\u6cd5\uff1a alter system set events &#8216;immediate trace name adjust_scn level 10; \u9664\u4e86EVENT\u7684\u8bbe\u7f6e\u5916\uff0c\u8fd8\u6709\u4e00\u4e2a\u9690\u85cf\u53c2\u6570\u4e5f\u53ef\u4ee5\u8f7b\u6613\u7684\u8fbe\u5230\u76ee\u6807\u3002\u4f7f\u7528_minimum_giga_scn\u53c2\u6570\uff0c\u53ef\u4ee5\u5c06SCN\u63d0\u9ad81G\u7684\u500d\u6570\uff1a SQL> select current_scn from v$database; CURRENT_SCN &#8212;&#8212;&#8212;&#8211; 5310856 SQL> alter system set &#8220;_minimum_giga_scn&#8221; &hellip; <a href=\"https:\/\/yangtingkun.net\/?p=736\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[615,614,601,613],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2yiY3-bS","_links":{"self":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts\/736"}],"collection":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=736"}],"version-history":[{"count":1,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts\/736\/revisions"}],"predecessor-version":[{"id":737,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts\/736\/revisions\/737"}],"wp:attachment":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=736"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=736"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=736"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}