{"id":60985,"date":"2024-10-13T07:28:17","date_gmt":"2024-10-12T23:28:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/60985\/"},"modified":"2024-10-13T07:28:17","modified_gmt":"2024-10-12T23:28:17","slug":"db2%e4%b8%ad%e6%9b%b4%e6%96%b0%e5%9f%b7%e8%a1%8c%e8%a8%88%e5%8a%83%e7%9a%84%e5%b9%be%e5%80%8b%e5%b8%b8%e8%a6%8b%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/60985\/","title":{"rendered":"DB2\u4e2d\u66f4\u65b0\u57f7\u884c\u8a08\u5283\u7684\u5e7e\u500b\u5e38\u898b\u7684\u65b9\u6cd5"},"content":{"rendered":"

DB2\u4e2d\u66f4\u65b0\u57f7\u884c\u8a08\u5283\u7684\u5e7e\u500b\u5e38\u898b\u7684\u65b9\u6cd5<\/h1>\n

\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u57f7\u884c\u8a08\u5283\u662f\u6307\u8cc7\u6599\u5eab\u5982\u4f55\u57f7\u884c\u67e5\u8a62\u7684\u5177\u9ad4\u6b65\u9a5f\u3002\u5c0d\u65bcIBM\u7684DB2\u8cc7\u6599\u5eab\u4f86\u8aaa\uff0c\u66f4\u65b0\u57f7\u884c\u8a08\u5283\u662f\u78ba\u4fdd\u67e5\u8a62\u6548\u80fd\u7684\u95dc\u9375\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u500b\u5e38\u898b\u7684\u65b9\u6cd5\u4f86\u66f4\u65b0DB2\u4e2d\u7684\u57f7\u884c\u8a08\u5283\u3002<\/p>\n

1. \u4f7f\u7528RUNSTATS\u547d\u4ee4<\/h2>\n

RUNSTATS\u547d\u4ee4\u662fDB2\u4e2d\u6700\u5e38\u7528\u7684\u66f4\u65b0\u57f7\u884c\u8a08\u5283\u7684\u65b9\u6cd5\u4e4b\u4e00\u3002\u5b83\u7684\u4e3b\u8981\u529f\u80fd\u662f\u6536\u96c6\u8868\u548c\u7d22\u5f15\u7684\u7d71\u8a08\u8cc7\u8a0a\uff0c\u9019\u4e9b\u8cc7\u8a0a\u5c0d\u65bc\u67e5\u8a62\u512a\u5316\u5668\u4f86\u8aaa\u81f3\u95dc\u91cd\u8981\u3002\u7576\u8cc7\u6599\u8868\u4e2d\u7684\u6578\u64da\u767c\u751f\u8b8a\u5316\u6642\uff0c\u57f7\u884c\u8a08\u5283\u53ef\u80fd\u6703\u8b8a\u5f97\u4e0d\u518d\u6709\u6548\uff0c\u56e0\u6b64\u5b9a\u671f\u57f7\u884cRUNSTATS\u662f\u5fc5\u8981\u7684\u3002<\/p>\n

RUNSTATS ON TABLE your_table_name;<\/code><\/pre>\n
\u9019\u689d\u547d\u4ee4\u5c07\u6703\u66f4\u65b0\u6307\u5b9a\u8868\u7684\u7d71\u8a08\u8cc7\u8a0a\u3002\u53ef\u4ee5\u4f7f\u7528\u4e0d\u540c\u7684\u9078\u9805\u4f86\u6307\u5b9a\u8981\u6536\u96c6\u7684\u7d71\u8a08\u8cc7\u8a0a\u985e\u578b\uff0c\u4f8b\u5982\uff1a<\/p>\n
RUNSTATS ON TABLE your_table_name WITH DISTRIBUTION AND DETAILED;<\/code><\/pre>\n
2. \u4f7f\u7528REOPT\u9078\u9805<\/h2>\n
\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u53ef\u80fd\u9700\u8981\u6839\u64da\u57f7\u884c\u6642\u7684\u53c3\u6578\u9032\u884c\u8abf\u6574\u3002DB2\u63d0\u4f9b\u4e86REOPT\u9078\u9805\uff0c\u5141\u8a31\u67e5\u8a62\u5728\u57f7\u884c\u6642\u91cd\u65b0\u8a08\u7b97\u57f7\u884c\u8a08\u5283\u3002\u9019\u5c0d\u65bc\u90a3\u4e9b\u4f9d\u8cf4\u65bc\u8b8a\u91cf\u7684\u67e5\u8a62\u7279\u5225\u6709\u7528\u3002<\/p>\n
SELECT * FROM your_table_name WHERE your_column = ? WITH REOPT;<\/code><\/pre>\n
\u4f7f\u7528REOPT\u9078\u9805\u53ef\u4ee5\u4f7f\u67e5\u8a62\u5728\u57f7\u884c\u6642\u6839\u64da\u7576\u524d\u7684\u53c3\u6578\u503c\u751f\u6210\u6700\u4f73\u7684\u57f7\u884c\u8a08\u5283\u3002<\/p>\n
3. \u4f7f\u7528OPTIMIZE FOR\u5b50\u53e5<\/h2>\n
OPTIMIZE FOR\u5b50\u53e5\u5141\u8a31\u958b\u767c\u8005\u6307\u5b9a\u67e5\u8a62\u512a\u5316\u5668\u5728\u751f\u6210\u57f7\u884c\u8a08\u5283\u6642\u61c9\u8003\u616e\u7684\u53c3\u6578\u503c\u3002\u9019\u5c0d\u65bc\u90a3\u4e9b\u5728\u7279\u5b9a\u7bc4\u570d\u5167\u57f7\u884c\u7684\u67e5\u8a62\u7279\u5225\u6709\u7528\u3002<\/p>\n
SELECT * FROM your_table_name WHERE your_column = ? OPTIMIZE FOR 10 ROWS;<\/code><\/pre>\n
\u9019\u689d\u547d\u4ee4\u544a\u8a34DB2\u512a\u5316\u5668\uff0c\u67e5\u8a62\u7684\u76ee\u6a19\u662f\u8fd4\u56de\u5927\u7d0410\u884c\u6578\u64da\uff0c\u5f9e\u800c\u751f\u6210\u66f4\u5408\u9069\u7684\u57f7\u884c\u8a08\u5283\u3002<\/p>\n
4. \u4f7f\u7528ALTER TABLE\u547d\u4ee4<\/h2>\n
\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u5c0d\u8868\u7d50\u69cb\u7684\u66f4\u6539\u53ef\u80fd\u6703\u5f71\u97ff\u57f7\u884c\u8a08\u5283\u3002\u4f7f\u7528ALTER TABLE\u547d\u4ee4\u53ef\u4ee5\u5f37\u5236DB2\u91cd\u65b0\u8a08\u7b97\u57f7\u884c\u8a08\u5283\u3002\u9019\u5728\u9032\u884c\u5927\u898f\u6a21\u6578\u64da\u9077\u79fb\u6216\u7d50\u69cb\u8abf\u6574\u5f8c\u7279\u5225\u6709\u7528\u3002<\/p>\n
ALTER TABLE your_table_name ALTER COLUMN your_column_name SET DATA TYPE VARCHAR(255);<\/code><\/pre>\n
\u9019\u6a23\u7684\u64cd\u4f5c\u6703\u5c0e\u81f4DB2\u91cd\u65b0\u8a55\u4f30\u8a72\u8868\u7684\u57f7\u884c\u8a08\u5283\u3002<\/p>\n
5. \u4f7f\u7528DB2\u7684\u81ea\u52d5\u7dad\u8b77\u529f\u80fd<\/h2>\n
DB2\u63d0\u4f9b\u4e86\u4e00\u4e9b\u81ea\u52d5\u7dad\u8b77\u529f\u80fd\uff0c\u53ef\u4ee5\u5b9a\u671f\u66f4\u65b0\u7d71\u8a08\u8cc7\u8a0a\u548c\u57f7\u884c\u8a08\u5283\u3002\u9019\u4e9b\u529f\u80fd\u53ef\u4ee5\u901a\u904eDB2\u7684\u7ba1\u7406\u5de5\u5177\u9032\u884c\u914d\u7f6e\uff0c\u78ba\u4fdd\u8cc7\u6599\u5eab\u5728\u904b\u884c\u904e\u7a0b\u4e2d\u4fdd\u6301\u6700\u4f73\u6548\u80fd\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u66f4\u65b0DB2\u4e2d\u7684\u57f7\u884c\u8a08\u5283\u662f\u78ba\u4fdd\u67e5\u8a62\u6548\u80fd\u7684\u95dc\u9375\u6b65\u9a5f\u3002\u901a\u904e\u4f7f\u7528RUNSTATS\u547d\u4ee4\u3001REOPT\u9078\u9805\u3001OPTIMIZE FOR\u5b50\u53e5\u3001ALTER TABLE\u547d\u4ee4\u4ee5\u53caDB2\u7684\u81ea\u52d5\u7dad\u8b77\u529f\u80fd\uff0c\u8cc7\u6599\u5eab\u7ba1\u7406\u54e1\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u548c\u512a\u5316\u57f7\u884c\u8a08\u5283\u3002\u9019\u4e9b\u65b9\u6cd5\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u6548\u80fd\uff0c\u9084\u80fd\u78ba\u4fdd\u8cc7\u6599\u5eab\u5728\u9762\u5c0d\u4e0d\u65b7\u8b8a\u5316\u7684\u6578\u64da\u74b0\u5883\u6642\u4fdd\u6301\u7a69\u5b9a\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 \u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u8cc7\u6599\u5eab\u7ba1\u7406\u9084\u662f\u5176\u4ed6\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684 \u4f3a\u670d\u5668<\/a> \u5c07\u6709\u52a9\u65bc\u63d0\u5347\u60a8\u7684\u696d\u52d9\u6548\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22DB2\u4e2d\u66f4\u65b0\u57f7\u884c\u8a08\u5283\u7684\u5e38\u898b\u65b9\u6cd5\uff0c\u63d0\u5347\u67e5\u8a62\u6027\u80fd\uff0c\u512a\u5316\u6578\u64da\u5eab\u7ba1\u7406\uff0c\u78ba\u4fdd\u9ad8\u6548\u904b\u884c\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-60985","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60985","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=60985"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60985\/revisions"}],"predecessor-version":[{"id":60986,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60985\/revisions\/60986"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=60985"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=60985"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=60985"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}