\u4e00\u3001\u8868\u7684\u7ee7\u627f\uff1a<\/p>\n
\u8fd9\u4e2a\u6982\u5ff5\u5bf9\u4e8e\u5f88\u591a\u5df2\u7ecf\u719f\u6089\u5176\u4ed6\u6570\u636e\u5e93\u7f16\u7a0b\u7684\u5f00\u53d1\u4eba\u5458\u800c\u8a00\u4f1a\u591a\u5c11\u6709\u4e9b\u964c\u751f\uff0c\u7136\u800c\u5b83\u7684\u5b9e\u73b0\u65b9\u5f0f\u548c\u8bbe\u8ba1\u539f\u7406\u5374\u662f\u7b80\u5355\u6613\u61c2\uff0c\u73b0\u5728\u5c31\u8ba9\u6211\u4eec\u4ece\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\u5f00\u59cb\u5427\u3002\n1. \u7b2c\u4e00\u4e2a\u7ee7\u627f\u8868\uff1a\nCREATE TABLE cities ( --\u7236\u8868\n name text,\n population float,\n altitude int\n);\nCREATE TABLE capitals ( --\u5b50\u8868\n state char(2)\n) INHERITS (cities);\ncapitals\u8868\u7ee7\u627f\u81eacities\u8868\u7684\u6240\u6709\u5c5e\u6027\u3002\u5728PostgreSQL\u91cc\uff0c\u4e00\u4e2a\u8868\u53ef\u4ee5\u4ece\u96f6\u4e2a\u6216\u591a\u4e2a\u5176\u5b83\u8868\u4e2d\u7ee7\u627f\u5c5e\u6027\uff0c\u800c\u4e14\u4e00\u4e2a\u67e5\u8be2\u65e2\u53ef\u4ee5\u5f15\u7528\u7236\u8868\u4e2d\u7684\u6240\u6709\u884c\uff0c\u4e5f\u53ef\u4ee5\u5f15\u7528\u7236\u8868\u7684\u6240\u6709\u884c\u52a0\u4e0a\u5176\u6240\u6709\u5b50\u8868\u7684\u884c\uff0c\u5176\u4e2d\u540e\u8005\u662f\u7f3a\u7701\u884c\u4e3a\u3002\nMyTest=# INSERT INTO cities values('Las Vegas', 1.53, 2174); --\u63d2\u5165\u7236\u8868\nINSERT 0 1\nMyTest=# INSERT INTO cities values('Mariposa',3.30,1953); --\u63d2\u5165\u7236\u8868\nINSERT 0 1\nMyTest=# INSERT INTO capitals values('Madison',4.34,845,'WI');--\u63d2\u5165\u5b50\u8868\nINSERT 0 1\nMyTest=# SELECT name, altitude FROM cities WHERE altitude > 500; --\u7236\u8868\u548c\u5b50\u8868\u7684\u6570\u636e\u5747\u88ab\u53d6\u51fa\u3002\n name | altitude\n-----------+----------\n Las Vegas | 2174\n Mariposa | 1953\n Madison | 845\n(3 rows)\n\nMyTest=# SELECT name, altitude FROM capitals WHERE altitude > 500; --\u53ea\u6709\u5b50\u8868\u7684\u6570\u636e\u88ab\u53d6\u51fa\u3002\n name | altitude\n---------+----------\n Madison | 845\n(1 row)\n\n\u5982\u679c\u5e0c\u671b\u53ea\u4ece\u7236\u8868\u4e2d\u63d0\u53d6\u6570\u636e\uff0c\u5219\u9700\u8981\u5728SQL\u4e2d\u52a0\u5165ONLY\u5173\u952e\u5b57\uff0c\u5982\uff1a\nMyTest=# SELECT name,altitude FROM ONLY cities WHERE altitude > 500;\n name | altitude\n-----------+----------\n Las Vegas | 2174\n Mariposa | 1953\n(2 rows)\n\u4e0a\u4f8b\u4e2dcities\u524d\u9762\u7684\"ONLY\"\u5173\u952e\u5b57\u8868\u793a\u8be5\u67e5\u8be2\u5e94\u8be5\u53ea\u5bf9cities\u8fdb\u884c\u67e5\u627e\u800c\u4e0d\u5305\u62ec\u7ee7\u627f\u7ea7\u522b\u4f4e\u4e8ecities\u7684\u8868\u3002\u8bb8\u591a\u6211\u4eec\u5df2\u7ecf\u8ba8\u8bba\u8fc7\u7684\u547d\u4ee4--SELECT\uff0cUPDATE\u548cDELETE--\u652f\u6301\u8fd9\u4e2a\"ONLY\"\u7b26\u53f7\u3002\n\u5728\u6267\u884c\u6574\u8868\u6570\u636e\u5220\u9664\u65f6\uff0c\u5982\u679c\u76f4\u63a5truncate\u7236\u8868\uff0c\u6b64\u65f6\u7236\u8868\u548c\u5176\u6240\u6709\u5b50\u8868\u7684\u6570\u636e\u5747\u88ab\u5220\u9664\uff0c\u5982\u679c\u53ea\u662ftruncate\u5b50\u8868\uff0c\u90a3\u4e48\u5176\u7236\u8868\u7684\u6570\u636e\u5c06\u4e0d\u4f1a\u53d8\u5316\uff0c\u53ea\u662f\u5b50\u8868\u4e2d\u7684\u6570\u636e\u88ab\u6e05\u7a7a\u3002\nMyTest=# TRUNCATE TABLE cities; --\u7236\u8868\u548c\u5b50\u8868\u7684\u6570\u636e\u5747\u88ab\u5220\u9664\u3002\nTRUNCATE TABLE\nMyTest=# SELECT * FROM capitals;\n name | population | altitude | state\n------+------------+----------+-------\n(0 rows)\n\n2. \u786e\u5b9a\u6570\u636e\u6765\u6e90\uff1a\n\u6709\u65f6\u5019\u4f60\u53ef\u80fd\u60f3\u77e5\u9053\u67d0\u6761\u8bb0\u5f55\u6765\u81ea\u54ea\u4e2a\u8868\u3002\u5728\u6bcf\u4e2a\u8868\u91cc\u6211\u4eec\u90fd\u6709\u4e00\u4e2a\u7cfb\u7edf\u9690\u542b\u5b57\u6bb5tableoid\uff0c\u5b83\u53ef\u4ee5\u544a\u8bc9\u4f60\u8868\u7684\u6765\u6e90\uff1a\nMyTest=# SELECT tableoid, name, altitude FROM cities WHERE altitude > 500;\n tableoid | name | altitude\n----------+-----------+----------\n 16532 | Las Vegas | 2174\n 16532 | Mariposa | 1953\n 16538 | Madison | 845\n(3 rows)\n\u4ee5\u4e0a\u7684\u7ed3\u679c\u53ea\u662f\u7ed9\u51fa\u4e86tableoid\uff0c\u4ec5\u4ec5\u901a\u8fc7\u8be5\u503c\uff0c\u6211\u4eec\u8fd8\u662f\u65e0\u6cd5\u770b\u51fa\u5b9e\u9645\u7684\u8868\u540d\u3002\u8981\u5b8c\u6210\u6b64\u64cd\u4f5c\uff0c\u6211\u4eec\u5c31\u9700\u8981\u548c\u7cfb\u7edf\u8868pg_class\u8fdb\u884c\u5173\u8054\uff0c\u4ee5\u901a\u8fc7tableoid\u5b57\u6bb5\u4ece\u8be5\u8868\u4e2d\u63d0\u53d6\u5b9e\u9645\u7684\u8868\u540d\uff0c\u89c1\u4ee5\u4e0b\u67e5\u8be2\uff1a\nMyTest=# SELECT p.relname, c.name, c.altitude FROM cities c,pg_class p WHERE c.altitude > 500 and c.tableoid = p.oid;\n relname | name | altitude\n----------+-----------+----------\n cities | Las Vegas | 2174\n cities | Mariposa | 1953\n capitals | Madison | 845\n(3 rows)\n\n3. \u6570\u636e\u63d2\u5165\u7684\u6ce8\u610f\u4e8b\u9879\uff1a\n\u7ee7\u627f\u5e76\u4e0d\u81ea\u52a8\u4eceINSERT\u6216\u8005COPY\u4e2d\u5411\u7ee7\u627f\u7ea7\u522b\u4e2d\u7684\u5176\u5b83\u8868\u586b\u5145\u6570\u636e\u3002\u5728\u6211\u4eec\u7684\u4f8b\u5b50\u91cc\uff0c\u4e0b\u9762\u7684INSERT\u8bed\u53e5\u4e0d\u4f1a\u6210\u529f\uff1a\nINSERT INTO cities (name, population, altitude, state) VALUES ('New York', NULL, NULL, 'NY');\n\u6211\u4eec\u53ef\u80fd\u5e0c\u671b\u6570\u636e\u88ab\u4f20\u9012\u5230capitals\u8868\u91cc\u9762\u53bb\uff0c\u4f46\u662f\u8fd9\u662f\u4e0d\u4f1a\u53d1\u751f\u7684\uff1aINSERT\u603b\u662f\u63d2\u5165\u660e\u786e\u58f0\u660e\u7684\u90a3\u4e2a\u8868\u3002\n\n4. \u591a\u8868\u7ee7\u627f\uff1a\n\u4e00\u4e2a\u8868\u53ef\u4ee5\u4ece\u591a\u4e2a\u7236\u8868\u7ee7\u627f\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\u5b83\u62e5\u6709\u7236\u8868\u4eec\u7684\u5b57\u6bb5\u7684\u603b\u548c\u3002\u5b50\u8868\u4e2d\u4efb\u610f\u5b9a\u4e49\u7684\u5b57\u6bb5\u4e5f\u4f1a\u52a0\u5165\u5176\u4e2d\u3002\u5982\u679c\u540c\u4e00\u4e2a\u5b57\u6bb5\u540d\u51fa\u73b0\u5728\u591a\u4e2a\u7236\u8868\u4e2d\uff0c\u6216\u8005\u540c\u65f6\u51fa\u73b0\u5728\u7236\u8868\u548c\u5b50\u8868\u7684\u5b9a\u4e49\u91cc\uff0c\u90a3\u4e48\u8fd9\u4e9b\u5b57\u6bb5\u5c31\u4f1a\u88ab\"\u878d\u5408\"\uff0c\u8fd9\u6837\u5728\u5b50\u8868\u91cc\u9762\u5c31\u53ea\u6709\u4e00\u4e2a\u8fd9\u6837\u7684\u5b57\u6bb5\u3002\u8981\u60f3\u878d\u5408\uff0c\u5b57\u6bb5\u5fc5\u987b\u662f\u76f8\u540c\u7684\u6570\u636e\u7c7b\u578b\uff0c\u5426\u5219\u5c31\u4f1a\u629b\u51fa\u4e00\u4e2a\u9519\u8bef\u3002\u878d\u5408\u7684\u5b57\u6bb5\u5c06\u4f1a\u62e5\u6709\u5b83\u6240\u7ee7\u627f\u7684\u5b57\u6bb5\u7684\u6240\u6709\u7ea6\u675f\u3002\nCREATE TABLE parent1 (FirstCol integer);\nCREATE TABLE parent2 (FirstCol integer, SecondCol varchar(20));\nCREATE TABLE parent3 (FirstCol varchar(200)); \n--\u5b50\u8868child1\u5c06\u540c\u65f6\u7ee7\u627f\u81eaparent1\u548cparent2\u8868\uff0c\u800c\u8fd9\u4e24\u4e2a\u7236\u8868\u4e2d\u5747\u5305\u542binteger\u7c7b\u578b\u7684FirstCol\u5b57\u6bb5\uff0c\u56e0\u6b64child1\u53ef\u4ee5\u521b\u5efa\u6210\u529f\u3002\nCREATE TABLE child1 (MyCol timestamp) INHERITS (parent1,parent2);\n--\u5b50\u8868child2\u5c06\u4e0d\u4f1a\u521b\u5efa\u6210\u529f\uff0c\u56e0\u4e3a\u5176\u4e24\u4e2a\u7236\u8868\u4e2d\u5747\u5305\u542bFirstCol\u5b57\u6bb5\uff0c\u4f46\u662f\u5b83\u4eec\u7684\u7c7b\u578b\u4e0d\u76f8\u540c\u3002\nCREATE TABLE child2 (MyCol timestamp) INHERITS (parent1,parent3);\n--\u5b50\u8868child3\u540c\u6837\u4e0d\u4f1a\u521b\u5efa\u6210\u529f\uff0c\u56e0\u4e3a\u5b83\u548c\u5176\u7236\u8868\u5747\u5305\u542bFirstCol\u5b57\u6bb5\uff0c\u4f46\u662f\u5b83\u4eec\u7684\u7c7b\u578b\u4e0d\u76f8\u540c\u3002\nCREATE TABLE child3 (FirstCol varchar(20)) INHERITS(parent1);\n\n5. \u7ee7\u627f\u548c\u6743\u9650\uff1a\n\u8868\u8bbf\u95ee\u6743\u9650\u5e76\u4e0d\u4f1a\u81ea\u52a8\u7ee7\u627f\u3002\u56e0\u6b64\uff0c\u4e00\u4e2a\u8bd5\u56fe\u8bbf\u95ee\u7236\u8868\u7684\u7528\u6237\u8fd8\u5fc5\u987b\u5177\u6709\u8bbf\u95ee\u5b83\u7684\u6240\u6709\u5b50\u8868\u7684\u6743\u9650\uff0c\u6216\u8005\u4f7f\u7528ONLY\u5173\u952e\u5b57\u53ea\u4ece\u7236\u8868\u4e2d\u63d0\u53d6\u6570\u636e\u3002\u5728\u5411\u73b0\u6709\u7684\u7ee7\u627f\u5c42\u6b21\u6dfb\u52a0\u65b0\u7684\u5b50\u8868\u7684\u65f6\u5019\uff0c\u8bf7\u6ce8\u610f\u7ed9\u5b83\u8d4b\u4e88\u6240\u6709\u6743\u9650\u3002 \n\u7ee7\u627f\u7279\u6027\u7684\u4e00\u4e2a\u4e25\u91cd\u7684\u5c40\u9650\u6027\u662f\u7d22\u5f15(\u5305\u62ec\u552f\u4e00\u7ea6\u675f)\u548c\u5916\u952e\u7ea6\u675f\u53ea\u65bd\u7528\u4e8e\u5355\u4e2a\u8868\uff0c\u800c\u4e0d\u5305\u62ec\u5b83\u4eec\u7684\u7ee7\u627f\u7684\u5b50\u8868\u3002\u8fd9\u4e00\u70b9\u4e0d\u7ba1\u5bf9\u5f15\u7528\u8868\u8fd8\u662f\u88ab\u5f15\u7528\u8868\u90fd\u662f\u4e8b\u5b9e\uff0c\u56e0\u6b64\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u91cc\uff0c\u5982\u679c\u6211\u4eec\u58f0\u660ecities.name\u4e3aUNIQUE\u6216\u8005\u662f\u4e00\u4e2aPRIMARY KEY\uff0c\u90a3\u4e48\u4e5f\u4e0d\u4f1a\u963b\u6b62capitals\u8868\u62e5\u6709\u91cd\u590d\u4e86\u540d\u5b57\u7684cities\u6570\u636e\u884c\u3002 \u5e76\u4e14\u8fd9\u4e9b\u91cd\u590d\u7684\u884c\u7f3a\u7701\u65f6\u5728\u67e5\u8be2cities\u8868\u7684\u65f6\u5019\u4f1a\u663e\u793a\u51fa\u6765\u3002\u5b9e\u9645\u4e0a\uff0c\u7f3a\u7701\u65f6capitals\u5c06\u5b8c\u5168\u6ca1\u6709\u552f\u4e00\u7ea6\u675f\uff0c\u56e0\u6b64\u53ef\u80fd\u5305\u542b\u5e26\u6709\u540c\u540d\u7684\u591a\u4e2a\u884c\u3002\u4f60\u5e94\u8be5\u7ed9capitals\u589e\u52a0\u552f\u4e00\u7ea6\u675f\uff0c\u4f46\u662f\u8fd9\u6837\u505a\u4e5f\u4e0d\u4f1a\u907f\u514d\u4e0ecities\u7684\u91cd\u590d\u3002\u7c7b\u4f3c\uff0c\u5982\u679c\u6211\u4eec\u58f0\u660ecities.name REFERENCES\u67d0\u4e9b\u5176\u5b83\u7684\u8868\uff0c\u8fd9\u4e2a\u7ea6\u675f\u4e0d\u4f1a\u81ea\u52a8\u5e7f\u64ad\u5230capitals\u3002\u5728\u8fd9\u79cd\u6761\u4ef6\u4e0b\uff0c\u4f60\u53ef\u4ee5\u901a\u8fc7\u624b\u5de5\u7ed9capitals \u589e\u52a0\u540c\u6837\u7684REFERENCES\u7ea6\u675f\u6765\u505a\u5230\u8fd9\u70b9\u3002<\/code><\/pre>\n\u4e8c\u3001\u5206\u533a\u8868\uff1a<\/p>\n
1. \u6982\u8ff0\u5206\u533a\u8868\uff1a\n\u5206\u533a\u7684\u610f\u601d\u662f\u628a\u903b\u8f91\u4e0a\u7684\u4e00\u4e2a\u5927\u8868\u5206\u5272\u6210\u7269\u7406\u4e0a\u7684\u51e0\u5757\u513f\uff0c\u5206\u533a\u53ef\u4ee5\u63d0\u4f9b\u82e5\u5e72\u597d\u5904\uff1a\n1). \u67d0\u4e9b\u7c7b\u578b\u7684\u67e5\u8be2\u6027\u80fd\u53ef\u4ee5\u5f97\u5230\u6781\u5927\u63d0\u5347\u3002\n2). \u66f4\u65b0\u7684\u6027\u80fd\u4e5f\u53ef\u4ee5\u5f97\u5230\u63d0\u5347\uff0c\u56e0\u4e3a\u8868\u7684\u6bcf\u5757\u7684\u7d22\u5f15\u8981\u6bd4\u5728\u6574\u4e2a\u6570\u636e\u96c6\u4e0a\u7684\u7d22\u5f15\u8981\u5c0f\u3002\u5982\u679c\u7d22\u5f15\u4e0d\u80fd\u5168\u90e8\u653e\u5728\u5185\u5b58\u91cc\uff0c\u90a3\u4e48\u5728\u7d22\u5f15\u4e0a\u7684\u8bfb\u548c\u5199\u90fd\u4f1a\u4ea7\u751f\u66f4\u591a\u7684\u78c1\u76d8\u8bbf\u95ee\u3002\n3). \u6279\u91cf\u5220\u9664\u53ef\u4ee5\u7528\u7b80\u5355\u5730\u5220\u9664\u67d0\u4e2a\u5206\u533a\u6765\u5b9e\u73b0\u3002\n4). \u5c06\u5f88\u5c11\u7528\u7684\u6570\u636e\u53ef\u4ee5\u79fb\u52a8\u5230\u4fbf\u5b9c\u7684\u3001\u6162\u4e00\u4e9b\u5730\u5b58\u50a8\u4ecb\u8d28\u4e0a\u3002 \n\u5047\u8bbe\u5f53\u524d\u7684\u6570\u636e\u5e93\u5e76\u4e0d\u652f\u6301\u5206\u533a\u8868\uff0c\u800c\u6211\u4eec\u7684\u5e94\u7528\u6240\u9700\u5904\u7406\u7684\u6570\u636e\u91cf\u4e5f\u975e\u5e38\u5927\uff0c\u5bf9\u4e8e\u8fd9\u79cd\u5e94\u7528\u573a\u666f\uff0c\u6211\u4eec\u4e0d\u5f97\u4e0d\u4eba\u4e3a\u7684\u5c06\u8be5\u5927\u8868\u6309\u7167\u4e00\u5b9a\u7684\u89c4\u5219\uff0c\u624b\u5de5\u62c6\u5206\u6210\u591a\u4e2a\u5c0f\u8868\uff0c\u8ba9\u6bcf\u4e2a\u5c0f\u8868\u5305\u542b\u4e0d\u540c\u533a\u95f4\u7684\u6570\u636e\u3002\u8fd9\u6837\u4e00\u6765\uff0c\u6211\u4eec\u5c31\u5fc5\u987b\u5728\u6570\u636e\u63d2\u5165\u3001\u66f4\u65b0\u3001\u5220\u9664\u548c\u67e5\u8be2\u4e4b\u524d\uff0c\u5148\u8ba1\u7b97\u672c\u6b21\u7684\u6307\u4ee4\u9700\u8981\u64cd\u4f5c\u7684\u5c0f\u8868\u3002\u5bf9\u4e8e\u6709\u4e9b\u67e5\u8be2\u800c\u8a00\uff0c\u7531\u4e8e\u67e5\u8be2\u533a\u95f4\u53ef\u80fd\u4f1a\u8de8\u8d8a\u591a\u4e2a\u5c0f\u8868\uff0c\u8fd9\u6837\u6211\u4eec\u53c8\u4e0d\u5f97\u4e0d\u5c06\u591a\u4e2a\u5c0f\u8868\u7684\u67e5\u8be2\u7ed3\u679c\u8fdb\u884cunion\u64cd\u4f5c\uff0c\u4ee5\u5408\u5e76\u6765\u81ea\u591a\u4e2a\u8868\u7684\u6570\u636e\uff0c\u5e76\u6700\u7ec8\u5f62\u6210\u4e00\u4e2a\u7ed3\u679c\u96c6\u8fd4\u56de\u7ed9\u5ba2\u6237\u7aef\u3002\u53ef\u89c1\uff0c\u5982\u679c\u6211\u4eec\u6b63\u5728\u4f7f\u7528\u7684\u6570\u636e\u5e93\u4e0d\u652f\u6301\u5206\u533a\u8868\uff0c\u90a3\u4e48\u5728\u9002\u5408\u5176\u5e94\u7528\u7684\u573a\u666f\u4e0b\uff0c\u6211\u4eec\u5c31\u9700\u8981\u505a\u5f88\u591a\u989d\u5916\u7684\u7f16\u7a0b\u5de5\u4f5c\u4ee5\u5f25\u8865\u8fd9\u4e00\u7f3a\u5931\u3002\u7136\u800c\u9700\u8981\u8bf4\u660e\u7684\u662f\uff0c\u5c3d\u7ba1\u529f\u80fd\u53ef\u4ee5\u52c9\u5f3a\u5e94\u4ed8\uff0c\u4f46\u662f\u6027\u80fd\u5374\u548c\u5206\u533a\u8868\u65e0\u6cd5\u76f8\u63d0\u5e76\u8bba\u3002\n\u76ee\u524dPostgreSQL\u652f\u6301\u7684\u5206\u533a\u5f62\u5f0f\u4e3b\u8981\u4e3a\u4ee5\u4e0b\u4e24\u79cd\uff1a\n1). \u8303\u56f4\u5206\u533a: \u8868\u88ab\u4e00\u4e2a\u6216\u8005\u591a\u4e2a\u952e\u5b57\u5b57\u6bb5\u5206\u533a\u6210\"\u8303\u56f4\"\uff0c\u5728\u8fd9\u4e9b\u8303\u56f4\u4e4b\u95f4\u6ca1\u6709\u91cd\u53e0\u7684\u6570\u503c\u5206\u5e03\u5230\u4e0d\u540c\u7684\u5206\u533a\u91cc\u3002\u6bd4\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u4e3a\u7279\u5b9a\u7684\u5546\u4e1a\u5bf9\u8c61\u6839\u636e\u6570\u636e\u8303\u56f4\u5206\u533a\uff0c\u6216\u8005\u6839\u636e\u6807\u8bc6\u7b26\u8303\u56f4\u5206\u533a\u3002\n2). \u5217\u8868\u5206\u533a: \u8868\u662f\u901a\u8fc7\u660e\u786e\u5730\u5217\u51fa\u6bcf\u4e2a\u5206\u533a\u91cc\u5e94\u8be5\u51fa\u73b0\u90a3\u4e9b\u952e\u5b57\u503c\u5b9e\u73b0\u7684\u3002 \n\n2. \u5b9e\u73b0\u5206\u533a\uff1a\n1). \u521b\u5efa\"\u4e3b\u8868\"\uff0c\u6240\u6709\u5206\u533a\u90fd\u4ece\u5b83\u7ee7\u627f\u3002\nCREATE TABLE measurement ( --\u4e3b\u8868\n city_id int NOT NULL,\n logdate date NOT NULL,\n peaktemp int,\n); \n2). \u521b\u5efa\u51e0\u4e2a\"\u5b50\"\u8868\uff0c\u6bcf\u4e2a\u90fd\u4ece\u4e3b\u8868\u4e0a\u7ee7\u627f\u3002\u901a\u5e38\uff0c\u8fd9\u4e9b\"\u5b50\"\u8868\u5c06\u4e0d\u4f1a\u518d\u589e\u52a0\u4efb\u4f55\u5b57\u6bb5\u3002\u6211\u4eec\u5c06\u628a\u5b50\u8868\u79f0\u4f5c\u5206\u533a\uff0c\u5c3d\u7ba1\u5b83\u4eec\u5c31\u662f\u666e\u901a\u7684PostgreSQL\u8868\u3002\nCREATE TABLE measurement_yy04mm02 ( ) INHERITS (measurement);\nCREATE TABLE measurement_yy04mm03 ( ) INHERITS (measurement);\n...\nCREATE TABLE measurement_yy05mm11 ( ) INHERITS (measurement);\nCREATE TABLE measurement_yy05mm12 ( ) INHERITS (measurement);\nCREATE TABLE measurement_yy06mm01 ( ) INHERITS (measurement);\n\u4e0a\u9762\u521b\u5efa\u7684\u5b50\u8868\uff0c\u5747\u5df2\u5e74\u3001\u6708\u7684\u5f62\u5f0f\u8fdb\u884c\u8303\u56f4\u5212\u5206\uff0c\u4e0d\u540c\u5e74\u6708\u7684\u6570\u636e\u5c06\u5f52\u5c5e\u5230\u4e0d\u540c\u7684\u5b50\u8868\u5185\u3002\u8fd9\u6837\u7684\u5b9e\u73b0\u65b9\u5f0f\u5bf9\u4e8e\u6e05\u7a7a\u5206\u533a\u6570\u636e\u800c\u8a00\u5c06\u6781\u4e3a\u65b9\u4fbf\u548c\u9ad8\u6548\uff0c\u5373\u76f4\u63a5\u6267\u884cDROP TABLE\u8bed\u53e5\u5220\u9664\u76f8\u5e94\u7684\u5b50\u8868\uff0c\u4e4b\u540e\u5728\u6839\u636e\u5b9e\u9645\u7684\u5e94\u7528\u8003\u8651\u662f\u5426\u91cd\u5efa\u8be5\u5b50\u8868(\u5206\u533a)\u3002\u76f8\u6bd4\u4e8e\u76f4\u63a5DROP\u5b50\u8868\uff0cPostgreSQL\u8fd8\u63d0\u4f9b\u4e86\u53e6\u5916\u4e00\u79cd\u66f4\u4e3a\u65b9\u4fbf\u7684\u65b9\u5f0f\u6765\u7ba1\u7406\u5b50\u8868\uff1a\nALTER TABLE measurement_yy06mm01 NO INHERIT measurement;\n\u548c\u76f4\u63a5DROP\u76f8\u6bd4\uff0c\u8be5\u65b9\u5f0f\u4ec5\u4ec5\u662f\u4f7f\u5b50\u8868\u8131\u79bb\u4e86\u539f\u6709\u7684\u4e3b\u8868\uff0c\u800c\u5b58\u50a8\u5728\u5b50\u8868\u4e2d\u7684\u6570\u636e\u4ecd\u7136\u53ef\u4ee5\u5f97\u5230\u8bbf\u95ee\uff0c\u56e0\u4e3a\u6b64\u65f6\u8be5\u8868\u5df2\u7ecf\u88ab\u8fd8\u539f\u6210\u4e00\u4e2a\u666e\u901a\u7684\u6570\u636e\u8868\u4e86\u3002\u8fd9\u6837\u5bf9\u4e8e\u6570\u636e\u5e93\u7684DBA\u6765\u8bf4\uff0c\u5c31\u53ef\u4ee5\u5728\u6b64\u65f6\u5bf9\u8be5\u8868\u8fdb\u884c\u5fc5\u8981\u7684\u7ef4\u62a4\u64cd\u4f5c\uff0c\u5982\u6570\u636e\u6e05\u7406\u3001\u5f52\u6863\u7b49\uff0c\u5728\u5b8c\u6210\u8bf8\u591a\u4f8b\u884c\u6027\u7684\u64cd\u4f5c\u4e4b\u540e\uff0c\u5c31\u53ef\u4ee5\u8003\u8651\u662f\u76f4\u63a5\u5220\u9664\u8be5\u8868(DROP TABLE)\uff0c\u8fd8\u662f\u5148\u6e05\u7a7a\u8be5\u8868\u7684\u6570\u636e(TRUNCATE TABLE)\uff0c\u4e4b\u540e\u518d\u8ba9\u8be5\u8868\u91cd\u65b0\u7ee7\u627f\u4e3b\u8868\uff0c\u5982\uff1a\nALTER TABLE measurement_yy06mm01 INHERIT measurement;\n3). \u7ed9\u5206\u533a\u8868\u589e\u52a0\u7ea6\u675f\uff0c\u5b9a\u4e49\u6bcf\u4e2a\u5206\u533a\u5141\u8bb8\u7684\u5065\u503c\u3002\u540c\u65f6\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5b9a\u4e49\u7684\u7ea6\u675f\u8981\u786e\u4fdd\u5728\u4e0d\u540c\u7684\u5206\u533a\u91cc\u4e0d\u4f1a\u6709\u76f8\u540c\u7684\u952e\u503c\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u9700\u8981\u5c06\u4e0a\u9762\"\u5b50\"\u8868\u7684\u5b9a\u4e49\u4fee\u6539\u4e3a\u4ee5\u4e0b\u5f62\u5f0f\uff1a\nCREATE TABLE measurement_yy04mm02 (\n CHECK ( logdate >= DATE '2004-02-01' AND logdate < DATE '2004-03-01')\n) INHERITS (measurement);\nCREATE TABLE measurement_yy04mm03 (\n CHECK (logdate >= DATE '2004-03-01' AND logdate < DATE '2004-04-01')\n) INHERITS (measurement);\n...\nCREATE TABLE measurement_yy05mm11 (\n CHECK (logdate >= DATE '2005-11-01' AND logdate < DATE '2005-12-01')\n) INHERITS (measurement);\nCREATE TABLE measurement_yy05mm12 (\n CHECK (logdate >= DATE '2005-12-01' AND logdate < DATE '2006-01-01')\n) INHERITS (measurement);\nCREATE TABLE measurement_yy06mm01 (\n CHECK (logdate >= DATE '2006-01-01' AND logdate < DATE '2006-02-01')\n) INHERITS (measurement); \n4). \u5c3d\u53ef\u80fd\u57fa\u4e8e\u952e\u503c\u521b\u5efa\u7d22\u5f15\u3002\u5982\u679c\u9700\u8981\uff0c\u6211\u4eec\u4e5f\u540c\u6837\u53ef\u4ee5\u4e3a\u5b50\u8868\u4e2d\u7684\u5176\u5b83\u5b57\u6bb5\u521b\u5efa\u7d22\u5f15\u3002\nCREATE INDEX measurement_yy04mm02_logdate ON measurement_yy04mm02 (logdate);\nCREATE INDEX measurement_yy04mm03_logdate ON measurement_yy04mm03 (logdate);\n...\nCREATE INDEX measurement_yy05mm11_logdate ON measurement_yy05mm11 (logdate);\nCREATE INDEX measurement_yy05mm12_logdate ON measurement_yy05mm12 (logdate);\nCREATE INDEX measurement_yy06mm01_logdate ON measurement_yy06mm01 (logdate); \n5). \u5b9a\u4e49\u4e00\u4e2a\u89c4\u5219\u6216\u8005\u89e6\u53d1\u5668\uff0c\u628a\u5bf9\u4e3b\u8868\u7684\u4fee\u6539\u91cd\u5b9a\u5411\u5230\u9002\u5f53\u7684\u5206\u533a\u8868\u3002\n\u5982\u679c\u6570\u636e\u53ea\u8fdb\u5165\u6700\u65b0\u7684\u5206\u533a\uff0c\u6211\u4eec\u53ef\u4ee5\u8bbe\u7f6e\u4e00\u4e2a\u975e\u5e38\u7b80\u5355\u7684\u89c4\u5219\u6765\u63d2\u5165\u6570\u636e\u3002\u6211\u4eec\u5fc5\u987b\u6bcf\u4e2a\u6708\u90fd\u91cd\u65b0\u5b9a\u4e49\u8fd9\u4e2a\u89c4\u5219\uff0c\u5373\u4fee\u6539\u91cd\u5b9a\u5411\u63d2\u5165\u7684\u5b50\u8868\u540d\uff0c\u8fd9\u6837\u5b83\u603b\u662f\u6307\u5411\u5f53\u524d\u5206\u533a\u3002\nCREATE OR REPLACE RULE measurement_current_partition AS\nON INSERT TO measurement\nDO INSTEAD\nINSERT INTO measurement_yy06mm01 VALUES (NEW.city_id, NEW.logdate, NEW.peaktemp);\n\u5176\u4e2dNEW\u662f\u5173\u952e\u5b57\uff0c\u8868\u793a\u65b0\u6570\u636e\u5b57\u6bb5\u7684\u96c6\u5408\u3002\u8fd9\u91cc\u53ef\u4ee5\u901a\u8fc7\u70b9(.)\u64cd\u4f5c\u7b26\u6765\u83b7\u53d6\u96c6\u5408\u4e2d\u7684\u6bcf\u4e00\u4e2a\u5b57\u6bb5\u3002\n\u6211\u4eec\u53ef\u80fd\u60f3\u63d2\u5165\u6570\u636e\u5e76\u4e14\u60f3\u8ba9\u670d\u52a1\u5668\u81ea\u52a8\u5b9a\u4f4d\u5e94\u8be5\u5411\u54ea\u4e2a\u5206\u533a\u63d2\u5165\u6570\u636e\u3002\u6211\u4eec\u53ef\u4ee5\u7528\u50cf\u4e0b\u9762\u8fd9\u6837\u7684\u66f4\u590d\u6742\u7684\u89c4\u5219\u96c6\u6765\u5b9e\u73b0\u8fd9\u4e2a\u76ee\u6807\u3002\nCREATE RULE measurement_insert_yy04mm02 AS\nON INSERT TO measurement WHERE (logdate >= DATE '2004-02-01' AND logdate < DATE '2004-03-01')\nDO INSTEAD\nINSERT INTO measurement_yy04mm02 VALUES (NEW.city_id, NEW.logdate, NEW.peaktemp);\n...\nCREATE RULE measurement_insert_yy05mm12 AS\nON INSERT TO measurement WHERE (logdate >= DATE '2005-12-01' AND logdate < DATE '2006-01-01')\nDO INSTEAD\nINSERT INTO measurement_yy05mm12 VALUES (NEW.city_id, NEW.logdate, NEW.peaktemp);\nCREATE RULE measurement_insert_yy06mm01 AS\nON INSERT TO measurement WHERE (logdate >= DATE '2006-01-01' AND logdate < DATE '2006-02-01')\nDO INSTEAD\nINSERT INTO measurement_yy06mm01 VALUES (NEW.city_id, NEW.logdate, NEW.peaktemp); \n\u8bf7\u6ce8\u610f\u6bcf\u4e2a\u89c4\u5219\u91cc\u9762\u7684WHERE\u5b50\u53e5\u6b63\u597d\u5339\u914d\u5176\u5206\u533a\u7684CHECK\u7ea6\u675f\u3002\n\u53ef\u4ee5\u770b\u51fa\uff0c\u4e00\u4e2a\u590d\u6742\u7684\u5206\u533a\u65b9\u6848\u53ef\u80fd\u8981\u6c42\u76f8\u5f53\u591a\u7684DDL\u3002\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u91cc\u6211\u4eec\u9700\u8981\u6bcf\u4e2a\u6708\u521b\u5efa\u4e00\u6b21\u65b0\u5206\u533a\uff0c\u56e0\u6b64\u5199\u4e00\u4e2a\u811a\u672c\u81ea\u52a8\u751f\u6210\u9700\u8981\u7684DDL\u662f\u660e\u667a\u7684\u3002\u9664\u6b64\u4e4b\u5916\uff0c\u6211\u4eec\u8fd8\u4e0d\u96be\u63a8\u65ad\u51fa\uff0c\u5206\u533a\u8868\u5bf9\u4e8e\u65b0\u6570\u636e\u7684\u6279\u91cf\u63d2\u5165\u64cd\u4f5c\u6709\u4e00\u5b9a\u7684\u6291\u5236\uff0c\u8fd9\u4e00\u70b9\u5728Oracle\u4e2d\u4e5f\u540c\u6837\u5982\u6b64\u3002 \n\u9664\u4e86\u4e0a\u9762\u4ecb\u7ecd\u7684\u901a\u8fc7Rule\u7684\u65b9\u5f0f\u91cd\u5b9a\u5411\u4e3b\u8868\u7684\u6570\u636e\u5230\u5404\u4e2a\u5b50\u8868\uff0c\u6211\u4eec\u8fd8\u53ef\u4ee5\u901a\u8fc7\u89e6\u53d1\u5668\u7684\u65b9\u5f0f\u6765\u5b8c\u6210\u6b64\u64cd\u4f5c\uff0c\u76f8\u6bd4\u4e8e\u57fa\u4e8eRule\u7684\u91cd\u5b9a\u5411\u65b9\u6cd5\uff0c\u57fa\u4e8e\u89e6\u53d1\u5668\u7684\u65b9\u5f0f\u53ef\u80fd\u4f1a\u5e26\u6765\u66f4\u597d\u7684\u63d2\u5165\u6548\u7387\uff0c\u7279\u522b\u662f\u9488\u5bf9\u975e\u6279\u91cf\u63d2\u5165\u7684\u60c5\u51b5\u3002\u7136\u800c\u5bf9\u4e8e\u6279\u91cf\u63d2\u5165\u800c\u8a00\uff0c\u7531\u4e8eRule\u7684\u989d\u5916\u5f00\u9500\u662f\u57fa\u4e8e\u8868\u7684\uff0c\u800c\u4e0d\u662f\u57fa\u4e8e\u884c\u7684\uff0c\u56e0\u6b64\u6548\u679c\u4f1a\u597d\u4e8e\u89e6\u53d1\u5668\u65b9\u5f0f\u3002\u53e6\u4e00\u4e2a\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0ccopy\u64cd\u4f5c\u5c06\u4f1a\u5ffd\u7565Rules\uff0c\u5982\u679c\u6211\u4eec\u60f3\u8981\u901a\u8fc7COPY\u65b9\u6cd5\u6765\u63d2\u5165\u6570\u636e\uff0c\u4f60\u53ea\u80fd\u5c06\u6570\u636e\u76f4\u63a5copy\u5230\u6b63\u786e\u7684\u5b50\u8868\uff0c\u800c\u4e0d\u662f\u4e3b\u8868\u3002\u8fd9\u79cd\u9650\u5236\u5bf9\u4e8e\u89e6\u53d1\u5668\u6765\u8bf4\u662f\u4e0d\u4f1a\u9020\u6210\u4efb\u4f55\u95ee\u9898\u7684\u3002\u57fa\u4e8eRule\u7684\u91cd\u5b9a\u5411\u65b9\u5f0f\u8fd8\u5b58\u5728\u53e6\u5916\u4e00\u4e2a\u95ee\u9898\uff0c\u5c31\u662f\u5f53\u63d2\u5165\u7684\u6570\u636e\u4e0d\u5728\u4efb\u4f55\u5b50\u8868\u7684\u7ea6\u675f\u4e2d\u65f6\uff0cPostgreSQL\u4e5f\u4e0d\u4f1a\u62a5\u9519\uff0c\u800c\u662f\u5c06\u6570\u636e\u76f4\u63a5\u4fdd\u7559\u5728\u4e3b\u8868\u4e2d\u3002\n6). \u6dfb\u52a0\u65b0\u5206\u533a\uff1a\n\u8fd9\u91cc\u5c06\u4ecb\u7ecd\u4e24\u79cd\u6dfb\u52a0\u65b0\u5206\u533a\u7684\u65b9\u5f0f\uff0c\u7b2c\u4e00\u79cd\u65b9\u6cd5\u7b80\u5355\u4e14\u76f4\u89c2\uff0c\u6211\u4eec\u53ea\u662f\u521b\u5efa\u65b0\u7684\u5b50\u8868\uff0c\u540c\u65f6\u4e3a\u5176\u5b9a\u4e49\u65b0\u7684\u68c0\u67e5\u7ea6\u675f\uff0c\u5982\uff1a\nCREATE TABLE measurement_y2008m02 (\n CHECK ( logdate >= DATE '2008-02-01' AND logdate < DATE '2008-03-01' )\n) INHERITS (measurement);\n\u7b2c\u4e8c\u79cd\u65b9\u6cd5\u7684\u521b\u5efa\u6b65\u9aa4\u76f8\u5bf9\u7e41\u7410\uff0c\u4f46\u66f4\u4e3a\u7075\u6d3b\u548c\u5b9e\u7528\u3002\u89c1\u4ee5\u4e0b\u56db\u6b65\uff1a\n\/* \u521b\u5efa\u4e00\u4e2a\u72ec\u7acb\u7684\u6570\u636e\u8868(measurement_y2008m02)\uff0c\u8be5\u8868\u5728\u521b\u5efa\u65f6\u4ee5\u5c06\u6765\u7684\u4e3b\u8868(measurement)\u4e3a\u6a21\u677f\uff0c\u5305\u542b\u6a21\u677f\u8868\u7684\u7f3a\u7701\u503c(DEFAULTS)\u548c\u4e00\u81f4\u6027\u7ea6\u675f(CONSTRAINTS)\u3002*\/\nCREATE TABLE measurement_y2008m02\n (LIKE measurement INCLUDING DEFAULTS INCLUDING CONSTRAINTS);\n\/* \u4e3a\u8be5\u8868\u521b\u5efa\u672a\u6765\u4f5c\u4e3a\u5b50\u8868\u65f6\u9700\u8981\u4f7f\u7528\u7684\u68c0\u67e5\u7ea6\u675f\u3002*\/\nALTER TABLE measurement_y2008m02 ADD CONSTRAINT y2008m02\n CHECK (logdate >= DATE '2008-02-01' AND logdate < DATE '2008-03-01');\n\/* \u5bfc\u5165\u6570\u636e\u5230\u8be5\u8868\u3002\u4e0b\u9762\u53ea\u662f\u7ed9\u51fa\u4e00\u79cd\u5bfc\u5165\u6570\u636e\u7684\u65b9\u5f0f\u4f5c\u4e3a\u4f8b\u5b50\u3002\u5728\u5bfc\u5165\u6570\u636e\u4e4b\u540e\uff0c\u5982\u6709\u53ef\u80fd\uff0c\u8fd8\u53ef\u4ee5\u505a\u8fdb\u4e00\u6b65\u7684\u6570\u636e\u5904\u7406\uff0c\u5982\u6570\u636e\u8f6c\u6362\u3001\u8fc7\u6ee4\u7b49\u3002*\/\n\\copy measurement_y2008m02 from 'measurement_y2008m02'\n\/* \u5728\u9002\u5f53\u7684\u65f6\u5019\uff0c\u6216\u8005\u8bf4\u5728\u9700\u8981\u7684\u65f6\u5019\uff0c\u8ba9\u8be5\u8868\u7ee7\u627f\u4e3b\u8868\u3002*\/\nALTER TABLE measurement_y2008m02 INHERIT measurement;\n7). \u786e\u4fddpostgresql.conf\u91cc\u7684\u914d\u7f6e\u53c2\u6570constraint_exclusion\u662f\u6253\u5f00\u7684\u3002\u6ca1\u6709\u8fd9\u4e2a\u53c2\u6570\uff0c\u67e5\u8be2\u4e0d\u4f1a\u6309\u7167\u9700\u8981\u8fdb\u884c\u4f18\u5316\u3002\u8fd9\u91cc\u6211\u4eec\u9700\u8981\u505a\u7684\u662f\u786e\u4fdd\u8be5\u9009\u9879\u5728\u914d\u7f6e\u6587\u4ef6\u4e2d\u6ca1\u6709\u88ab\u6ce8\u91ca\u6389\u3002\n\/> pwd\n\/opt\/PostgreSQL\/9.1\/data\n\/> cat postgresql.conf | grep \"constraint_exclusion\"\nconstraint_exclusion = partition # on, off, or partition\n\n3. \u5206\u533a\u548c\u7ea6\u675f\u6392\u9664\uff1a\n\u7ea6\u675f\u6392\u9664(Constraint exclusion)\u662f\u4e00\u79cd\u67e5\u8be2\u4f18\u5316\u6280\u5de7\uff0c\u5b83\u6539\u8fdb\u4e86\u7528\u4e0a\u9762\u65b9\u6cd5\u5b9a\u4e49\u7684\u8868\u5206\u533a\u7684\u6027\u80fd\u3002\u6bd4\u5982\uff1a\nSET constraint_exclusion = on;\nSELECT count(*) FROM measurement WHERE logdate >= DATE '2006-01-01';\n\u5982\u679c\u6ca1\u6709\u7ea6\u675f\u6392\u9664\uff0c\u4e0a\u9762\u7684\u67e5\u8be2\u4f1a\u626b\u63cfmeasurement\u8868\u4e2d\u7684\u6bcf\u4e00\u4e2a\u5206\u533a\u3002\u6253\u5f00\u4e86\u7ea6\u675f\u6392\u9664\u4e4b\u540e\uff0c\u89c4\u5212\u5668\u5c06\u68c0\u67e5\u6bcf\u4e2a\u5206\u533a\u7684\u7ea6\u675f\u7136\u540e\u518d\u89c6\u56fe\u8bc1\u660e\u8be5\u5206\u533a\u4e0d\u9700\u8981\u88ab\u626b\u63cf\uff0c\u56e0\u4e3a\u5b83\u4e0d\u80fd\u5305\u542b\u4efb\u4f55\u7b26\u5408WHERE\u5b50\u53e5\u6761\u4ef6\u7684\u6570\u636e\u884c\u3002\u5982\u679c\u89c4\u5212\u5668\u53ef\u4ee5\u8bc1\u660e\u8fd9\u4e2a\uff0c\u5b83\u5c31\u628a\u8be5\u5206\u533a\u4ece\u67e5\u8be2\u89c4\u5212\u91cc\u6392\u9664\u51fa\u53bb\u3002\n\u4f60\u53ef\u4ee5\u4f7f\u7528EXPLAIN\u547d\u4ee4\u663e\u793a\u4e00\u4e2a\u89c4\u5212\u5728constraint_exclusion\u6253\u5f00\u548c\u5173\u95ed\u60c5\u51b5\u4e0b\u7684\u4e0d\u540c\u3002\u7528\u4e0a\u9762\u65b9\u6cd5\u8bbe\u7f6e\u7684\u8868\u7684\u5178\u578b\u7684\u7f3a\u7701\u89c4\u5212\u662f\uff1a \nSET constraint_exclusion = off;\nEXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2006-01-01'; \n QUERY PLAN\n-----------------------------------------------------------------------------------------------\n Aggregate (cost=158.66..158.68 rows=1 width=0)\n -> Append (cost=0.00..151.88 rows=2715 width=0)\n -> Seq Scan on measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n -> Seq Scan on measurement_yy04mm02 measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n -> Seq Scan on measurement_yy04mm03 measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n...\n -> Seq Scan on measurement_yy05mm12 measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n -> Seq Scan on measurement_yy06mm01 measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n\n\u4ece\u4e0a\u9762\u7684\u67e5\u8be2\u8ba1\u5212\u4e2d\u53ef\u4ee5\u770b\u51fa\uff0cPostgreSQL\u626b\u63cf\u4e86\u6240\u6709\u5206\u533a\u3002\u4e0b\u9762\u6211\u4eec\u518d\u770b\u4e00\u4e0b\u6253\u5f00\u7ea6\u675f\u6392\u9664\u4e4b\u540e\u7684\u67e5\u8be2\u8ba1\u5212\uff1a\nSET constraint_exclusion = on;\nEXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2006-01-01'; \n QUERY PLAN\n-----------------------------------------------------------------------------------------------\n Aggregate (cost=63.47..63.48 rows=1 width=0)\n -> Append (cost=0.00..60.75 rows=1086 width=0)\n -> Seq Scan on measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n -> Seq Scan on measurement_yy06mm01 measurement (cost=0.00..30.38 rows=543 width=0)\n Filter: (logdate >= '2006-01-01'::date)\n\u8bf7\u6ce8\u610f\uff0c\u7ea6\u675f\u6392\u9664\u53ea\u7531CHECK\u7ea6\u675f\u9a71\u52a8\uff0c\u800c\u4e0d\u4f1a\u7531\u7d22\u5f15\u9a71\u52a8\u3002\n\u76ee\u524d\u7248\u672c\u7684PostgreSQL\u4e2d\u8be5\u914d\u7f6e\u7684\u7f3a\u7701\u503c\u662fpartition\uff0c\u8be5\u503c\u662f\u4ecb\u4e8eon\u548coff\u4e4b\u95f4\u7684\u4e00\u79cd\u884c\u4e3a\u65b9\u5f0f\uff0c\u5373\u89c4\u5212\u5668\u53ea\u4f1a\u5c06\u7ea6\u675f\u6392\u9664\u5e94\u7528\u4e8e\u57fa\u4e8e\u5206\u533a\u8868\u7684\u67e5\u8be2\uff0c\u800con\u8bbe\u7f6e\u5219\u4f1a\u4e3a\u6240\u6709\u67e5\u8be2\u90fd\u8fdb\u884c\u7ea6\u675f\u6392\u9664\uff0c\u90a3\u4e48\u5bf9\u4e8e\u666e\u901a\u6570\u636e\u8868\u800c\u8a00\uff0c\u4e5f\u5c06\u4e0d\u5f97\u4e0d\u627f\u62c5\u7531\u8be5\u673a\u5236\u800c\u4ea7\u751f\u7684\u989d\u5916\u5f00\u9500\u3002\n\n\u7ea6\u675f\u6392\u9664\u5728\u4f7f\u7528\u65f6\u6709\u4ee5\u4e0b\u51e0\u70b9\u6ce8\u610f\u4e8b\u9879\uff1a\n1). \u7ea6\u675f\u6392\u9664\u53ea\u662f\u5728\u67e5\u8be2\u7684WHERE\u5b50\u53e5\u5305\u542b\u7ea6\u675f\u7684\u65f6\u5019\u624d\u751f\u6548\u3002\u4e00\u4e2a\u53c2\u6570\u5316\u7684\u67e5\u8be2\u4e0d\u4f1a\u88ab\u4f18\u5316\uff0c\u56e0\u4e3a\u5728\u8fd0\u884c\u65f6\u89c4\u5212\u5668\u4e0d\u77e5\u9053\u8be5\u53c2\u6570\u4f1a\u9009\u62e9\u54ea\u4e2a\u5206\u533a\u3002\u56e0\u6b64\u50cfCURRENT_DATE\u8fd9\u6837\u7684\u51fd\u6570\u5fc5\u987b\u907f\u514d\u3002\u628a\u5206\u533a\u952e\u503c\u548c\u53e6\u5916\u4e00\u4e2a\u8868\u7684\u5b57\u6bb5\u8fde\u63a5\u8d77\u6765\u4e5f\u4e0d\u4f1a\u5f97\u5230\u4f18\u5316\u3002\n2). \u5728CHECK\u7ea6\u675f\u91cc\u9762\u8981\u907f\u514d\u8de8\u6570\u636e\u7c7b\u578b\u7684\u6bd4\u8f83\uff0c\u56e0\u4e3a\u76ee\u524d\u89c4\u5212\u5668\u4f1a\u65e0\u6cd5\u8bc1\u660e\u8fd9\u6837\u7684\u6761\u4ef6\u4e3a\u5047\u3002\u6bd4\u5982\uff0c\u4e0b\u9762\u7684\u7ea6\u675f\u4f1a\u5728x\u662f\u6574\u6570\u5b57\u6bb5\u7684\u65f6\u5019\u53ef\u7528\uff0c\u4f46\u662f\u5728x\u662f\u4e00\u4e2abigint\u7684\u65f6\u5019\u4e0d\u80fd\u7528\uff1a\nCHECK (x = 1)\n\u5bf9\u4e8ebigint\u5b57\u6bb5\uff0c\u6211\u4eec\u5fc5\u987b\u4f7f\u7528\u7c7b\u4f3c\u4e0b\u9762\u8fd9\u6837\u7684\u7ea6\u675f\uff1a\nCHECK (x = 1::bigint)\n\u8fd9\u4e2a\u95ee\u9898\u5e76\u4e0d\u4ec5\u4ec5\u5c40\u9650\u4e8ebigint\u6570\u636e\u7c7b\u578b\uff0c\u5b83\u53ef\u80fd\u4f1a\u53d1\u751f\u5728\u4efb\u4f55\u7ea6\u675f\u7684\u7f3a\u7701\u6570\u636e\u7c7b\u578b\u4e0e\u5176\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\u4e0d\u5339\u914d\u7684\u573a\u5408\u3002\u5728\u63d0\u4ea4\u7684\u67e5\u8be2\u91cc\u7684\u8de8\u6570\u636e\u7c7b\u578b\u7684\u6bd4\u8f83\u901a\u5e38\u662fOK\u7684\uff0c\u53ea\u662f\u4e0d\u80fd\u5728CHECK\u6761\u4ef6\u91cc\u3002\n3). \u5728\u4e3b\u8868\u4e0a\u7684UPDATE\u548cDELETE\u547d\u4ee4\u5e76\u4e0d\u6267\u884c\u7ea6\u675f\u6392\u9664\u3002\n4). \u5728\u89c4\u5212\u5668\u8fdb\u884c\u7ea6\u675f\u6392\u9664\u65f6\uff0c\u4e3b\u8868\u4e0a\u7684\u6240\u6709\u5206\u533a\u7684\u6240\u6709\u7ea6\u675f\u90fd\u5c06\u4f1a\u88ab\u68c0\u67e5\uff0c\u56e0\u6b64\uff0c\u5927\u91cf\u7684\u5206\u533a\u4f1a\u663e\u8457\u589e\u52a0\u67e5\u8be2\u89c4\u5212\u7684\u65f6\u95f4\u3002\n5). \u5728\u6267\u884cANALYZE\u8bed\u53e5\u65f6\uff0c\u8981\u4e3a\u6bcf\u4e00\u4e2a\u5206\u533a\u90fd\u6267\u884c\u8be5\u547d\u4ee4\uff0c\u800c\u4e0d\u662f\u4ec5\u4ec5\u5bf9\u4e3b\u8868\u6267\u884c\u8be5\u547d\u4ee4\u3002<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"\u4e00\u3001\u8868\u7684\u7ee7\u627f\uff1a \u8fd9\u4e2a\u6982\u5ff5\u5bf9\u4e8e\u5f88\u591a\u5df2\u7ecf\u719f\u6089\u5176\u4ed6\u6570\u636e\u5e93\u7f16\u7a0b\u7684\u5f00\u53d1\u4eba\u5458\u800c\u8a00\u4f1a\u591a\u5c11\u6709\u4e9b\u964c\u751f\uff0c\u7136\u800c\u5b83\u7684\u5b9e\u73b0\u65b9\u5f0f\u548c\u8bbe\u8ba1\u539f\u7406\u5374\u662f\u7b80\u5355\u6613\u61c2\uff0c\u73b0\u5728\u5c31\u8ba9\u6211\u4eec\u4ece\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\u5f00\u59cb\u5427\u3002 1. \u7b2c\u4e00\u4e2a\u7ee7\u627f\u8868\uff1a CREATE TABLE cities ( –\u7236\u8868 name text, population float, altitude int ); CREATE TABLE capitals ( –\u5b50\u8868 state char(2) ) INHERITS (cities); capitals\u8868\u7ee7\u627f\u81eacities\u8868\u7684\u6240\u6709\u5c5e\u6027\u3002\u5728PostgreSQL\u91cc\uff0c\u4e00\u4e2a\u8868\u53ef\u4ee5\u4ece\u96f6\u4e2a\u6216\u591a\u4e2a\u5176\u5b83\u8868\u4e2d\u7ee7\u627f\u5c5e\u6027\uff0c\u800c\u4e14\u4e00\u4e2a\u67e5\u8be2\u65e2\u53ef\u4ee5\u5f15\u7528\u7236\u8868\u4e2d\u7684\u6240\u6709\u884c\uff0c\u4e5f\u53ef\u4ee5\u5f15\u7528\u7236\u8868\u7684\u6240\u6709\u884c\u52a0\u4e0a\u5176\u6240\u6709\u5b50\u8868\u7684\u884c\uff0c\u5176\u4e2d\u540e\u8005\u662f\u7f3a\u7701\u884c\u4e3a\u3002 MyTest=# INSERT INTO cities values(‘Las Vegas’, 1.53, 2174); –\u63d2\u5165\u7236\u8868 INSERT 0 1 MyTest=# INSERT INTO cities values(‘Mariposa’,3.30,1953); –\u63d2\u5165\u7236\u8868 INSERT 0 1 MyTest=# INSERT INTO capitals values(‘Madison’,4.34,845,’WI’);–\u63d2\u5165\u5b50\u8868 INSERT 0 1 MyTest=# SELECT name, altitude FROM cities WHERE altitude > 500; –\u7236\u8868\u548c\u5b50\u8868\u7684\u6570\u636e\u5747\u88ab\u53d6\u51fa\u3002 name | altitude ———–+———- Las Vegas | 2174 Mariposa | 1953 Madison | 845 (3 rows) MyTest=# SELECT name, altitude FROM capitals WHERE altitude > 500; –\u53ea\u6709\u5b50\u8868\u7684\u6570\u636e\u88ab\u53d6\u51fa\u3002 name | altitude ———+———- Madison | 845 (1 row) \u5982\u679c\u5e0c\u671b\u53ea\u4ece\u7236\u8868\u4e2d\u63d0\u53d6\u6570\u636e\uff0c\u5219\u9700\u8981\u5728SQL\u4e2d\u52a0\u5165ONLY\u5173\u952e\u5b57\uff0c\u5982\uff1a MyTest=# SELECT name,altitude FROM ONLY cities WHERE altitude > 500; name | altitude ———–+———- Las Vegas | 2174 Mariposa | 1953 (2 rows) \u4e0a\u4f8b\u4e2dcities\u524d\u9762\u7684”ONLY”\u5173\u952e\u5b57\u8868\u793a\u8be5\u67e5\u8be2\u5e94\u8be5\u53ea\u5bf9cities\u8fdb\u884c\u67e5\u627e\u800c\u4e0d\u5305\u62ec\u7ee7\u627f\u7ea7\u522b\u4f4e\u4e8ecities\u7684\u8868\u3002\u8bb8\u591a\u6211\u4eec\u5df2\u7ecf\u8ba8\u8bba\u8fc7\u7684\u547d\u4ee4–SELECT\uff0cUPDATE\u548cDELETE–\u652f\u6301\u8fd9\u4e2a”ONLY”\u7b26\u53f7\u3002 \u5728\u6267\u884c\u6574\u8868\u6570\u636e\u5220\u9664\u65f6\uff0c\u5982\u679c\u76f4\u63a5truncate\u7236\u8868\uff0c\u6b64\u65f6\u7236\u8868\u548c\u5176\u6240\u6709\u5b50\u8868\u7684\u6570\u636e\u5747\u88ab\u5220\u9664\uff0c\u5982\u679c\u53ea\u662ftruncate\u5b50\u8868\uff0c\u90a3\u4e48\u5176\u7236\u8868\u7684\u6570\u636e\u5c06\u4e0d\u4f1a\u53d8\u5316\uff0c\u53ea\u662f\u5b50\u8868\u4e2d\u7684\u6570\u636e\u88ab\u6e05\u7a7a\u3002 MyTest=# TRUNCATE TABLE cities; –\u7236\u8868\u548c\u5b50\u8868\u7684\u6570\u636e\u5747\u88ab\u5220\u9664\u3002 TRUNCATE TABLE MyTest=# SELECT * FROM capitals; name | population | altitude | state ——+————+———-+——- (0 rows) 2. \u786e\u5b9a\u6570\u636e\u6765\u6e90\uff1a \u6709\u65f6\u5019\u4f60\u53ef\u80fd\u60f3\u77e5\u9053\u67d0\u6761\u8bb0\u5f55\u6765\u81ea\u54ea\u4e2a\u8868\u3002\u5728\u6bcf\u4e2a\u8868\u91cc\u6211\u4eec\u90fd\u6709\u4e00\u4e2a\u7cfb\u7edf\u9690\u542b\u5b57\u6bb5tableoid\uff0c\u5b83\u53ef\u4ee5\u544a\u8bc9\u4f60\u8868\u7684\u6765\u6e90\uff1a MyTest=# SELECT tableoid, name, altitude FROM cities WHERE altitude > 500; tableoid | name | altitude ———-+———–+———- 16532 | Las Vegas | 2174 16532 | Mariposa | 1953 16538 | Madison | 845 (3 rows) \u4ee5\u4e0a\u7684\u7ed3\u679c\u53ea\u662f\u7ed9\u51fa\u4e86tableoid\uff0c\u4ec5\u4ec5\u901a\u8fc7\u8be5\u503c\uff0c\u6211\u4eec\u8fd8\u662f\u65e0\u6cd5\u770b\u51fa\u5b9e\u9645\u7684\u8868\u540d\u3002\u8981\u5b8c\u6210\u6b64\u64cd\u4f5c\uff0c\u6211\u4eec\u5c31\u9700\u8981\u548c\u7cfb\u7edf\u8868pg_class\u8fdb\u884c\u5173\u8054\uff0c\u4ee5\u901a\u8fc7tableoid\u5b57\u6bb5\u4ece\u8be5\u8868\u4e2d\u63d0\u53d6\u5b9e\u9645\u7684\u8868\u540d\uff0c\u89c1\u4ee5\u4e0b\u67e5\u8be2\uff1a MyTest=# SELECT p.relname, c.name, c.altitude FROM cities c,pg_class p WHERE c.altitude > 500 and c.tableoid = p.oid; relname | name | altitude ———-+———–…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_eb_attr":"","footnotes":""},"categories":[89,80],"tags":[],"class_list":["post-1627","post","type-post","status-publish","format-standard","hentry","category-postgres-db","category-80"],"_links":{"self":[{"href":"https:\/\/oneai.eu.org\/index.php?rest_route=\/wp\/v2\/posts\/1627","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneai.eu.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/oneai.eu.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/oneai.eu.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/oneai.eu.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1627"}],"version-history":[{"count":1,"href":"https:\/\/oneai.eu.org\/index.php?rest_route=\/wp\/v2\/posts\/1627\/revisions"}],"predecessor-version":[{"id":1628,"href":"https:\/\/oneai.eu.org\/index.php?rest_route=\/wp\/v2\/posts\/1627\/revisions\/1628"}],"wp:attachment":[{"href":"https:\/\/oneai.eu.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1627"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/oneai.eu.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1627"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/oneai.eu.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1627"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}