{"id":225047,"date":"2015-10-09T00:33:54","date_gmt":"2015-10-08T16:33:54","guid":{"rendered":"http:\/\/yangzhe1991.org\/blog\/?p=225047"},"modified":"2015-10-09T00:58:46","modified_gmt":"2015-10-08T16:58:46","slug":"datamodel-and-cql-cassandra-does-not-have-sql","status":"publish","type":"post","link":"https:\/\/yangzhe1991.org\/blog\/2015\/10\/datamodel-and-cql-cassandra-does-not-have-sql\/","title":{"rendered":"Cassandra\u7684\u6570\u636e\u6a21\u578b\u548cCQL\u2014\u2014Cassandra does not have SQL"},"content":{"rendered":"<p><a href=\"https:\/\/yangzhe1991.org\/blog\/2015\/09\/cassandra-introduction\/\">Cassandra\u7cfb\u5217\u6587\u7ae0<\/a>\u7684\u7b2c\u4e8c\u7bc7\u3002<\/p>\n<p><!--more--><\/p>\n<p>\u5728\u8bf4CQL\u4e4b\u524d\uff0c\u5f97\u5148\u8bf4\u4e00\u4e0bBigTable\u3002\u8bf4BigTable\u524d\uff0c\u5f97\u8bf4\u4e0bNoSQL\u3002\u5728\u8bf4NoSQL\u4e4b\u524d\uff0c\u5f97\u8bf4\u4e0b\u5173\u7cfb\u578b\u6570\u636e\u5e93\u3002<\/p>\n<p>\u5173\u7cfb\u578b\u6570\u636e\u5e93\u662f\u4ec0\u4e48\uff0c\u5176\u5b9e\u6211\u4e5f\u8bf4\u4e0d\u597d\uff0c\u751a\u81f3\u641c\u4e86\u4e00\u5708\u5b9a\u4e49\u4e5f\u6ca1\u6709\u641c\u5230\u4e00\u4e2a\u6070\u5f53\u7684\u4e2d\u6587\u5b9a\u4e49\uff0c\u597d\u5728\u641c\u5230\u4e86\u4e2a<a href=\"http:\/\/db-engines.com\/en\/article\/Relational+DBMS?ref=RDBMS\">\u82f1\u6587\u7684\u5b9a\u4e49<\/a>\u89c9\u5f97\u6bd4\u8f83\u6070\u5f53\uff1a<\/p>\n<p>Relational database management systems (RDBMS) support the relational (=table-oriented) data model. The schema of a table (=relation schema) is defined by the table name and a fixed number of attributes with fixed data types. A record (=entity) corresponds to a row in the table and consists of the values of each attribute. A relation thus consists of a set of uniform records.<\/p>\n<p>\u4e5f\u5c31\u662f\u8bf4\uff0c\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7684\u6570\u636e\u6a21\u578b\u662f\u57fa\u4e8e\u201c\u8868\u201d\u7684\u3002\u8868\u4f5c\u4e3a\u4e00\u79cd\u4e8c\u7ef4\u7ed3\u6784\uff0c\u6bcf\u884c\u662f\u4e00\u6761\u8bb0\u5f55\uff0c\u5e76\u4e14\u6bcf\u6761\u8bb0\u5f55\u90fd\u4e92\u4e0d\u76f8\u540c\uff1b\u8868\u7684\u6bcf\u5217\u662f\u8fd9\u6761\u8bb0\u5f55\u7684\u4e00\u4e2a\u5c5e\u6027\u3002\u6b64\u5916\uff0c\u5173\u7cfb\u578b\u6570\u636e\u5e93\u8fd8\u5e94\u8be5\u652f\u6301\u591a\u79cd\u64cd\u4f5c\uff0c\u9664\u4e86\u57fa\u672c\u7684CRUD\uff0c\u8fd8\u5e94\u8be5\u652f\u6301\u96c6\u5408\u64cd\u4f5c\uff08\u53d6\u5e76\u3001\u4ea4\u3001\u5dee\uff09\u4ee5\u53caJoin\u2014\u2014\u4e00\u79cd\u5c06\u591a\u4e2a\u8868\u7ec4\u5408\u8fde\u63a5\u7684\u67e5\u8be2\u64cd\u4f5c\u3002\u9488\u5bf9\u5173\u7cfb\u6570\u636e\u5e93\u7684\u6a21\u578b\uff0c\u6709\u4e00\u5957\u7279\u6b8a\u7684\u8bed\u8a00\u6765\u5bf9\u6570\u636e\u5e93\u8fdb\u884c\u64cd\u4f5c\uff0c\u4e5f\u5c31\u662fStructured Query Language\uff0cSQL\u3002<\/p>\n<p>\u4f3c\u4e4e\u53ea\u8981\u4e0d\u662f\u5173\u7cfb\u578b\u6570\u636e\u5e93\uff0c\u90fd\u53ef\u4ee5\u79f0\u4e4b\u4e3aNoSQL\u3002NoSQL\u7684\u51fa\u73b0\u9053\u7406\u5f88\u7b80\u5355\uff0c\u5c31\u662f\u5173\u7cfb\u578b\u6570\u636e\u5e93\u592a\u590d\u6742\uff0c\u800c\u5f88\u591a\u6570\u636e\u5b58\u50a8\u573a\u666f\u4e2d\u5bf9\u5173\u7cfb\u6a21\u578b\u7684\u9700\u6c42\u6ca1\u90a3\u4e48\u5927\uff0c\u7b80\u5316\u4e86\u6a21\u578b\u4e4b\u540e\u4e0d\u4ec5\u5b9e\u73b0\u7b80\u5355\u800c\u4e14\u6027\u80fd\u4e5f\u80fd\u597d\u4e00\u4e9b\u3002\u8fd8\u662f\u90a3\u53e5\u8bdd\uff0c\u4e0d\u8c08\u9700\u6c42\u573a\u666f\u53ea\u8c08\u5229\u5f0a\u662f\u800d\u6d41\u6c13\uff0c\u6240\u4ee5\u8fd9\u4e24\u8005\u5e94\u8be5\u662f\u4e92\u4e3a\u8865\u5145\u7684\u5173\u7cfb\uff0c\u4e0d\u662f\u66ff\u4ee3\u5173\u7cfb\u3002\u9664\u975e\u5230\u4e86\u67d0\u5929\uff0c\u6027\u80fd\u5b8c\u5168\u4e0d\u518d\u662f\u74f6\u9888\uff08\u867d\u7136\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u7406\u8bba\u4e0a\u53ef\u4ee5\u52a0\u673a\u5668\u63d0\u9ad8\u6027\u80fd\uff0c\u4f46\u662f\u8fd8\u6709\u4e2a\u6210\u672c\u95ee\u9898\uff0c\u6240\u4ee5\u672c\u8d28\u4e0a\u8fd8\u662f\u6027\u80fd\u95ee\u9898\uff09\uff0c\u90a3\u4e48NoSQL\u7684\u7b80\u5316\u53ea\u5269\u4e0b\u4e86\u4f7f\u7528\u4e0a\uff0c\u800c\u4f7f\u7528\u4e0a\u53ef\u4ee5\u9760ORM\u628aSQL\u53d8\u6210NoSQL\uff0c\u90a3\u4e2a\u65f6\u5019\u5012\u662f\u5173\u7cfb\u578b\u6570\u636e\u5e93\u53ef\u4ee5\u4e00\u7edf\u5929\u4e0b\u2026\u2026<\/p>\n<p>\u56e0\u4e3a\u201c\u4e0d\u7b26\u5408RDBMS\u6a21\u578b\u7684\u6570\u636e\u5e93\u90fd\u662fNoSQL\u201d\uff0c\u56e0\u800cNoSQL\u7684\u6570\u636e\u6a21\u578b\u4e5f\u4e0d\u5c3d\u76f8\u540c\u3002\u6700\u7b80\u5355\u7684NoSQL\u6a21\u578b\u5c31\u662fK-V\u6a21\u578b\uff0c\u4e00\u4e2akey\u5bf9\u5e94\u4e00\u4e2avalue\u3002\u6216\u8005\u8bf4\u6574\u4e2a\u6570\u636e\u5e93\u5c31\u662f\u4e00\u4e2aMap\uff0cHashMap\u8fd8\u662fSortedMap\u4e0d\u4e00\u5b9a\u3002\u50cfMemcache\u5c31\u662f\u5178\u578b\u7684kv\u6570\u636e\u5e93\u3002\u4e00\u4e9b\u6570\u636e\u5e93\u80fd\u7a0d\u5fae\u9ad8\u7ea7\u70b9\uff0cvalue\u4e0d\u4e00\u5b9a\u53ea\u662f\u4e00\u4e2a\u5355\u7eaf\u7684string\u6216bytes\uff0c\u8fd8\u53ef\u4ee5\u5728\u6570\u636e\u5e93\u5c42\u9762\u652f\u6301\u591a\u79cd\u6570\u636e\u7c7b\u578b\uff0c\u751a\u81f3\u662f\u96c6\u5408\u7c7b\u578b\u3002Redis\u5c31\u56e0\u4e3a\u5176\u652f\u6301\u591a\u79cd\u7c7b\u578b\u7684value\u6240\u4ee5\u5c5e\u4e8e\u5728kv\u6570\u636e\u5e93\u4e2d\u6bd4\u8f83\u5f3a\u5927\u800c\u65b9\u4fbf\u7684\u3002<\/p>\n<p>\u6bd4kv\u6570\u636e\u5e93\u7a0d\u5fae\u5f3a\u5927\u4e00\u70b9\u7684\u6a21\u578b\u4e3b\u8981\u6709\u4e24\u79cd\uff0c\u4e00\u79cd\u662fMongoDB\u4e3a\u4ee3\u8868\u7684\u201c\u6587\u6863\u6570\u636e\u5e93\u201d\uff0c\u8fd9\u79cd\u6570\u636e\u5e93\u6700\u5927\u7684\u7279\u70b9\u662f\u201cschema-free\u201d\uff0c\u6bcf\u884c\u6570\u636e\u53ef\u4ee5\u6709\u591a\u4e2a\u5b57\u6bb5\u7684\u540c\u65f6\u53c8\u4e0d\u9700\u8981\u63d0\u524d\u5b9a\u4e49\u597d\u5b57\u6bb5\u7684schema\uff08\u4e5f\u5c31\u662f\u4e0d\u9700\u8981\u63d0\u524dcreate table\uff09\uff0c\u5e76\u4e14\u6bcf\u884c\u6570\u636e\u7684\u5b57\u6bb5\u540d\u53ef\u4ee5\u4e0d\u5c3d\u76f8\u540c\u3001\u968f\u610f\u8bbe\u7f6e\uff0c\u751a\u81f3\u652f\u6301\u5d4c\u5957\u3002\u8bf4\u767d\u4e86\uff0c\u4f60\u53ef\u4ee5\u7406\u89e3\u4e3a\u6bcf\u6761\u6570\u636e\u662f\u4e00\u4e2a\u7c7b\u4f3cjson\u7684\u7ed3\u6784\uff0c\u8fd9\u79cd\u6570\u636e\u5e93\u76f8\u5f53\u4e8e\u6709\u5904\u7406json\u7684\u80fd\u529b\uff0c\u5982\u6309\u67d0\u4e2a\u5b57\u6bb5\u5efa\u7d22\u5f15\u7b49\u529f\u80fd\u3002\u5982\u679c\u4e0d\u7528\u8fd9\u4e9b\u529f\u80fd\uff0c\u672c\u8d28\u4e0a\u76f8\u5f53\u4e8e\u628ajson\u5e8f\u5217\u5316\u7136\u540e\u653e\u5728kv\u6570\u636e\u5e93\u7684value\u4e2d\u3002\u800c\u56e0\u4e3a\u8fd9\u79cd\u6570\u636e\u5e93\u6ca1\u6709\u5b9a\u4e49schema\uff0c\u540c\u65f6\u4e5f\u7f3a\u5c11\u4e86\u4e00\u4e9bSQL\u64cd\u4f5c\uff0c\u6240\u4ee5\u4e0d\u5c5e\u4e8e\u5173\u7cfb\u578b\u6570\u636e\u5e93\u3002<\/p>\n<p>\u7b2c\u4e8c\u79cd\u662fBigTable\u91c7\u7528\u7684\u201cWide Column\u201d\u3002\u8fd9\u79cd\u6a21\u578b\u5728\u6bcf\u884c\u6570\u636e\u5185\u5d4c\u5957\u4e86\u4e00\u5c42kv\u7684map\uff0c\u76f8\u5f53\u4e8e\u6574\u4e2a\u6570\u636e\u6a21\u578b\u662f\u4e8c\u7ef4map\u3002\u867d\u7136RDBMS\u7684\u8868\u4e5f\u662f\u4e8c\u7ef4\u7684\uff0c\u4f46\u662f\u4efb\u4f55\u884c\u4e2d\u7684\u6bcf\u5217\u90fd\u662f\u63d0\u524d\u5b9a\u4e49\u3001\u800c\u540e\u4e00\u76f4\u56fa\u5b9a\u4e14\u76f8\u540c\u7684\uff0c\u76f8\u5f53\u4e8e\u4e0d\u65ad\u7684\u589e\u5220\u6570\u636e\u589e\u52a0\u4e86\u4e8c\u7ef4\u8868\u7684\u884c\u6570\u800c\u5217\u6570\u662f\u6c38\u8fdc\u4e0d\u53d8\u7684\u3002\u800cWide Column\u7684\u884c\u6570\u548c\u5217\u6570\u90fd\u662f\u4f1a\u968f\u7740\u6570\u636e\u7684\u589e\u5220\u800c\u53d8\u5316\u7684\uff0c\u5e76\u4e14\u5217\u540d\uff08\u4e5f\u5c31\u662f\u7b2c\u4e8c\u7ef4map\u7684key\uff09\u662f\u4e0d\u56fa\u5b9a\u7684\uff0c\u56e0\u800c\u4e5f\u7b97\u201cschema-free\u201d\u3002\u4f46MongoDB\u652f\u6301\u5d4c\u5957\uff0c\u53ea\u9650\u5236\u6700\u5916\u5c42\u4e00\u6761\u8bb0\u5f55\u7684\u5927\u5c0f\uff0c\u800cWide Column\u786e\u5b9a\u4e86row key\u548ccolumn key\u4e4b\u540e\u5c31\u786e\u5b9a\u4e86value\uff0cvalue\u53ea\u80fd\u662f\u57fa\u672c\u7c7b\u578b\u4e0d\u80fd\u65e0\u9650\u5d4c\u5957\uff08\u6709\u9650\u7684\u5d4c\u5957\uff0c\u6216\u8005\u8bf4value\u662f\u4e2a\u96c6\u5408\u7c7b\u578b\u8fd8\u662f\u53ef\u4ee5\u7684\uff09\uff0c\u8fd9\u5e94\u8be5\u4e5f\u7b97\u662f\u4e24\u8005\u7684\u6700\u5927\u533a\u522b\uff0c\u800c\u4e14\u4e24\u8005\u7684\u5b9e\u73b0\u539f\u7406\u5e94\u8be5\u662f\u5b8c\u5168\u4e0d\u540c\u7684\uff08\u5176\u5b9e\u6211\u4e0d\u77e5\u9053MongoDB\u662f\u600e\u4e48\u5b9e\u73b0\u7684\u2026\u2026\uff09\u3002\u867d\u7136BigTable\u8fd8\u652f\u6301\u7b2c\u4e09\u7ef4map\uff0c\u5176key\u4e3a\u65f6\u95f4\u6233\uff0c\u4f46\u672c\u8d28\u4e0a\u66f4\u591a\u7ef4\u662f\u6ca1\u6709\u533a\u522b\u7684\uff0c\u56e0\u4e3a\u8fd9\u53ea\u662f\u76f8\u5f53\u4e8emap\u7684key\u6709\u591a\u4e2a\u3001\u6392\u5e8f\u65f6\u6309\u987a\u5e8f\u9010\u4e2a\u6bd4\u8f83\u800c\u5df2\uff08\u53ea\u662f\u65f6\u95f4\u6233\u4f5c\u4e3a\u7279\u6b8a\u7684\u4e00\u7ef4\uff0c\u6570\u636e\u5e93\u4f1a\u81ea\u52a8\u53ea\u4fdd\u7559\u6700\u65b0\u7684\u82e5\u5e72\u4e2a\u7248\u672c\uff0c\u5269\u4e0b\u7684\u81ea\u52a8\u5220\u6389\uff09\u3002\u5b9e\u9645\u4e0a\u5728HBase\u7684\u5b9e\u73b0\u4e2d\uff0c\u662f\u628a\u6240\u6709\u7ef4\u538b\u6241\u53d8\u6210\u4e00\u4e2a\u5927\u7684SortedMap\u7684\uff08\u5185\u5b58\u91cc\u4e3a\u8df3\u8868\uff09\u6765\u5b58\u50a8\u7684\uff0crow key\u3001column qualifier\uff08column key\uff09\u3001timestamp\u5171\u540c\u4f5c\u4e3akey\u5e76\u4e14\u6309\u987a\u5e8f\u6bd4\u8f83\u3002\u552f\u4e00\u7684\u533a\u522b\u662frow key\u4f5c\u4e3a\u4e00\u884c\u6570\u636e\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u800crow\u4f5c\u4e3a\u6700\u5c0f\u7684\u5b58\u50a8\u5355\u4f4d\uff0c\u4e00\u4e2arow\u65e0\u8bba\u6709\u591a\u5c11\u4e2acolumn\uff0c\u4e00\u5b9a\u90fd\u5c5e\u4e8e\u4e00\u4e2aregion\u8fdb\u800c\u5c5e\u4e8e\u4e00\u4e2a\u8282\u70b9\uff0c\u4e0d\u4f1a\u51fa\u73b0\u4e00\u4e2arow key\u7684\u524d\u82e5\u5e72\u4e2acolumn qualifier\u548c\u540e\u82e5\u5e72\u4e2a\u88ab\u5206\u5f00\u7684\u60c5\u51b5\u3002\u56e0\u800c\u65e0\u8bbaWide Column\u6a21\u578b\u4e2d\u6709\u591a\u5c11\u4e2akey\uff0c\u6700\u7ec8row key\u662f\u4e00\u7ef4\u3001\u5176\u4ed6key\u5171\u540c\u662f\u4e00\u7ef4\uff0c\u5f62\u6210\u4e00\u4e2a\u4e8c\u7ef4\u7684\u5173\u7cfb\u3002\u6b64\u5916\uff0c\u5176\u5b9e\u5f88\u5bb9\u6613\u7406\u89e3\uff0cWide Column\u53ea\u4f1a\u5728\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u4e2d\u51fa\u73b0\uff0c\u56e0\u4e3a\u5355\u673a\u6570\u636e\u5e93\u7684\u5168\u90e8\u6570\u636e\u90fd\u662f\u8fde\u7eed\u5b58\u50a8\uff0c\u591a\u7ef4map\u7684\u6bcf\u4e00\u7ef4\u662f\u6ca1\u4efb\u4f55\u533a\u522b\u7684\uff0c\u76f8\u5f53\u4e8eK-V\u6a21\u578b\u628aKey\u641e\u590d\u6742\u800c\u5df2\u3002<\/p>\n<p>\u8bb2\u5b8c\u4e86BigTable\uff0c\u7ec8\u4e8e\u53ef\u4ee5\u5c06\u4e3b\u89d2Cassandra\u4e86\u3002Cassandra\u867d\u7136\u5728\u5206\u5e03\u5f0f\u6a21\u578b\u4e0a\u7ee7\u627f\u4e86Dynamo\uff0c\u4f46Dynamo\u662fkv\u6a21\u578b\uff0cCassandra\u5e76\u6ca1\u6709\u76f4\u63a5\u4f7f\u7528\u7b80\u5355\u7684kv\u6a21\u578b\u800c\u662f\u4eceBigTable\u4e2d\u5b66\u4e86Wide Column\u3002\u5176\u5b9e\u539f\u56e0\u5f88\u7b80\u5355\uff0c\u90a3\u5c31\u662fkv\u6a21\u578b\u8fc7\u4e8e\u7b80\u5355\u4e86\u3002\u5927\u591a\u6570\u5e38\u89c1\u7684\u573a\u666f\u5f88\u96be\u505a\u5230\u4e00\u4e2a\u5b9e\u4f53\u53ea\u6709\u4e00\u4e2a\u5b57\u6bb5\uff0c\u56e0\u800ckv\u6570\u636e\u5e93\u53ea\u80fd\u8981\u4e48\u628a\u8fd9\u4e2a\u5b9e\u4f53\u7684\u591a\u4e2a\u5b57\u6bb5\u5171\u540c\u5b58\u50a8\u5728\u4e00\u4e2avalue\u5185\uff0c\u8981\u4e48\u628a\u8fd9\u4e2a\u5b9e\u4f53\u7684id\u52a0\u4e0a\u5b57\u6bb5\u540d\u7ec4\u6210\u4e00\u4e2akey\u4ece\u800c\u628a\u4e00\u4e2a\u5b9e\u4f53\u62c6\u6210\u591a\u884c\u3002\u524d\u8005\u5bfc\u81f4\u5982\u679c\u53ea\u60f3\u67e5\u627e\u4e00\u4e2a\u5b9e\u4f53\u7684\u5176\u4e2d\u4e00\u4e2a\u5b57\u6bb5\u4e5f\u4e0d\u5f97\u4e0d\u5168\u90e8\u8bfb\u51fa\u6765\u3001\u53cd\u5e8f\u5217\u5316\uff0c\u5982\u679c\u53ea\u4fee\u6539\u4e00\u4e2a\u5b57\u6bb5\u4e5f\u4e0d\u5f97\u4e0d\u5168\u90e8\u8bfb\u51fa\u6765\u3001\u53cd\u5e8f\u5217\u5316\u3001\u4fee\u6539\u3001\u518d\u5e8f\u5217\u5316\u3001\u518d\u5199\u5165\uff0c\u751a\u81f3\u5982\u679c\u60f3\u5e76\u53d1\u4fee\u6539\u4e00\u4e2a\u5b9e\u4f53\u7684\u4e0d\u540c\u5b57\u6bb5\u4e5f\u4e0d\u5f97\u4e0d\u5bf9\u6574\u884c\u6570\u636e\u52a0\u9501\uff1b\u540e\u8005\u5bfc\u81f4\u5982\u679c\u60f3\u8bfb\u5199\u4e00\u4e2a\u5b9e\u4f53\u7684\u591a\u4e2a\u5b57\u6bb5\u5c31\u5f97\u8bfb\u5199\u591a\u6b21\uff08\u5982\u679ckey\u662f\u6709\u5e8f\u7684\u8fd8\u597d\u70b9\uff0c\u53ef\u4ee5\u626b\uff0c\u6027\u80fd\u6bd4\u8bfb\u591a\u6b21\u597d\uff0c\u4f46Dynamo\u548cCassandra\u56e0\u4e3a\u8d77\u539f\u7406\u5bfc\u81f4key\u5f88\u96be\u6709\u5e8f\uff0c\u539f\u56e0\u4e0b\u4e00\u7bc7\u6587\u7ae0\u4f1a\u8bb2\uff09\u3002\u603b\u4e4b\u5355\u7eaf\u7684kv\u90fd\u8fdc\u4e0d\u5982Wide Column\u7684\u591a\u7ef4\u5173\u7cfb\u597d\u7528\u3002<\/p>\n<p>Cassandra\u5728\u6700\u5f00\u59cb\u4f7f\u7528thrift\u4f5c\u4e3aclient\u7684\u4ea4\u4e92\u63a5\u53e3\u3002\u6bcf\u4e2a\u96c6\u7fa4\u6709\u591a\u4e2akeyspace\uff0c\u6bcf\u4e2akeyspace\u6709\u591a\u4e2acolumn family\uff0c\u6bcf\u4e2acf\u7684\u6570\u636e\u72ec\u7acb\u5b58\u50a8\u3002CF\u4e0b\u9762\u662f\u4e00\u884c\u884c\u6570\u636e\uff0c\u6bcf\u884c\u6570\u636e\u6709\u4e00\u4e2akey\u548c\u82e5\u5e72\u4e2acolumn\uff0c\u6bcf\u4e2acolumn\u662f\u4e00\u4e2a\u7531 name, value, timestamp, ttl\u7ec4\u6210\u7684\u5143\u7ec4\u3002\u5176\u4e2dcolumn name\u4e5f\u5c31\u662fcolumn key\u3002\u867d\u7136Cassandra\u4e0d\u652f\u6301\u591a\u7248\u672c\uff0c\u540cname\u5199\u591a\u4e2a\u6570\u636e\u5c31\u4f1a\u662f\u65b0\u7684\u8986\u76d6\u65e7\u7684\uff0c\u4f46\u662f\u5982\u7cfb\u5217\u6587\u7ae0\u7684\u7b2c\u4e00\u7bc7\u6240\u8bb2\u7684\uff0cCassandra\u5224\u65ad\u65b0\u65e7\u7684\u552f\u4e00\u6807\u51c6\u5c31\u662f\u65f6\u95f4\u6233\uff0c\u56e0\u800c\u6bcf\u4e2a\u6570\u636e\u7684\u5199\u5165\u65f6\u95f4\u6233\u90fd\u8981\u6c38\u8fdc\u4fdd\u7559\u3002\u800cttl\u662f\u6570\u636e\u7684\u6709\u6548\u671f\uff0c\u5982\u679c\u8bbe\u7f6e\uff0c\u5230\u671f\u81ea\u52a8\u5220\u9664\uff08\u53ea\u662f\u8bfb\u4e0d\u5230\u800c\u5df2\uff0c\u7269\u7406\u4e0a\u4f9d\u7136\u4f1a\u4fdd\u7559\u4e00\u6bb5\u65f6\u95f4\uff0c\u4ee5\u540e\u4f1a\u8bf4\u4e3a\u5565\uff09\u3002\u5982\u679cCassandra\u53ea\u53d1\u5c55\u5230\u8fd9\u91cc\uff0c\u5b9e\u9645\u4e0a\u7528\u8d77\u6765\u8ddfHBase\u633a\u50cf\uff0c\u53ea\u662frow key\u975e\u6709\u5e8f\u3001\u4e0d\u652f\u6301\u591a\u7248\u672c\u800c\u5df2\u3002\u4e8e\u6b64\u540c\u65f6\uff0cthrift\u4e5f\u57fa\u672c\u4e0a\u66b4\u9732\u4e86\u5176\u5b58\u50a8\u5f15\u64ce\u7684\u5b58\u50a8\u65b9\u5f0f\u3002<\/p>\n<p>\u4e8e\u662f\u672c\u6587\u7684\u4e3b\u89d2\u7ec8\u4e8e\u51fa\u573a\u4e86\uff0cCassandra\u4ece1.2\u5f00\u59cb\u5f15\u5165CQL\u2014\u2014Cassandra Query Language\uff0c\u6765\u4f5c\u4e3a\u67e5\u8be2\u8bed\u8a00\uff0c\u662f\u76ee\u524d\u7248\u672c\u7684\u9996\u9009\u65b9\u5f0f\uff0c\u5e76\u4e14\u672a\u6765\u4f1a\u5f7b\u5e95\u5e9f\u9664thrift\u3002\u540c\u65f6\u56e0\u4e3aCQL\u662f\u4e13\u95e8\u4e3a\u4e86Cassandra\u5b9a\u4e49\u7684\u8bed\u8a00\uff0c\u65e0\u8bba\u901a\u4fe1\u534f\u8bae\u3001\u89e3\u6790\u590d\u6742\u5ea6\u4e0a\u90fd\u4f18\u4e8ethrift\uff0c\u56e0\u800cCQL\u7684\u6027\u80fd\u4f1a\u6bd4thrift\u597d\u4e0d\u5c11\u3002\u5e76\u4e14\u8bf8\u591a\u6700\u65b0\u529f\u80fd\u90fd\u53ea\u80fd\u5728CQL\u4e0a\u7528\uff0c\u56e0\u6b64\u65b0\u63a5\u89e6Cassandra\u7684\u8bdd\u53ea\u5173\u6ce8CQL\u5c31\u53ef\u4ee5\u4e86\u3002\u6b64\u5916\u968f\u7740CQL\u7684\u8fdb\u5316\uff0cCassandra\u7684\u6570\u636e\u5b58\u50a8\u683c\u5f0f\u4e5f\u5728\u53d8\u5316\uff0c\u6700\u5f00\u59cb\u7684CQL\u662f\u5b8c\u5168\u517c\u5bb9thrift\u7684\uff0c\u4f46\u4eceCQL3\u5f00\u59cb\u6570\u636e\u683c\u5f0f\u5df2\u7ecf\u4e0d\u517c\u5bb9thrift\u4e86\u3002<\/p>\n<p>\u9996\u5148\uff0cCQL\u5728\u6a21\u578b\u5b9a\u4e49\u4e0a\u53c2\u8003\u4e86\u5173\u7cfb\u578b\u6570\u636e\u5e93\uff0c\u4e5f\u4f7f\u7528\u4e8c\u7ef4\u8868\u683c\u5c06\u6570\u636eschema\u786e\u5b9a\u5316\uff0c\u4f46\u662f\u9664\u6b64\u4e4b\u5916\u6ca1\u6709\u4efb\u4f55\u76f8\u4f3c\u4e4b\u5904\u3002CQL\u5728\u5b9a\u4e49\u5217\u65f6\u4e5f\u9700\u8981\u6307\u5b9a\u4e3b\u952e\uff0c\u800c\u4e3b\u952e\u4e5f\u53ef\u4ee5\u6709\u591a\u4e2a\u3002\u5e76\u4e14\u4e3b\u952e\u5206\u4e3apartition key\u548cclustering column\u4e24\u79cd\uff0c\u524d\u8005\u5c31\u662frow key\uff0c\u800c\u540e\u8005\u5c31\u662fcolumn key\u3002\u4ee5\u524d\u7684thrift\u6a21\u578b\u4e2d\uff0crow key\u548ccolumn name\u662f\u4e00\u4e2a\u786e\u5b9a\u7684\u5b57\u6bb5\uff0c\u6ca1\u6709\u4e5f\u4e0d\u9700\u8981\u201c\u5b57\u6bb5\u540d\u201d\uff0c\u5c31\u50cfkv\u6570\u636e\u5e93\u7684\u4e24\u4e2a\u5217\u76f8\u5f53\u4e8e\u5c31\u53ebkey\u548cvalue\u4e0d\u80fd\u81ea\u5df1\u8d77\u540d\u5b57\u4e00\u6837\u3002\u800cCQL\u4e2d\u53ef\u4ee5\u7ed9row key\u548ccolumn key\u5206\u522b\u8d77\u540d\uff0c\u5e76\u4e14\u5206\u522b\u90fd\u53ef\u4ee5\u6709\u591a\u4e2a\uff0c\u751a\u81f3column key\u53ef\u4ee5\u6ca1\u6709\uff0c\u53d8\u6210\u4e00\u4e2a\u7eafkv\u6a21\u578b\u3002\u8fd9\u4e2a\u540d\u5b57\u5e76\u4e0d\u4f1a\u5b58\u50a8\u5728\u6bcf\u884c\u6570\u636e\u4e2d\uff0c\u76f4\u63a5\u5b58\u50a8\u5728meta\u4fe1\u606f\u4e2d\u5373\u53ef\u3002\u5982SQL\u4e00\u6837\uff0cprimary key\u65e0\u8bbapartition key\u8fd8\u662fclustering column\u90fd\u4e0d\u80fd\u4e3anull\uff0c\u800c\u975e\u4e3b\u952e\u5b57\u6bb5\u53ef\u4ee5\u6709\u591a\u4e2a\uff0c\u662f\u53ef\u4ee5\u4e3anull\u7684\u3002\u6362\u53e5\u8bdd\u8bf4\u5c31\u662fthrift\u6a21\u578b\u4e0b\u662f\u4e00\u4e2arow key+\u4e00\u4e2acolumn key\u5b9a\u4f4d\u4e00\u4e2avalue\uff1b\u800cCQL\u6a21\u578b\u4e0b\u662f\u4e00\u5230\u591a\u4e2arow key+\u96f6\u5230\u591a\u4e2acolumn key\u786e\u5b9a\u96f6\u5230\u591a\u4e2avalue\u3002<\/p>\n<p>CQL\u6a21\u578b\u4e2d\u7684\u884c\uff0c\u4e5f\u53eb\u4e00\u4e2aCQL row\uff0c\u5176\u5b9e\u672c\u8d28\u4e0a\u662fCassandra\u4e2dWide Column\u6a21\u578b\u7684\u4e00\u4e2a\u5217\uff0c\u53ea\u662f\u8fd9\u4e2a\u5217\u7684key\u53ef\u80fd\u4e0d\u53ea\u662f\u4e00\u4e2a\u65e0\u540d\u5b57\u6bb5\u800c\u53ef\u80fd\u662f\u591a\u4e2a\u5e26\u540d\u5b57\u7684\u5b57\u6bb5\uff0c\u800c\u4e14value\u53ef\u4ee5\u6709\u591a\u4e2a\u3002CQL\u652f\u6301\u591a\u4e2avalue\uff0c\u672c\u8d28\u4e0a\u662f\u6bcf\u5217\u6570\u636e\u5728\u5b58\u50a8\u591a\u4e2avalue\u65f6\u7528\u989d\u5916\u7684\u7a7a\u95f4\u628a\u6bcf\u4e2avalue\u5bf9\u5e94\u7684\u5b57\u6bb5\u540d\u4e5f\u5b58\u8fdb\u53bb\u4e86\uff0c\u56e0\u800cCQL table\u7684\u5b9a\u4e49\u4e2d\u53ef\u4ee5\u5b9a\u4e49\u5f88\u591a\u4e2aCQL column\uff0c\u5982\u679c\u67d0\u4e2aCQL row\u7684\u6570\u636e\u5f88\u7a00\u758f\uff0c\u5f88\u591aCQL column\u90fd\u662fnull\uff0c\u662f\u4e0d\u4f1a\u591a\u5360\u7528\u7a7a\u95f4\u7684\u3002CQL\u7684\u8bed\u6cd5\u4e5f\u652f\u6301\u521b\u5efa\u65e7\u683c\u5f0f\u517c\u5bb9thrift\u7684\u8868\uff0c\u52a0with compact storage\uff0c\u8fd9\u6837\u7684\u8868\u53ea\u652f\u6301\u4e00\u4e2a\u975e\u4e3b\u952e\u7684\u5217\uff0c\u5e76\u4e14\u4e0d\u80fd\u52a8\u6001\u589e\u51cf\u65b0\u5217\uff0c\u4e5f\u66f4\u7701\u7a7a\u95f4\u3002<\/p>\n<p>Cassandra\u867d\u7136\u56e0\u4e3a\u67b6\u6784\u539f\u56e0\u4e0d\u65b9\u4fbf\u8ba9row key\u6709\u5e8f\u5b58\u50a8\uff0c\u4f46\u662fclustering column\u662f\u6709\u5e8f\u7684\uff0c\u5e76\u4e14\u662f\u6309\u7167CQL\u5b9a\u4e49\u7684\u987a\u5e8f\u5206\u522b\u6bd4\u8f83\u5927\u5c0f\u6392\u5e8f\u3002\u6240\u4ee5\u5728\u67e5\u8be2\u7684\u65f6\u5019\u662f\u652f\u6301\u8303\u56f4\u67e5\u8be2\u8fde\u7eed\u7684\u6570\u636e\u7684\uff0c\u53ea\u80fd\u67e5\u8be2\u8fde\u7eed\u7684\u6570\u636e\u610f\u5473\u7740\u5fc5\u987b\u5728where\u8bed\u53e5\u4e2d\u9650\u5236\u5168\u90e8partition key\u7684\u76f8\u7b49\u5173\u7cfb\u3001\u524dx\u4e2aclustering column\u7684\u76f8\u7b49\u5173\u7cfb\u548c\u7b2cx+1\u4e2aclustering column\u7684\u5927\u5c0f\u6216\u76f8\u7b49\u5173\u7cfb\u3002\u5176\u4e2d0&lt;=x&lt;n\uff0cn\u4e3aclustering column\u7684\u4e2a\u6570\u3002\u4e3e\u4e2a\u4f8b\u5b50\u5c31\u662f\uff0c\u5047\u5982\u6709\u8fd9\u6837\u4e00\u4e2a\u8868\uff1a<\/p>\n<p>create table orders(<\/p>\n<p>userid string,<\/p>\n<p>date string,<\/p>\n<p>order_id int,<\/p>\n<p>comment string,<\/p>\n<p>primary key ((userid), date, order_id));<\/p>\n<p>\u4e0d\u641e\u8bed\u6cd5\u6559\u7a0b\u4e86\uff0c\u5148\u77e5\u9053\u8fd9\u4e2a\u8868\u4e2duserid\u662fpartition key\u3001date\u548corder_id\u662fclustering column\uff0ccomment\u662f\u666e\u901acolumn\u5c31\u884c\u3002insert\u548cupdate\u7684\u65f6\u5019\uff08cassandra\u5b8c\u5168\u4e0d\u533a\u5206\u8fd9\u4fe9\uff0c\u53ef\u4ee5insert\u5b58\u5728\u7684\u6570\u636e\u6216\u8005update\u4e0d\u5b58\u5728\u7684\uff09\u5fc5\u987b\u6307\u5b9a\u8fd9\u4e09\u4e2a\u5b57\u6bb5\uff0c\u8fd9\u4e09\u4e2a\u5b57\u6bb5\u5b8c\u5168\u4e00\u6837\u5c31\u4f1a\u88ab\u8ba4\u4f5c\u662f\u540c\u4e00\u4e2aCQL row\u8fdb\u800c\u4f1a\u8986\u76d6\u4e4b\u524d\u5199\u7684\u6570\u636e\u3002\u5728\u8bfb\u7684\u65f6\u5019\uff0c\u53ef\u4ee5select * from orders where userid=xx and date = yy and order_id=zz\uff0c\u8fd9\u6837\u53ea\u4f1a\u8fd4\u56de1 row\u6216\u80050 row\uff1b\u4e5f\u53ef\u4ee5select * from orders where userid=xx and date = yy and order_id&gt;zz\uff0c\u8fd9\u6837\u8fd4\u56de0\u5230\u591a\u884c\u6570\u636e\uff1b\u4e5f\u53ef\u4ee5select * from orders where userid=xx and date = yy\uff0c\u5b8c\u5168\u4e0d\u9650\u5236order_id\u8fd9\u6837\u5c31\u8fd4\u56de\u5168\u90e8(xx,yy)\u5bf9\u5e94\u4e0b\u7684\u6570\u636e\uff1b\u8fd8\u53ef\u4ee5select * from orders where userid=xx and (date, order_id) &gt; (yy, zz) \u6765\u67e5\u8be2\u4ece(xx,yy,zz)\u5f00\u59cb\u7684\u6570\u636e\u5e76\u4e14\u4e0d\u9650\u5236date\u4e00\u5b9a\u662fyy\u3002\u4f46\u662f\uff0c\u4f60\u4e0d\u80fdselect * from orders where userid=xx and order_id=zz\uff0c\u56e0\u4e3a\u4e0d\u9650\u5236date\u53ea\u9650\u5236order_id\u7684\u7ed3\u679c\u5fc5\u7136\u662f\u4e0d\u8fde\u7eed\u7684\uff0c\u800cCassandra\u53ea\u652f\u6301\u8fde\u7eed\u7684\u8303\u56f4\u67e5\u8be2\u3002<\/p>\n<p>\u80fd\u610f\u8bc6\u5230CQL\u7684\u8fd9\u4e2a\u9650\u5236\uff0c\u5e76\u4e14\u77e5\u9053\u8fd9\u4e2a\u9650\u5236\u7684\u5185\u5728\u539f\u7406\uff0c\u5c31\u57fa\u672c\u4e0a\u61c2Cassandra\u7684\u6570\u636e\u6a21\u578b\u4e86\u3002\u5728\u61c2\u8fd9\u4e2a\u4e4b\u524d\uff0c\u662f\u6ca1\u6709\u80fd\u529b\u751a\u81f3\u8bf4\u6ca1\u6709\u8d44\u683c\u7528Cassandra\u7684\u3002\u56e0\u6b64\u5b9e\u9645\u4e0a\u6211\u4e2a\u4eba\u89c9\u5f97Cassandra\u641e\u7684CQL\u867d\u7136\u6bd4\u8f83\u5f3a\u5927\u5e76\u4e14\u53ef\u4ee5\u628a\u6570\u636eschema\u5316\uff0c\u4f46\u5982\u679c\u4e0d\u4ed4\u7ec6\u770b\u6587\u6863\u662f\u5bb9\u6613\u5165\u5751\u7684\uff0c\u800c\u5f88\u591a\u7801\u519c\u8bf4\u5b9e\u8bdd\u6ca1\u6709\u4ed4\u7ec6\u770b\u6587\u6863\u7684\u610f\u8bc6\u548c\u80fd\u529b\u2026\u2026\u6240\u4ee5\u5982\u679c\u6709\u516c\u53f8\u7528Cassandra\uff0c\u5728\u65b0\u624b\u8bbe\u8ba1schema\u7684\u65f6\u5019\u4e00\u5b9a\u8981\u6709\u8001\u624b\u6765review\u9632\u6b62\u8fdb\u5751\u3002\u4e00\u4e9b\u9ad8\u7ea7\u529f\u80fd\u867d\u7136\u53ef\u4ee5\u7ed5\u8fc7\u8fd9\u4e2a\u9650\u5236\uff0c\u641e\u5f97\u201c\u975e\u5e38\u50cfSQL\u201d\uff0c\u6bd4\u5982secondary index\u3001materialized view\uff0c\u4f46\u90fd\u548c\u5173\u7cfb\u578b\u6570\u636e\u5e93\u5b9e\u73b0\u7c7b\u4f3c\u529f\u80fd\u6709\u672c\u8d28\u533a\u522b\uff0c\u5e76\u4e0d\u662f\u968f\u4fbf\u80fd\u4e71\u7528\u7684\uff0c\u53ef\u80fd\u56e0\u4f7f\u7528\u4e0d\u5f53\u9020\u6210\u6027\u80fd\u95ee\u9898\uff0c\u751a\u81f3\u4fee\u6539\u6570\u636e\u7684\u540c\u65f6\u4fee\u6539\u8fd9\u4e9b\u8f85\u52a9\u6570\u636e\u53ef\u80fd\u662f\u4e0d\u4fdd\u8bc1\u9694\u79bb\u6027\u7684\u56e0\u800c\u5bfc\u81f4\u8bfb\u5230\u810f\u6570\u636e\u3002<\/p>\n<p>Cassandra\u56e0\u4e3a\u5176NoSQL\u7684\u672c\u8d28\uff0c\u5bf9\u8de8\u884c\uff08CQL row\uff09\u67e5\u8be2\u7684\u652f\u6301\u6bd4\u8f83\u5f31\uff0c\u81f3\u4e8e\u8de8wide-column row\u7684\u80fd\u529b\u5c31\u66f4\u5f31\uff0c\u66f4\u522b\u8bf4\u8de8\u884c\u4e8b\u52a1\u4e86\uff0c\u56e0\u4e3a\u968f\u4fbf\u4e00\u4e2a\u8de8wide-column row\u7684\u67e5\u8be2\u90fd\u9700\u8981\u626b\u6574\u4e2a\u8868\uff08\u6682\u4e0d\u8003\u86513.0\u65b0\u589e\u7684materialized view\uff0c\u6bd5\u7adf3.0\u8fde\u6b63\u5f0f\u7248\u90fd\u8fd8\u6ca1\u53d1\uff09\uff0c\u626b\u6574\u4e2a\u8868\u5c31\u610f\u5473\u7740\u626b\u6574\u4e2a\u96c6\u7fa4\uff0c\u5f00\u9500\u975e\u5e38\u5927\u3002\u4e5f\u56e0\u6b64CQL\u662f\u4e0d\u592a\u9700\u8981\u4ec0\u4e48\u201c\u6162\u67e5\u8be2log\u201d\u7684\uff0c\u56e0\u4e3a\u5e94\u8be5\u8fde\u7528\u90fd\u4e0d\u7528\uff0c\u675c\u7edd\u4e00\u5207\u53ef\u80fd\u6162\u7684\u67e5\u8be2\u3002<\/p>\n<p>\u603b\u800c\u8a00\u4e4b\uff0c\u5982\u679c\u8bf4NoSQL\u662fNot only SQL\uff0c\u90a3CQL\u5c31\u662f\u2014\u2014Cassandra does not have SQL\u3002<\/p>\n<p>CQL\u5f53\u7136\u4e5f\u6709\u4ed6\u7684\u597d\u5904\uff0c\u6700\u5927\u7684\u597d\u5904\u5c31\u662f\u4e3aNoSQL\u5e26\u6765\u4e86schema\u3002\u7528\u5218\u5947\u7684\u8bdd\u8bf4\uff0c\u6570\u636e\u5e93\u7684schema\u6709\u70b9\u50cf\u7f16\u7a0b\u8bed\u8a00\u4e2d\u7684\u9759\u6001\u7c7b\u578b\uff0c\u7ea6\u675f\u66f4\u4e25\u683c\uff0c\u5c11\u4e86\u4e00\u4e9b\u81ea\u7531\uff0c\u9879\u76ee\u8d8a\u5927\u53ef\u80fd\u4f18\u52bf\u8d8a\u660e\u663e\u3002\u540c\u65f6CQL\u7ed5\u8fc7thrift\u7684\u675f\u7f1a\u4ece\u4e0b\u5230\u4e0a\u5b8c\u6574\u9020\u4e86\u8f6e\u5b50\u540e\uff0c\u66f4\u5bb9\u6613\u4f18\u5316\u6027\u80fd\uff0c\u8868\u8fbe\u80fd\u529b\u66f4\u5f3a\u4e5f\u65b9\u4fbf\u52a0\u65b0\u529f\u80fd\u3002\u540c\u65f6\u53ea\u8981\u914d\u5408\u5404\u79cdclient\u7684driver\uff0c\u5c31\u53ef\u4ee5\u7b80\u5316\u4ee3\u7801\u4e0d\u9700\u8981\u5199\u88f8\u7684CQL\u8bed\u53e5\uff0c\u7528\u8d77\u6765\u4e0d\u6bd4thrift\u9ebb\u70e6\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Cassandra\u7cfb\u5217\u6587\u7ae0\u7684\u7b2c\u4e8c\u7bc7\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[26],"_links":{"self":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts\/225047"}],"collection":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/comments?post=225047"}],"version-history":[{"count":5,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts\/225047\/revisions"}],"predecessor-version":[{"id":225054,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/posts\/225047\/revisions\/225054"}],"wp:attachment":[{"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/media?parent=225047"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/categories?post=225047"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yangzhe1991.org\/blog\/wp-json\/wp\/v2\/tags?post=225047"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}