{"id":160055,"date":"2024-11-03T19:54:20","date_gmt":"2024-11-03T11:54:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160055\/"},"modified":"2024-11-03T19:54:21","modified_gmt":"2024-11-03T11:54:21","slug":"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-acos","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160055\/","title":{"rendered":"OceanBase \u6559\u7a0b\uff1aOceanBase ACOS"},"content":{"rendered":"

OceanBase \u6559\u7a0b\uff1aOceanBase ACOS<\/h1>\n

\u5728\u7576\u4eca\u7684\u6578\u64da\u5eab\u6280\u8853\u4e2d\uff0cOceanBase \u4f5c\u70ba\u4e00\u500b\u9ad8\u6027\u80fd\u7684\u5206\u4f48\u5f0f\u6578\u64da\u5eab\u7cfb\u7d71\uff0c\u8d8a\u4f86\u8d8a\u53d7\u5230\u958b\u767c\u8005\u548c\u4f01\u696d\u7684\u9752\u775e\u3002\u5b83\u7531\u963f\u91cc\u5df4\u5df4\u96c6\u5718\u958b\u767c\uff0c\u65e8\u5728\u652f\u6301\u5927\u898f\u6a21\u7684\u5728\u7dda\u4ea4\u6613\u8655\u7406\uff08OLTP\uff09\u548c\u5728\u7dda\u5206\u6790\u8655\u7406\uff08OLAP\uff09\u3002\u672c\u6587\u5c07\u91cd\u9ede\u4ecb\u7d39 OceanBase \u7684 ACOS \u51fd\u6578\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u548c\u4f7f\u7528\u9019\u4e00\u529f\u80fd\u3002<\/p>\n

\u4ec0\u9ebc\u662f ACOS \u51fd\u6578\uff1f<\/h2>\n

ACOS \u51fd\u6578\u662f\u53cd\u9918\u5f26\u51fd\u6578\uff0c\u7528\u65bc\u8a08\u7b97\u4e00\u500b\u6578\u5b57\u7684\u53cd\u9918\u5f26\u503c\u3002\u9019\u500b\u51fd\u6578\u7684\u8f38\u5165\u7bc4\u570d\u662f -1 \u5230 1\uff0c\u8fd4\u56de\u503c\u7684\u7bc4\u570d\u662f 0 \u5230 \u03c0\uff08\u5f27\u5ea6\uff09\u3002\u5728 OceanBase \u4e2d\uff0cACOS \u51fd\u6578\u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n

ACOS(x)<\/code><\/pre>\n
\u5176\u4e2d\uff0cx \u662f\u4e00\u500b\u4ecb\u65bc -1 \u548c 1 \u4e4b\u9593\u7684\u6d6e\u9ede\u6578\u3002<\/p>\n
ACOS \u51fd\u6578\u7684\u61c9\u7528\u5834\u666f<\/h2>\n
ACOS \u51fd\u6578\u5728\u8a31\u591a\u6578\u64da\u5206\u6790\u548c\u8a08\u7b97\u4e2d\u90fd\u975e\u5e38\u6709\u7528\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u8a08\u7b97\u89d2\u5ea6\u6216\u9032\u884c\u4e09\u89d2\u51fd\u6578\u904b\u7b97\u7684\u5834\u5408\u3002\u4f8b\u5982\uff0c\u5728\u8a08\u7b97\u5169\u500b\u5411\u91cf\u4e4b\u9593\u7684\u593e\u89d2\u6642\uff0cACOS \u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u7372\u5f97\u6240\u9700\u7684\u89d2\u5ea6\u503c\u3002<\/p>\n
\u793a\u4f8b\uff1a\u8a08\u7b97\u5169\u500b\u5411\u91cf\u7684\u593e\u89d2<\/h3>\n
\u5047\u8a2d\u6211\u5011\u6709\u5169\u500b\u4e09\u7dad\u5411\u91cf A \u548c B\uff0c\u5206\u5225\u70ba A(x1, y1, z1) \u548c B(x2, y2, z2)\u3002\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u6b65\u9a5f\u4f86\u8a08\u7b97\u5b83\u5011\u4e4b\u9593\u7684\u593e\u89d2\uff1a<\/p>\n
    \n
  1. \u8a08\u7b97\u5169\u500b\u5411\u91cf\u7684\u9ede\u7a4d\uff1adot_product = x1 * x2 + y1 * y2 + z1 * z2<\/code><\/li>\n
  2. \u8a08\u7b97\u5169\u500b\u5411\u91cf\u7684\u6a21\u9577\uff1amagnitude_A = SQRT(x1 * x1 + y1 * y1 + z1 * z1)<\/code><\/li>\n
  3. magnitude_B = SQRT(x2 * x2 + y2 * y2 + z2 * z2)<\/code><\/li>\n
  4. \u4f7f\u7528 ACOS \u51fd\u6578\u8a08\u7b97\u593e\u89d2\uff1aangle = ACOS(dot_product \/ (magnitude_A * magnitude_B))<\/code><\/li>\n<\/ol>\n
    \u4ee5\u4e0b\u662f\u4f7f\u7528 OceanBase SQL \u8a9e\u6cd5\u7684\u793a\u4f8b\uff1a<\/p>\n
    \nSELECT \n    ACOS(\n        (x1 * x2 + y1 * y2 + z1 * z2) \/ \n        (SQRT(x1 * x1 + y1 * y1 + z1 * z1) * SQRT(x2 * x2 + y2 * y2 + z2 * z2))\n    ) AS angle\nFROM \n    vectors_table;\n<\/code><\/pre>\n
    \u6ce8\u610f\u4e8b\u9805<\/h2>\n
    \u5728\u4f7f\u7528 ACOS \u51fd\u6578\u6642\uff0c\u5fc5\u9808\u78ba\u4fdd\u8f38\u5165\u503c\u5728 -1 \u5230 1 \u7684\u7bc4\u570d\u5167\u3002\u5982\u679c\u8f38\u5165\u503c\u8d85\u51fa\u6b64\u7bc4\u570d\uff0c\u5c07\u6703\u5c0e\u81f4\u932f\u8aa4\u3002\u56e0\u6b64\uff0c\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u5efa\u8b70\u5728\u8abf\u7528 ACOS \u51fd\u6578\u4e4b\u524d\u9032\u884c\u7bc4\u570d\u6aa2\u67e5\u3002<\/p>\n
    \u7bc4\u570d\u6aa2\u67e5\u793a\u4f8b<\/h3>\n
    \nSELECT \n    CASE \n        WHEN x >= -1 AND x <= 1 THEN ACOS(x) \n        ELSE NULL \n    END AS acos_value\nFROM \n    values_table;\n<\/code><\/pre>\n
    \u7e3d\u7d50<\/h2>\n
    OceanBase \u7684 ACOS \u51fd\u6578\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u5728\u6578\u64da\u5206\u6790\u548c\u8a08\u7b97\u4e2d\u89e3\u6c7a\u8a31\u591a\u554f\u984c\u3002\u901a\u904e\u672c\u6587\u7684\u4ecb\u7d39\u548c\u793a\u4f8b\uff0c\u76f8\u4fe1\u8b80\u8005\u80fd\u5920\u66f4\u597d\u5730\u7406\u89e3\u5982\u4f55\u5728 OceanBase \u4e2d\u4f7f\u7528 ACOS \u51fd\u6578\u9032\u884c\u8a08\u7b97\u3002\u5982\u679c\u60a8\u5c0d\u65bc \u9999\u6e2f VPS<\/a> \u670d\u52d9\u6216\u5176\u4ed6\u76f8\u95dc\u6280\u8853\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u8cc7\u8a0a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
    \u5b66\u4e60\u5982\u4f55\u4f7f\u7528 OceanBase ACOS \u51fd\u6570\uff0c\u638c\u63e1\u5176\u8bed\u6cd5\u548c\u5e94\u7528\uff0c\u63d0\u5347\u6570\u636e\u5e93\u67e5\u8be2\u6548\u7387\uff0c\u4f18\u5316\u6570\u636e\u5206\u6790\u80fd\u529b\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-160055","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160055","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"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=160055"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160055\/revisions"}],"predecessor-version":[{"id":160056,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160055\/revisions\/160056"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160055"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160055"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160055"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}