{"id":423751,"date":"2021-04-03T10:02:57","date_gmt":"2021-04-03T02:02:57","guid":{"rendered":"http:\/\/4563.org\/?p=423751"},"modified":"2021-04-03T10:02:57","modified_gmt":"2021-04-03T02:02:57","slug":"%e5%85%b3%e4%ba%8e-n1-%e9%97%ae%e9%a2%98%e8%a7%a3%e5%86%b3%e6%96%b9%e6%a1%88%e7%9a%84%e7%96%91%e9%97%ae","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=423751","title":{"rendered":"\u5173\u4e8e N+1 \u95ee\u9898\u89e3\u51b3\u65b9\u6848\u7684\u7591\u95ee"},"content":{"rendered":"
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\u5173\u4e8e N+1 \u95ee\u9898\u89e3\u51b3\u65b9\u6848\u7684\u7591\u95ee <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : SakuraSv <\/span> <\/i> 0<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
\u6700\u8fd1\u5728\u4f7f\u7528 Net.flix \u7684 DGS \u6846\u67b6\u5199\u4e00\u4e2a GraphQL \u670d\u52a1\uff0c\u56e0\u4e3a\u6211\u5bf9 GraphQL \u5b9e\u8df5\u7ecf\u9a8c\u4e0d\u662f\u5f88\u591a\uff0c\u56e0\u6b64\u5728\u5904\u7406 N+1 \u95ee\u9898\u65f6\u4ea7\u751f\u4e86\u4e00\u4e9b\u7591\u95ee\u3002
\u5728\u5b98\u65b9\u6587\u6863 Async Data Fetching \u4e00\u7ae0\u4e2d\uff08 https:\/\/net.flix.github.io\/dgs\/data-loaders\/\uff09\uff0cDGS \u63d0\u4f9b\u4e86 DgsDataLoader \u6765\u63d0\u4f9b\u5408\u6210\u67e5\u8be2\u7684\u65b9\u5f0f\u89e3\u51b3\u8be5\u95ee\u9898\u3002
\u5728\u6587\u6863\u53e6\u4e00\u7ae0 Nested data fetchers \uff08 https:\/\/net.flix.github.io\/dgs\/advanced\/context-passing\/\uff09\u7684 Pre-Loading \u90e8\u5206\u4e2d\u53c8\u4ecb\u7ecd\u4e86\u901a\u8fc7 DataFetchingEnvironment \u83b7\u53d6 SelectionSet \u5e76\u5224\u65ad\u67e5\u8be2\u8bed\u53e5\u4e2d\u662f\u5426\u6709\u8be5\u5b50\u5b57\u6bb5\u7684\u65b9\u5f0f\u63d0\u4f9b\u9884\u52a0\u8f7d\uff0c\u6211\u611f\u89c9\u8fd9\u4e2a\u65b9\u6cd5\u4e5f\u80fd\u89e3\u51b3 N+1 \u95ee\u9898\u3002
\u90a3\u4e48\u8fd9\u4e24\u79cd\u65b9\u6cd5\u6709\u4ec0\u4e48\u4e0d\u540c\u7684\u9002\u7528\u573a\u666f\u5417\uff0c\u8fd8\u662f\u6211\u5bf9\u4ed6\u4eec\u7406\u89e3\u6709\u95ee\u9898\u5462\uff1f
—
\u56e0\u4e3a\u7f51\u98de\u8fd9\u4e2a\u8bcd\u88ab\u5c4f\u853d\u4e86\uff0c\u6240\u4ee5\u4e0a\u9762\u94fe\u63a5 net \u548c flix \u90a3\u4e2a\u70b9\u8981\u5220\u6389 <\/div>\n
\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (5<\/span>) <\/div>\n
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    \n
  • \n
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    \u8cc7\u6df1\u5927\u4f6c : namelosw <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u53e6\u5916\u4e00\u4e2a\u6ca1\u7528\u8fc7\uff0c\u4e0d\u8fc7 GraphQL \u91cc\u9762\u5e38\u7528\u7684 Dataloader \u7684\u539f\u7406\u662f\u672c\u6765 lazy load \u7684\u65f6\u5019\u6253\u5230 Dataloader \u4e0a\uff0c\u8bb0\u4e0b id \u6700\u540e\u4e00\u6b21\u6267\u884c\uff0c\u672c\u8d28\u4e0a\u5e76\u4e0d\u662f\u76f4\u63a5\u89e3\u51b3 N + 1\uff0c\u800c\u662f\u628a N + 1 batch \u8d77\u6765\uff0c\u751f\u6210\u5f88\u5927\u7684 SELECT IN (1, 2, 3 …)\u3002<\/p>\n

    \u800c\u6700\u5e38\u89c1\u9632\u6b62 N + 1 \u7684\u65b9\u5f0f\u5c31\u662f\u5173\u95ed Lazy load\uff0c\u7136\u540e\u624b\u52a8 prefetch \u2014\u2014 \u6548\u679c\u662f\u653e\u5728\u4e00\u6761 join \u91cc\uff0c\u6bd4\u4e0a\u9762\u4e00\u79cd\u65b9\u6cd5\u8981\u9ad8\u6548\uff0c\u4f46\u662f\u7a0b\u5e8f\u5458\u7684\u6d3b\u591a\u4e86\u3002<\/p>\n

    \u6211\u731c\u6700\u7406\u60f3\u7684\u65b9\u5f0f\u662f\u7528\u7c7b\u4f3c\u7a0b\u5e8f\u5206\u6790\u7684\u5f62\u5f0f\u628a N + 1 \u8f6c\u5316\u6210 join \u800c\u975e batch\uff0c\u4e0d\u8fc7\u611f\u89c9\u597d\u50cf\u5e76\u4e0d\u662f non-trivial \u7684\u95ee\u9898\uff0c\u5373\u4f7f\u80fd\u5b9e\u73b0\u9650\u5236\u4e5f\u5f88\u5f3a\u3002 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
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    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : SakuraSv <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @namelosw \u5176\u5b9e\u4e0a\u9762\u8bf4\u7684\u7b2c\u4e8c\u79cd\u65b9\u6cd5\uff08\u9884\u52a0\u8f7d\uff09\u5c31\u662f\u5229\u7528 Join \u7684\u529e\u6cd5\uff0c\u5148\u5224\u65ad\u4f60\u662f\u5426\u8981\u83b7\u53d6\u8fd9\u4e2a\u5b57\u6bb5\uff0c\u5982\u679c\u9700\u8981\u8fd9\u4e2a\u5b57\u6bb5\u5c31\u8c03\u7528\u7279\u5b9a\u7684 SQL \u8fdb\u884c\u7ea7\u8054\uff0c\u6240\u4ee5\u6211\u611f\u89c9\u8fd9\u4e24\u79cd\u65b9\u6cd5\u90fd\u53ef\u4ee5\uff0c\u4f46\u662f\u4e0d\u592a\u6e05\u695a\u5728\u5177\u4f53\u573a\u666f\u4e2d\u600e\u4e48\u53bb\u9009\u62e9\uff0c\u6240\u4ee5\u6765\u5411\u5927\u5bb6\u54a8\u8be2\u7ecf\u9a8c\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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    \u8cc7\u6df1\u5927\u4f6c : namelosw <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @SakuraSv GraphQL \u7684\u8bbe\u8ba1\u5bfc\u81f4\u4e86 N + 1 \u4e00\u4e0a\u6765\u5c31\u4f1a\u6ee1\u5929\u98de\uff0c\u4e0d\u53ef\u80fd\u5168\u624b\u52a8 join \u548c prefetch\uff0c\u6240\u4ee5 Dataloader \u662f\u7528 batch \u5e73\u8861\u6027\u80fd\u548c\u4ee3\u7801\u590d\u6742\u5ea6\u7684\u4e3b\u8981\u65b9\u5f0f\u3002<\/p>\n

    \u7b2c\u4e8c\u79cd\u7684\u95ee\u9898\u5c31\u662f\u6027\u80fd\u7a0d\u5fae\u597d\u4e00\u70b9\uff0c\u4e0d\u4f1a\u51fa\u73b0\u5de8\u578b SELECT IN \u3002\u4f46\u662f\u4f60\u9700\u8981\u624b\u52a8\u5148\u5e2e\u6846\u67b6 load \u4e00\u90e8\u5206\uff0c\u800c\u4e0d\u662f\u9760
    Dataloader \u81ea\u52a8\u5b8c\u6210\u7684\u3002<\/p>\n

    \u6211\u7406\u89e3\u573a\u666f\u7684\u8bdd\u5c31\u662f\u770b\u4f60\u6ce8\u91cd\u5f00\u53d1\u4f53\u9a8c\u53ef\u8bfb\u6027 (Dataloader)\uff0c\u8fd8\u662f\u6ce8\u91cd\u6027\u80fd\u4f18\u5316 (pre-loading)\u3002 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : SakuraSv <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @namelosw \u521a\u624d\u60f3\u5230\u53ef\u4ee5\u5229\u7528\u6570\u636e\u5e93\u7684\u89c6\u56fe\u6765\u95f4\u63a5\u5b9e\u73b0\u7b2c\u4e8c\u79cd\u65b9\u5f0f\uff0c\u867d\u7136\u6027\u80fd\u53ef\u80fd\u4f1a\u6bd4\u9009\u62e9\u6027 join \u66f4\u5dee\u4e00\u70b9\uff0c\u4f46\u662f\u53ef\u8bfb\u6027\u548c\u6027\u80fd\u5e94\u8be5\u80fd\u53d6\u5230\u4e00\u4e2a\u76f8\u5bf9\u5747\u8861\u7684\u70b9 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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    \u8cc7\u6df1\u5927\u4f6c : namelosw <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @SakuraSv <\/p>\n

    N + 1 \u662f application \u7684\u95ee\u9898\uff0c\u89c6\u56fe\u53ea\u662f\u5728\u6570\u636e\u5e93\u91cc\u9762\u7684\u4e1c\u897f\uff0c\u6211\u7406\u89e3\u5efa\u4e86\u89c6\u56fe application \u4e5f\u4e0d\u77e5\u9053\uff0c\u8fd8\u662f\u8981\u53d1 N + 1 \u6761 query\u2026 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n","protected":false},"excerpt":{"rendered":"

    \u5173\u4e8e N+1 \u95ee\u9898\u89e3\u51b3\u65b9\u6848\u7684\u7591\u95ee …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/423751"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=423751"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/423751\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=423751"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=423751"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=423751"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}