{"id":9236,"date":"2022-06-20T16:30:18","date_gmt":"2022-06-20T08:30:18","guid":{"rendered":"https:\/\/www.gbase8.cn\/?p=9236"},"modified":"2022-06-20T16:30:18","modified_gmt":"2022-06-20T08:30:18","slug":"gbase-8a%e7%9b%b8%e5%90%8c%e5%ad%90%e6%9f%a5%e8%af%a2%e5%a4%9a%e6%ac%a1%e4%bd%bf%e7%94%a8%e7%9a%84%e4%bc%98%e5%8c%96%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.gbase8.cn\/en\/9236","title":{"rendered":"\u5357\u5927\u901a\u7528GBase 8a\u76f8\u540c\u5b50\u67e5\u8be2\u591a\u6b21\u4f7f\u7528\u7684\u4f18\u5316\u65b9\u6cd5"},"content":{"rendered":"<p>\u5728GBase 8a\u4e2d\uff0c\u4f1a\u5c06\u5b50\u67e5\u8be2\u4fdd\u5b58\u5230\u4e34\u65f6\u8868\u91cc\u3002 \u5982\u679c\u591a\u4e2a\u5b50\u67e5\u8be2\u662f\u5b8c\u5168\u76f8\u540c\u7684\uff0c\u5219\u4f1a\u5bfc\u81f4\u8d44\u6e90\u6d6a\u8d39\u3002\u672c\u6587\u63d0\u4f9b\u4e86CTE\u548c\u53c2\u6570\u51712\u4e2a\u53ef\u884c\u65b9\u6848\u6765\u4f18\u5316\u8fd9\u4e2a\u573a\u666f\u3002<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Directory Navigation<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a2aaa66ee42f\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6a2aaa66ee42f\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E5%9C%BA%E6%99%AF\" >\u573a\u666f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E4%BC%98%E5%8C%96%E6%96%B9%E6%A1%88\" >\u4f18\u5316\u65b9\u6848<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E9%87%87%E7%94%A8CTECommon_Table_Express\" >\u91c7\u7528CTE(Common Table Express)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E8%B0%83%E6%95%B4%E6%95%B0%E6%8D%AE%E5%BA%93%E5%8F%82%E6%95%B0\" >\u8c03\u6574\u6570\u636e\u5e93\u53c2\u6570<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E9%BB%98%E8%AE%A4%E6%89%A7%E8%A1%8C%E8%AE%A1%E5%88%92\" >\u9ed8\u8ba4\u6267\u884c\u8ba1\u5212<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E5%BC%80%E5%90%AF%E5%8F%82%E6%95%B0%E5%90%8E%E7%9A%84%E6%89%A7%E8%A1%8C%E8%AE%A1%E5%88%92\" >\u5f00\u542f\u53c2\u6570\u540e\u7684\u6267\u884c\u8ba1\u5212<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.gbase8.cn\/en\/9236\/#%E6%80%BB%E7%BB%93\" >Summary<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%9C%BA%E6%99%AF\"><\/span>\u573a\u666f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u67d0\u4e2a\u5b50\u67e5\u8be2\u7684\u7ed3\u679c\uff0c\u4f1a\u88ab\u591a\u6b21\u4f7f\u7528\uff0c\u7c7b\u4f3c\u5982\u4e0b\u7684<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select XXX from (SubQueryA) ta\r\nunion all\r\nselect YYY from (SubQueryA) tb\r\nunion all\r\nselect ZZZ from (SubQueryA) tc<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E4%BC%98%E5%8C%96%E6%96%B9%E6%A1%88\"><\/span>\u4f18\u5316\u65b9\u6848<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E9%87%87%E7%94%A8CTECommon_Table_Express\"><\/span>\u91c7\u7528CTE(Common Table Express)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>SQL\u5c06\u4f18\u5316\u6210\u5982\u4e0b\u5199\u6cd5\uff0c\u8be5SQL\u5c06\u53ea\u6267\u884c\u4e00\u6b21\uff0c\u8282\u7701\u8d44\u6e90\uff0c\u540c\u65f6SQL\u8bed\u53e5\u4e5f\u66f4\u6613\u8bfb\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>with t as SubQueryA\nselect XXX from t\r\nunion all\r\nselect YYY from t\r\nunion all\r\nselect ZZZ from t<\/code><\/pre>\n\n\n\n<p>\u53c2\u8003 <a href=\"https:\/\/www.gbase8.cn\/en\/1078\/?hilite=cte\">GBase 8a \u652f\u6301<mark>CTE<\/mark>\u00a0\u529f\u80fdwith as \u4ecb\u7ecd<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%B0%83%E6%95%B4%E6%95%B0%E6%8D%AE%E5%BA%93%E5%8F%82%E6%95%B0\"><\/span>\u8c03\u6574\u6570\u636e\u5e93\u53c2\u6570<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>CTE\u65b9\u6cd5\u9700\u8981\u91cd\u5199SQL\u8bed\u53e5\uff0c\u5982\u679c\u5df2\u4e0a\u7ebf\u7684\u7cfb\u7edf\uff0c\u77ed\u65f6\u95f4\u5185\u65e0\u6cd5\u6539\u5199\uff0c\u53ef\u4ee5\u901a\u8fc7\u6570\u636e\u5e93\u7684\u53c2\u6570\u6765\u3010\u590d\u7528\u3011\u4e34\u65f6\u8868\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>_t_gcluster_reuse_tmp_table_optimize<\/code><\/pre>\n\n\n\n<p>\u8be5\u53c2\u6570\u9ed8\u8ba4\u4e3a0\uff0c\u5173\u95ed\uff0c\u8bbe\u7f6e\u4e3a2From\u5b50\u67e5\u8be2\u53ef\u4ee5\u590d\u7528\u3002<\/p>\n\n\n\n<p>\u652f\u6301session \u7ea7\u3002<\/p>\n\n\n\n<p>\u5982\u4e0b\u662f\u5f00\u542f\u524d\u548c\u5f00\u542f\u540e\u7684\u6267\u884c\u8ba1\u5212\u5bf9\u6bd4<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E9%BB%98%E8%AE%A4%E6%89%A7%E8%A1%8C%E8%AE%A1%E5%88%92\"><\/span>\u9ed8\u8ba4\u6267\u884c\u8ba1\u5212<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u6b65\u9aa40\u548c\u6b65\u9aa41\u662f\u5404\u81ea\u72ec\u7acb\u8fd0\u884c\u7684\uff0c\u751f\u6210\u4e862\u4e2a\u4e34\u65f6\u8868\uff0c\u6b65\u9aa42\u5c060\u548c1\u7684\u4e34\u65f6\u8868\u505a\u4e86\u6700\u7ec8\u5904\u7406\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code has-small-font-size\"><code>gbase> explain select sum(id) from (select id,count(*) cnt from t1 group by id) t1 union all  select sum(cnt) from (select id,count(*) cnt from t1 group by id) t1 ;\r\n+----+----------+------------+--------+-------------+\r\n| ID | MOTION   | OPERATION  | TABLE  | CONDITION   |\r\n+----+----------+------------+--------+-------------+\r\n| 02 | &#91;RESULT] |  Step      | &lt;00>   |             |\r\n|    |          |  AGG       |        |             |\r\n|    |          |  UNION ALL |        |             |\r\n|    |          |  Step      | &lt;01>   |             |\r\n|    |          |  AGG       |        |             |\r\n| 01 | &#91;GATHER] |  SubQuery3 | t1     |             |\r\n|    |          |   Table    | t1&#91;id] |             |\r\n|    |          |   GROUP    |        | GROUP BY id |\r\n|    |          |  AGG       |        |             |\r\n| 00 | &#91;GATHER] |  SubQuery1 | t1     |             |\r\n|    |          |   Table    | t1&#91;id] |             |\r\n|    |          |   GROUP    |        | GROUP BY id |\r\n|    |          |  AGG       |        |             |\r\n+----+----------+------------+--------+-------------+\r\n13 rows in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%BC%80%E5%90%AF%E5%8F%82%E6%95%B0%E5%90%8E%E7%9A%84%E6%89%A7%E8%A1%8C%E8%AE%A1%E5%88%92\"><\/span>\u5f00\u542f\u53c2\u6570\u540e\u7684\u6267\u884c\u8ba1\u5212<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u5b50\u67e5\u8be2\u4f1a\u5148\u6267\u884c\uff0c\u751f\u6210\u4e34\u65f6\u88680\uff0c \u7136\u540e\u4e24\u90e8\u5206\u5404\u81ea\u57280\u7684\u4e34\u65f6\u8868\u7684\u57fa\u7840\u4e0a\uff0c\u6267\u884c\u67e5\u8be2\uff0c\u5e76\u751f\u621001\uff0c02\u7684\u4e34\u65f6\u8868\uff0c\u6700\u540e03\u5c0601\u548c02\u6c47\u603b\u5f97\u5230\u7ed3\u679c\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code has-small-font-size\"><code>gbase> explain select sum(id) from (select id,count(*) cnt from t1 group by id) t1 union all  select sum(cnt) from (select id,count(*) cnt from t1 group by id) t1 ;\r\n+----+-------------+------------+--------+-------------+\r\n| ID | MOTION      | OPERATION  | TABLE  | CONDITION   |\r\n+----+-------------+------------+--------+-------------+\r\n| 03 | &#91;RESULT]    |  Step      | &lt;01>   |             |\r\n|    |             |  AGG       |        |             |\r\n|    |             |  UNION ALL |        |             |\r\n|    |             |  Step      | &lt;02>   |             |\r\n|    |             |  AGG       |        |             |\r\n| 02 | &#91;GATHER]    |  Step      | &lt;00>   |             |\r\n|    |             |  AGG       |        |             |\r\n| 01 | &#91;GATHER]    |  Step      | &lt;00>   |             |\r\n|    |             |  AGG       |        |             |\r\n| 00 | &#91;NO REDIST] |  Table     | t1&#91;id] |             |\r\n|    |             |  GROUP     |        | GROUP BY id |\r\n+----+-------------+------------+--------+-------------+\r\n11 rows in set (Elapsed: 00:00:00.01)\r\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%80%BB%E7%BB%93\"><\/span>Summary<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u5bf9\u4e8e\u67e5\u8be2\u7684\u590d\u7528\uff0c\u7279\u522b\u662f\u8017\u65f6\u8f83\u4e45\u7684\uff0c\u5efa\u8bae\u7528CTE\u65b9\u6848\u6539\u5199\u3002 \u77ed\u671f\u5185\u53ef\u4ee5\u8003\u8651\u6570\u636e\u5e93\u53c2\u6570\u3002<\/p>","protected":false},"excerpt":{"rendered":"<p>\u5728GBase 8a\u4e2d\uff0c\u4f1a\u5c06\u5b50\u67e5\u8be2\u4fdd\u5b58\u5230\u4e34\u65f6\u8868\u91cc\u3002 \u5982\u679c\u591a\u4e2a\u5b50\u67e5\u8be2\u662f\u5b8c\u5168\u76f8\u540c\u7684\uff0c\u5219\u4f1a\u5bfc\u81f4\u8d44\u6e90\u6d6a\u8d39\u3002\u672c\u6587\u63d0\u4f9b\u4e86CTE\u548c\u53c2\u6570\u51712\u4e2a\u53ef\u884c\u65b9\u6848\u6765\u4f18\u5316\u8fd9\u4e2a\u573a\u666f\u3002<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-9236","post","type-post","status-publish","format-standard","hentry","category-gbase8a"],"_links":{"self":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/9236","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/comments?post=9236"}],"version-history":[{"count":26,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/9236\/revisions"}],"predecessor-version":[{"id":9726,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/9236\/revisions\/9726"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=9236"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=9236"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=9236"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}