{"id":561,"date":"2021-02-26T17:03:45","date_gmt":"2021-02-26T08:03:45","guid":{"rendered":"http:\/\/www.opentone.co.jp\/ot-lab\/?p=561"},"modified":"2025-05-12T10:06:21","modified_gmt":"2025-05-12T01:06:21","slug":"mysql%e3%81%a7%e3%81%aesql%e3%83%81%e3%83%a5%e3%83%bc%e3%83%8b%e3%83%b3%e3%82%b0%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6%ef%bc%88explain%e3%81%ae%e8%a6%8b%e6%96%b9%e3%80%80%e3%81%9d%e3%81%ae%ef%bc%92","status":"publish","type":"post","link":"https:\/\/www.opentone.co.jp\/ot-lab\/all\/web-system\/mysql%e3%81%a7%e3%81%aesql%e3%83%81%e3%83%a5%e3%83%bc%e3%83%8b%e3%83%b3%e3%82%b0%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6%ef%bc%88explain%e3%81%ae%e8%a6%8b%e6%96%b9%e3%80%80%e3%81%9d%e3%81%ae%ef%bc%92","title":{"rendered":"MySQL\u3067\u306eSQL\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\u306b\u3064\u3044\u3066\uff08EXPLAIN\u306e\u898b\u65b9\u3000\u305d\u306e\uff12\uff09"},"content":{"rendered":"\n

MySql SQL\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0
\uff13\u56de\u76ee<\/p>\n\n\n\n

EXPLAIN\u306e\u898b\u65b9\u30fb\u30fb\u30fb\u7d9a\u304d\u3067\u3059<\/p>\n\n\n\n

possible_keys:
\u4f7f\u7528\u53ef\u80fd\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u8868\u3059\u3002
\u4f7f\u7528\u53ef\u80fd\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u5b58\u5728\u3057\u306a\u3044\u5834\u5408\u3001NULL\u304c\u8868\u793a\u3055\u308c\u308b\u3002
NULL\u304c\u8868\u793a\u3055\u308c\u305f\u5834\u5408\u306f\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u4f7f\u7528\u3055\u308c\u308b\u3088\u3046\u306b\u30af\u30a8\u30ea\u3092\u898b\u76f4\u3059\u304b\u3001
\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8a2d\u8a08\u3092\u898b\u76f4\u3059\u5fc5\u8981\u304c\u3042\u308b\u3002<\/p>\n\n\n\n

key:
\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u306e\u305f\u3081\u306b\u5b9f\u969b\u306b\u4f7f\u7528\u3057\u305f\u30ad\u30fc\u3092\u8868\u3059\u3002<\/p>\n\n\n\n

key_len:
\u4f7f\u7528\u3055\u308c\u305f\u30ad\u30fc\u306e\u9577\u3055\u3092\u793a\u3059\u3002
“key”\u306e\u5024\u304c\u8907\u5408\u30ad\u30fc\u3067\u3042\u3063\u305f\u5834\u5408\u3001\u5408\u8a08\u306e\u9577\u3055\u3092\u793a\u3059\u3002<\/p>\n\n\n\n

ref:
key\u306e\u5024\u3068\u7d50\u5408\u3059\u308b\u30ab\u30e9\u30e0\u3084\u5024\u3092\u793a\u3059\u3002
\u5024\u306e\u5834\u5408\u306f”const”\u3068\u8868\u793a\u3055\u308c\u3001\u30ab\u30e9\u30e0\u3067\u3042\u308c\u3070\u7d50\u5408\u306b\u4f7f\u7528\u3057\u305f\u30ab\u30e9\u30e0\u3092\u793a\u3059\u3002<\/p>\n\n\n\n

rows:
MySQL\u304c\u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3059\u308b\u305f\u3081\u306b\u8a55\u4fa1\u304c\u5fc5\u8981\u3060\u3068\u5224\u5b9a\u3057\u305f\u30ec\u30b3\u30fc\u30c9\u306e\u4ef6\u6570\u3002
innoDB\u306e\u5834\u5408\u306f\u6982\u7b97\u5024\u3068\u306a\u308a\u3001\u5fc5\u305a\u3057\u3082\u6b63\u3057\u3044\u5024\u304c\u793a\u3055\u308c\u308b\u3068\u306f\u9650\u3089\u306a\u3044\u3002<\/p>\n\n\n\n

filtered:
“EXPLAIN EXTENDED”\u3092\u4f7f\u7528\u3057\u305f\u5834\u5408\u306b\u8868\u793a\u3002
“EXPLAIN EXTENDED”\u306f5.1.12\u304b\u3089\u306e\u65b0\u6a5f\u80fd\u3002
\u7d50\u5408\u306b\u7528\u3044\u308b\u884c\u6570\u306e\u6bd4\u7387\uff08\u4e88\u6e2c\u5024\uff09\u3092\u8868\u3059\u3002<\/p>\n\n\n\n

Extra:
MySQL\u304c\u30af\u30a8\u30ea\u3092\u3069\u306e\u69d8\u306b\u51e6\u7406\u3059\u308b\u304b\u306e\u60c5\u5831\u3092\u51fa\u529b\u3059\u308b\u3002
\u3053\u306e\u5185\u5bb9\u304c\u7d50\u69cb\u809d\u306a\u306e\u3067\u3001
\u6b21\u56de\u3001\u3082\u3046\u5c11\u3057\u3044\u308d\u3044\u308d\u7814\u7a76\u3057\u3064\u3064\u8a18\u8ff0\u3057\u3066\u3044\u3053\u3046\u3068\u601d\u3044\u307e\u3059\u3002 <\/p>\n

\"\"<\/a><\/div>","protected":false},"excerpt":{"rendered":"

MySql SQL\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\uff13\u56de\u76ee EXPLAIN\u306e\u898b\u65b9\u30fb\u30fb\u30fb\u7d9a\u304d\u3067\u3059 possible_keys<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_uag_custom_page_level_css":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[28],"tags":[8],"class_list":["post-561","post","type-post","status-publish","format-standard","hentry","category-web-system","tag-blog",""],"acf":[],"aioseo_notices":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"engage-mag-carousel-img":false,"engage-mag-carousel-img-landscape":false,"engage-mag-carousel-large-img":false,"engage-mag-carousel-large-img-landscape":false,"engage-mag-large-thumb":false,"engage-mag-small-thumb":false},"uagb_author_info":{"display_name":"ah106rx4o4","author_link":"https:\/\/www.opentone.co.jp\/ot-lab\/author\/ah106rx4o4"},"uagb_comment_info":0,"uagb_excerpt":"MySql SQL\u30c1\u30e5\u30fc\u30cb\u30f3\u30b0\uff13\u56de\u76ee EXPLAIN\u306e\u898b\u65b9\u30fb\u30fb\u30fb\u7d9a\u304d\u3067\u3059 possible_keys","_links":{"self":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts\/561","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/comments?post=561"}],"version-history":[{"count":1,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts\/561\/revisions"}],"predecessor-version":[{"id":562,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts\/561\/revisions\/562"}],"wp:attachment":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/media?parent=561"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/categories?post=561"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/tags?post=561"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}