{"description":"\u3053\u308c\u3082\u3044\u307e\u307e\u3067\u898b\u904e\u3054\u3057\u3066\u3044\u305f\u2026 \u300cSELECT xxx FROM table_a WHERE xxx IN (SELECT xxx FROM table_b ...) \u300d\u3060\u3068\u3001table_a(xxx)\u306b\u5bfe\u3057\u3066 INDEX \u3092\u4f5c\u6210\u3057\u3066\u3042\u3063\u3066\u3082 Seq Scan \u306b\u306a\u3063\u3066\u3057\u307e\u3046\u2026\uff1f jcomi_db=# EXPLAIN ANALYZE SELECT COUNT(*) FROM t_author_info WHERE book_info_id IN (SELECT book_info_id FROM t_book_info WHERE book_title LIKE '%\u30e9\u30d6\u3072\u306a%'); QUERY\u2026","type":"rich","height":"190","width":"100%","categories":[],"provider_name":"Hatena Blog","author_name":"furyu-tei","blog_url":"https://memo.furyutei.com/","version":"1.0","provider_url":"https://hatena.blog","title":" PostgreSQL 9.x \u3067\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3046\u3068 Index Scan \u306b\u306a\u3089\u306a\u3044\uff1f","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fmemo.furyutei.com%2Fentry%2F20140120%2F1390226064\" title=\" PostgreSQL 9.x \u3067\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3046\u3068 Index Scan \u306b\u306a\u3089\u306a\u3044\uff1f - \u98a8\u67f3\u30e1\u30e2\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_url":"https://blog.hatena.ne.jp/furyu-tei/","url":"https://memo.furyutei.com/entry/20140120/1390226064","blog_title":"\u98a8\u67f3\u30e1\u30e2","image_url":null,"published":"2014-01-20 22:54:24"}