{"id":512,"date":"2026-05-17T07:04:21","date_gmt":"2026-05-16T23:04:21","guid":{"rendered":"https:\/\/junai.ai\/blog\/pg-explain-17\/"},"modified":"2026-05-17T07:04:21","modified_gmt":"2026-05-16T23:04:21","slug":"pg-explain-17","status":"publish","type":"post","link":"https:\/\/junai.ai\/blog\/pg-explain-17\/","title":{"rendered":"EXPLAIN ANALYZE \u2014 \uc2e4\ud589 \uacc4\ud68d \uc77d\uae30 (\uc911\uae09 17\ud3b8)"},"content":{"rendered":"\n<!-- WordPress REST API \ubc1c\ud589\uc6a9 HTML (\uc790\ub3d9 \uc0dd\uc131) -->\n<!-- WP-FEATURED-MEDIA-ID: 305 -->\n<div style=\"max-width:800px;margin:0 auto;\">\n<style>\n:root{--color-primary:#336791;--color-accent:#60a5fa;--color-bg:#fafafa;--color-bg-card:#ffffff;--color-text:#1e293b;--color-text-muted:#64748b;--hero-start:#0f172a;--hero-end:#336791;--font-body:-apple-system,BlinkMacSystemFont,'Apple SD Gothic Neo','Noto Sans KR',sans-serif;--size-body:17px;--line-height:1.75;}\n*{box-sizing:border-box;}\n.container{max-width:760px;margin:0 auto;padding:0 22px 80px;}\n.hero{background:linear-gradient(135deg,var(--hero-start) 0%,var(--hero-end) 100%);color:#fff;padding:72px 22px 56px;text-align:center;}\n.hero .badge{display:inline-block;background:rgba(96,165,250,0.18);color:var(--color-accent);padding:6px 14px;border-radius:999px;font-size:13px;font-weight:600;letter-spacing:0.5px;margin-bottom:18px;}\n.hero h1{margin:0 0 18px;font-size:36px;line-height:1.3;letter-spacing:-0.3px;}\n.hero p.sub{margin:0 auto;max-width:580px;font-size:17px;color:#bfdbfe;}\n.hero img{width:100%;max-width:720px;height:auto;margin:36px auto 0;display:block;border-radius:10px;box-shadow:0 8px 32px rgba(0,0,0,0.3);}\n.meta{display:flex;gap:14px;justify-content:center;margin-top:20px;font-size:13px;color:#93c5fd;flex-wrap:wrap;}\n.meta span::before{content:\"\u00b7\";margin-right:14px;color:#1e3a8a;}\n.meta span:first-child::before{content:\"\";margin:0;}\narticle{background:var(--color-bg-card);margin-top:-36px;padding:44px 28px;border-radius:14px;box-shadow:0 2px 18px rgba(0,0,0,0.06);}\narticle p{margin:0 0 18px;}\nh2{font-size:28px;line-height:1.35;letter-spacing:-0.3px;margin:48px 0 18px;padding-bottom:10px;border-bottom:2px solid var(--color-primary);}\nh2:first-of-type{margin-top:8px;}\nh3{font-size:21px;line-height:1.4;margin:30px 0 12px;color:var(--color-primary);}\ncode{background:#f1f5f9;color:#0f172a;padding:2px 6px;border-radius:4px;font-family:'SFMono-Regular',Menlo,Consolas,monospace;font-size:0.92em;}\npre{background:#0f172a;color:#e2e8f0;padding:18px 20px;border-radius:10px;overflow-x:auto;font-size:14.5px;line-height:1.65;margin:18px 0;}\npre code{background:transparent;color:inherit;padding:0;}\nul,ol{margin:0 0 18px;padding-left:24px;}\nli{margin-bottom:8px;}\nstrong{color:#0f172a;}\n.databox{background:#eff6ff;border-left:4px solid var(--color-primary);padding:18px 20px;border-radius:6px;margin:22px 0;}\n.databox p{margin:0 0 8px;}\n.databox p:last-child{margin:0;}\n.databox strong{color:var(--color-primary);}\n.warnbox{background:linear-gradient(135deg,#fef3c7 0%,#fde68a 100%);border-left:4px solid #d97706;padding:18px 20px;border-radius:6px;margin:22px 0;}\n.warnbox strong{color:#92400e;}\n.tablewrap{overflow-x:auto;-webkit-overflow-scrolling:touch;margin:22px 0;}\ntable{width:100%;border-collapse:collapse;font-size:15px;background:var(--color-bg-card);}\nth,td{padding:11px 12px;text-align:left;border-bottom:1px solid #e2e8f0;vertical-align:top;}\nth{background:#f1f5f9;font-weight:700;color:#0f172a;}\ntd:first-child,th:first-child{font-weight:700;}\n.cta{background:linear-gradient(135deg,#336791 0%,#60a5fa 100%);color:#fff;padding:30px 24px;border-radius:12px;margin-top:44px;text-align:center;}\n.cta h3{color:#fff;margin:0 0 10px;}\n.cta p{margin:0;color:#dbeafe;}\n.series-nav{background:#eff6ff;padding:18px 22px;border-radius:10px;margin-top:24px;font-size:14.5px;color:var(--color-text-muted);}\n.series-nav strong{color:var(--color-primary);}\n@media (max-width:480px){.hero{padding:52px 18px 44px;}.hero h1{font-size:26px;}.hero p.sub{font-size:15px;}article{padding:28px 18px;border-radius:10px;}h2{font-size:22px;}h3{font-size:18px;}body{font-size:16px;}pre{font-size:13px;padding:14px 16px;}}\n@media (max-width:560px){.tablewrap table,.tablewrap thead,.tablewrap tbody,.tablewrap tr,.tablewrap th,.tablewrap td{display:block;width:auto;}.tablewrap thead{display:none;}.tablewrap tr{margin:0 0 14px;border:1px solid #e2e8f0;border-radius:10px;overflow:hidden;}.tablewrap td{border:none;border-bottom:1px solid #f1f5f9;padding:9px 14px;}.tablewrap td:first-child{background:#eff6ff;font-weight:800;font-size:15.5px;}.tablewrap td:last-child{border-bottom:none;}.tablewrap td[data-label]::before{content:attr(data-label) \" \u2014 \";font-weight:700;color:var(--color-primary);}}\n<\/style>\n<header class=\"hero\">\n  <span class=\"badge\">PostgreSQL \uad50\uc7ac \u00b7 17\ud3b8 \/ 24\ud3b8<\/span>\n  <h1>EXPLAIN \u2014 \uc2e4\ud589 \uacc4\ud68d \uc77d\uae30<\/h1>\n  <p class=\"sub\">&#8220;\uc65c \ub290\ub9b0\uac00&#8221; \uc758 \ub2f5\uc774 \ub4e4\uc5b4\uc788\ub294 \ub3c4\uad6c. \uc2a4\uce94 \uc885\ub958\uc640 \ube44\uc6a9 \uc77d\uae30.<\/p>\n  <div class=\"meta\"><span>\uc911\uae09<\/span><span>\uc77d\ub294 \uc2dc\uac04 8\ubd84<\/span><span>2026-05-17<\/span><\/div>\n  <img decoding=\"async\" src=\"https:\/\/junai.ai\/blog\/wp-content\/uploads\/2026\/05\/hero-84.jpg\" alt=\"EXPLAIN \uc758 \ud2b8\ub9ac \uad6c\uc870\uc640 \uac01 \ub178\ub4dc\uc758 \ube44\uc6a9\u00b7\uc2dc\uac04\uc774 \ud45c\uc2dc\ub41c \ub3c4\uc2dd\">\n<\/header>\n\n<div class=\"container\">\n<article>\n\n<p>16\ud3b8\uc5d0\uc11c \uc778\ub371\uc2a4\ub97c \ub9cc\ub4e4\uc5c8\uc5b4\ub3c4 <strong>\uc635\ud2f0\ub9c8\uc774\uc800\uac00 \uadf8\uac78 \uc4f8\uc9c0<\/strong> \ub294 \ubcc4\uac1c. <strong>EXPLAIN<\/strong> \uc740 &#8220;\uc774 \ucffc\ub9ac\ub97c \uc5b4\ub5bb\uac8c \uc2e4\ud589\ud560 \uc0dd\uac01\uc778\uc9c0&#8221; \ubcf4\uc5ec\uc90d\ub2c8\ub2e4. 17\ud3b8\uc740 EXPLAIN \ucd9c\ub825 \ud2b8\ub9ac \uc77d\uae30, \uc2a4\uce94 \uc885\ub958 5\uac1c, \uadf8\ub9ac\uace0 ANALYZE \ub85c \uc2e4\uc81c \uce21\uc815\uae4c\uc9c0.<\/p>\n\n<h2>EXPLAIN \u2014 \uacc4\ud68d\ub9cc (\uc2e4\ud589 \uc548 \ud568)<\/h2>\n\n<pre><code>EXPLAIN SELECT * FROM users WHERE email = 'x@y.com';\n\n                            QUERY PLAN\n\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n Index Scan using ix_users_email on users  (cost=0.29..8.30 rows=1 width=80)\n   Index Cond: (email = 'x@y.com'::text)<\/code><\/pre>\n\n<p>\uc77d\ub294 \ubc95:<\/p>\n\n<ul>\n  <li><strong>Index Scan using ix_users_email<\/strong> \u2014 \uc5b4\ub5a4 \uc778\ub371\uc2a4\ub97c \uc4f0\ub294\uc9c0<\/li>\n  <li><strong>cost=0.29..8.30<\/strong> \u2014 (\uc2dc\uc791 \ube44\uc6a9)..(\uc804\uccb4 \ube44\uc6a9), \ub2e8\uc704\ub294 &#8220;\ub514\uc2a4\ud06c \ud398\uc774\uc9c0 \uac00\uc838\uc624\uae30 \ud3c9\uade0 \ube44\uc6a9&#8221;<\/li>\n  <li><strong>rows=1<\/strong> \u2014 \uc635\ud2f0\ub9c8\uc774\uc800\uac00 \uc608\uce21\ud55c \uacb0\uacfc \ud589 \uc218<\/li>\n  <li><strong>width=80<\/strong> \u2014 \ud55c \ud589 \ud3c9\uade0 \ud06c\uae30 (bytes)<\/li>\n<\/ul>\n\n<h2>EXPLAIN ANALYZE \u2014 \uc2e4\uc81c\ub85c \uc2e4\ud589 + \uce21\uc815<\/h2>\n\n<pre><code>EXPLAIN ANALYZE\nSELECT * FROM users WHERE email = 'x@y.com';\n\n                            QUERY PLAN\n\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n Index Scan using ix_users_email on users\n   (cost=0.29..8.30 rows=1 width=80)\n   (actual time=0.012..0.014 rows=1 loops=1)\n   Index Cond: (email = 'x@y.com'::text)\n Planning Time: 0.123 ms\n Execution Time: 0.045 ms<\/code><\/pre>\n\n<div class=\"warnbox\">\n  <p><strong>ANALYZE \uc8fc\uc758.<\/strong> ANALYZE \ub294 <strong>\uc2e4\uc81c\ub85c \ucffc\ub9ac\ub97c \uc2e4\ud589<\/strong>\ud569\ub2c8\ub2e4. UPDATE\/DELETE \uc5d0 \uc4f0\uba74 \ub370\uc774\ud130\uac00 \uc9c4\uc9dc \ubc14\ub01c! \ud2b8\ub79c\uc7ad\uc158\uc73c\ub85c \uac10\uc2f8\uace0 ROLLBACK \uad8c\uc7a5:<\/p>\n  <p><code>BEGIN; EXPLAIN ANALYZE UPDATE ...; ROLLBACK;<\/code><\/p>\n<\/div>\n\n<h2>\uc2a4\uce94 \uc885\ub958 5\uac00\uc9c0<\/h2>\n\n<div class=\"tablewrap\">\n<table>\n  <thead>\n    <tr><th>\uc2a4\uce94<\/th><th>\uc758\ubbf8<\/th><th>\uc5b8\uc81c<\/th><\/tr>\n  <\/thead>\n  <tbody>\n    <tr><td data-label=\"\">Seq Scan<\/td><td data-label=\"\">\ud14c\uc774\ube14 \ud480\uc2a4\uce94<\/td><td data-label=\"\">\uc778\ub371\uc2a4 \uc5c6\uc74c \/ \uc791\uc740 \ud14c\uc774\ube14 \/ \ud589 \ube44\uc728 \ud07c<\/td><\/tr>\n    <tr><td data-label=\"\">Index Scan<\/td><td data-label=\"\">\uc778\ub371\uc2a4 \ub530\ub77c \ud589 \uac00\uc838\uc624\uae30<\/td><td data-label=\"\">\uc120\ud0dd\uc801 WHERE + \uc801\uc740 \ud589<\/td><\/tr>\n    <tr><td data-label=\"\">Index Only Scan<\/td><td data-label=\"\">\uc778\ub371\uc2a4\ub9cc\uc73c\ub85c \uc751\ub2f5 (\ud14c\uc774\ube14 \uc548 \ubd04)<\/td><td data-label=\"\">covering index (16\ud3b8 INCLUDE)<\/td><\/tr>\n    <tr><td data-label=\"\">Bitmap Index Scan + Bitmap Heap Scan<\/td><td data-label=\"\">\uc911\uac04 \uac1c\uc218 \ud589 (\uc218\ubc31~\uc218\ucc9c)<\/td><td data-label=\"\">Index \uc640 Seq \uc758 \uc911\uac04<\/td><\/tr>\n    <tr><td data-label=\"\">Parallel Seq Scan<\/td><td data-label=\"\">\ubcd1\ub82c \ud480\uc2a4\uce94<\/td><td data-label=\"\">\ud070 \ud14c\uc774\ube14 + \ubcd1\ub82c \uac00\ub2a5 \ucffc\ub9ac<\/td><\/tr>\n  <\/tbody>\n<\/table>\n<\/div>\n\n<div class=\"databox\">\n  <p><strong>Seq Scan \uc774 \ud56d\uc0c1 \ub098\uc05c \uac74 \uc544\ub2c8\ub2e4.<\/strong> \uc791\uc740 \ud14c\uc774\ube14(\uc218\ucc9c \ud589) \uc740 \uc778\ub371\uc2a4 \uac70\uce58\ub294 \uac83\ubcf4\ub2e4 \ud1b5\uc9f8\ub85c \uc77d\ub294 \uac8c \ub354 \ube60\ub97c \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc635\ud2f0\ub9c8\uc774\uc800\uac00 \uadf8\ub807\uac8c \ud310\ub2e8\ud558\uba74 \uadf8\uac8c \uc815\ub2f5.<\/p>\n<\/div>\n\n<h2>JOIN \uc54c\uace0\ub9ac\uc998 \u2014 Nested Loop \u00b7 Hash \u00b7 Merge<\/h2>\n\n<pre><code>EXPLAIN ANALYZE\nSELECT u.name, o.id\nFROM   users u\nJOIN   orders o ON o.user_id = u.id\nWHERE  u.active = true;\n\n-- \uc791\uc740 \uacb0\uacfc (\uc218\uc2ed \ud589)\nNested Loop\n  -&gt; Index Scan on users      -- \uc678\ubd80 (\uc801\uc740 \ud589)\n  -&gt; Index Scan on orders     -- \uac01 user \ub9c8\ub2e4 \uc778\ub371\uc2a4\ub85c orders \uac80\uc0c9\n\n-- \ud070 \uc591\ucabd\nHash Join\n  Hash Cond: (o.user_id = u.id)\n  -&gt; Seq Scan on orders\n  -&gt; Hash\n       -&gt; Seq Scan on users\n\n-- \uc591\ucabd \ubbf8\ub9ac \uc815\ub82c\ub3fc \uc788\uc74c (\uc608: PK)\nMerge Join\n  -&gt; Index Scan on users\n  -&gt; Index Scan on orders<\/code><\/pre>\n\n<h2>\uc608\uc0c1 vs \uc2e4\uc81c \u2014 \ud1b5\uacc4 \uc5b4\uae0b\ub0a8 \uc9c4\ub2e8<\/h2>\n\n<pre><code>-&gt; Index Scan on big_table\n   (cost=0.42..8.50 rows=10 width=80)\n   (actual time=0.5..120.0 rows=50000 loops=1)\n   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n   \uc608\uc0c1 10 \ud589 vs \uc2e4\uc81c 50000 \ud589 \u2014 \ud1b5\uacc4 \uc5b4\uae0b\ub0a8!<\/code><\/pre>\n\n<p>\uc635\ud2f0\ub9c8\uc774\uc800\ub294 <strong>\ud1b5\uacc4 \uc815\ubcf4<\/strong> \ub97c \ubcf4\uace0 \uacc4\ud68d\uc744 \uc138\uc6c1\ub2c8\ub2e4. \ud1b5\uacc4\uac00 \uc624\ub798\ub418\uba74 \uc798\ubabb\ub41c \uacc4\ud68d \uc120\ud0dd. \ud574\uacb0:<\/p>\n\n<pre><code>ANALYZE big_table;     -- \ud1b5\uacc4 \uc7ac\uc218\uc9d1\n-- autovacuum \uc774 \ubcf4\ud1b5 \uc790\ub3d9, \ud070 INSERT \uc9c1\ud6c4\uc5d4 \uc218\ub3d9<\/code><\/pre>\n\n<h2>BUFFERS \uc635\uc158 \u2014 IO \ud655\uc778<\/h2>\n\n<pre><code>EXPLAIN (ANALYZE, BUFFERS)\nSELECT ...;\n\n-- Buffers: shared hit=120 read=45\n--          ^ \uba54\ubaa8\ub9ac\uc5d0 \uc788\ub358 \ud398\uc774\uc9c0 \/ \ub514\uc2a4\ud06c\uc5d0\uc11c \uc77d\uc740 \ud398\uc774\uc9c0\n-- read \uac00 \ud06c\uba74 IO \ubcd1\ubaa9, hit \uac00 \ud06c\uba74 \uce90\uc2dc OK<\/code><\/pre>\n\n<h2>JSON \ud3ec\ub9f7 \u2014 \uc2dc\uac01\ud654 \ub3c4\uad6c<\/h2>\n\n<pre><code>EXPLAIN (ANALYZE, BUFFERS, FORMAT JSON)\nSELECT ...;\n\n-- \uacb0\uacfc\ub97c https:\/\/explain.dalibo.com \uac19\uc740 \ub3c4\uad6c\uc5d0 \ubd99\uc5ec \uc2dc\uac01\ud654<\/code><\/pre>\n\n<div class=\"databox\">\n  <p><strong>\uc2e4\uc804 \ub3c4\uad6c.<\/strong> \ud070 EXPLAIN \ucd9c\ub825\uc740 \ud14d\uc2a4\ud2b8\ub85c \uc77d\uae30 \uc5b4\ub824\uc6c0. <strong>dalibo<\/strong>\u00b7<strong>pg_explain<\/strong> \uac19\uc740 \uc6f9 \ub3c4\uad6c\uc5d0 JSON \uacb0\uacfc \ubd99\uc774\uba74 \ud2b8\ub9ac \uadf8\ub9bc\uc73c\ub85c \ubcf4\uc785\ub2c8\ub2e4. \ube44\uc2fc \ub178\ub4dc\uac00 \ud55c\ub208\uc5d0.<\/p>\n<\/div>\n\n<h2>\ud754\ud55c \ud328\ud134 \ubd84\uc11d<\/h2>\n\n<h3>\u2460 WHERE \uc5d0 \ud568\uc218 \u2014 \uc778\ub371\uc2a4 \ubb34\ub825\ud654<\/h3>\n\n<pre><code>-- \u274c \ud568\uc218\uac00 \uceec\ub7fc\uc5d0 \uc801\uc6a9\ub418\uba74 \uc778\ub371\uc2a4 \ubabb \uc500\nSELECT * FROM users WHERE lower(email) = 'x@y.com';\n-- \u2192 Seq Scan\n\n-- \u2705 \ud45c\ud604\uc2dd \uc778\ub371\uc2a4 (16\ud3b8)\nCREATE INDEX ix_users_email_lower ON users ((lower(email)));\n-- \ub610\ub294 \ub370\uc774\ud130 \uc790\uccb4\ub97c lowercase \ub85c \uc800\uc7a5<\/code><\/pre>\n\n<h3>\u2461 \ud615 \ubcc0\ud658 \u2014 \uc778\ub371\uc2a4 \ubb34\ub825\ud654<\/h3>\n\n<pre><code>-- id \uac00 bigint \uc778\ub370 \ubb38\uc790\uc5f4 \ube44\uad50\nSELECT * FROM users WHERE id = '5';   -- \uc554\ubb35\uc801 cast \u2192 Seq Scan \uc704\ud5d8\n\n-- \uba85\uc2dc\uc801\nSELECT * FROM users WHERE id = 5;     -- \ub610\ub294 $1::bigint<\/code><\/pre>\n\n<h3>\u2462 LIKE \uc55e \uc640\uc77c\ub4dc\uce74\ub4dc<\/h3>\n\n<pre><code>-- B-Tree \ubabb \uc500\nSELECT * FROM users WHERE name LIKE '%\uc900\uc131';\n\n-- 16\ud3b8\uc758 pg_trgm GIN \uc778\ub371\uc2a4 \ud544\uc694<\/code><\/pre>\n\n<h3>\u2463 OR \uc5ec\ub7ec \uceec\ub7fc<\/h3>\n\n<pre><code>SELECT * FROM users WHERE name = $1 OR email = $1;\n-- \ubcf4\ud1b5 \ub458 \ub2e4 Seq Scan\n\n-- \ubd84\ub9ac\ud574\uc11c UNION (\uac01\uac01 \uc778\ub371\uc2a4 \uc0ac\uc6a9)\nSELECT * FROM users WHERE name = $1\nUNION\nSELECT * FROM users WHERE email = $1;<\/code><\/pre>\n\n<h2>pg_stat_statements \u2014 \ub290\ub9b0 \ucffc\ub9ac \uc790\ub3d9 \ucd94\uc801<\/h2>\n\n<pre><code>CREATE EXTENSION pg_stat_statements;\n\n-- postgresql.conf\n-- shared_preload_libraries = 'pg_stat_statements'\n-- (\uc7ac\uc2dc\uc791 \ud544\uc694)\n\nSELECT query,\n       calls,\n       round(total_exec_time::numeric, 2) AS total_ms,\n       round(mean_exec_time::numeric, 2)  AS mean_ms,\n       rows\nFROM   pg_stat_statements\nORDER BY total_exec_time DESC\nLIMIT 10;<\/code><\/pre>\n\n<p>\uc6b4\uc601 \ud658\uacbd\uc5d0\uc11c\ub294 \uc774\uac8c \uac00\uc7a5 \uac15\ub825\ud55c \ub3c4\uad6c. &#8220;\ucd1d \uc2dc\uac04 \uac00\uc7a5 \ub9ce\uc774 \uc7a1\uc544\uba39\ub294 \ucffc\ub9ac 10\uac1c&#8221; \ub97c \uc790\ub3d9\uc73c\ub85c \uc54c\ub824\uc90d\ub2c8\ub2e4.<\/p>\n\n<h2>\ud55c \uc904 \uc9c4\ub2e8 \uccb4\ud06c\ub9ac\uc2a4\ud2b8<\/h2>\n\n<ul>\n  <li>Seq Scan \uc778\ub370 \ud070 \ud14c\uc774\ube14 \u2192 \uc778\ub371\uc2a4 \ubd80\uc7ac \ub610\ub294 \ud1b5\uacc4 \uc5b4\uae0b\ub0a8<\/li>\n  <li>\uc608\uc0c1 vs \uc2e4\uc81c \ud589 \uc218 10\ubc30 \uc774\uc0c1 \ucc28\uc774 \u2192 <code>ANALYZE<\/code> \ud544\uc694<\/li>\n  <li>BUFFERS read \uac00 \ud07c \u2192 IO \ubcd1\ubaa9, shared_buffers \ubd80\uc871 \uac00\ub2a5<\/li>\n  <li>cost \uc791\uc740\ub370 actual time \ud07c \u2192 \ub514\uc2a4\ud06c IO \ub610\ub294 \ub77d \ub300\uae30<\/li>\n  <li>Nested Loop + \ud070 \uc678\ubd80 \u2192 Hash Join \uc73c\ub85c \uc548 \ud480\ub9b0 \uc774\uc720 \ud655\uc778<\/li>\n<\/ul>\n\n<div class=\"cta\">\n  <h3>18\ud3b8 \u2014 \uc0ac\uc6a9\uc790 \uc815\uc758 \ud568\uc218 (SQL\u00b7PL\/pgSQL)<\/h3>\n  <p>CREATE FUNCTION, \uc5b8\uc5b4\ubcc4 \ucc28\uc774, \ud2b8\ub9ac\uac70 \ud568\uc218 \uc0b4\uc9dd.<\/p>\n<\/div>\n\n<div class=\"series-nav\">\n  <strong>\ud83d\udcda PostgreSQL \ubc30\uc6b0\uae30 \uad50\uc7ac<\/strong><br>\n  \uc774\uc804: 16\ud3b8 \uc778\ub371\uc2a4 \u00b7 \ud604\uc7ac: <strong>17\ud3b8 (\uc911\uae09)<\/strong> \u00b7 \ub2e4\uc74c \u2192 18\ud3b8 \ud568\uc218 \u00b7 \uc9c4\ud589: <strong>17\/24<\/strong>\n<\/div>\n\n<\/article>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>EXPLAIN \ud2b8\ub9ac\u00b7\uc2a4\uce94 \uc885\ub958\u00b7\uc2e4\uc81c \uc2dc\uac04 \uce21\uc815. 24\ud3b8 \uad50\uc7ac 17\ud3b8.<\/p>\n","protected":false},"author":1,"featured_media":305,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-512","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-postgresql"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/posts\/512","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/comments?post=512"}],"version-history":[{"count":0,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/posts\/512\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/media\/305"}],"wp:attachment":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/media?parent=512"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/categories?post=512"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/tags?post=512"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}