{"id":1930,"date":"2020-03-13T23:08:16","date_gmt":"2020-03-13T14:08:16","guid":{"rendered":"https:\/\/oboki.net\/workspace\/?p=1930"},"modified":"2025-08-11T23:31:31","modified_gmt":"2025-08-11T14:31:31","slug":"do-not-trust-impala-optimizer","status":"publish","type":"post","link":"https:\/\/oboki.net\/workspace\/data-engineering\/database\/impala\/do-not-trust-impala-optimizer\/","title":{"rendered":"\uc784\ud314\ub77c \uc635\ud2f0\ub9c8\uc774\uc800\ub97c \ubbff\uc9c0 \uc54a\uc744 \uac83"},"content":{"rendered":"<p>\uc784\ud314\ub77c\uc5d0\ub294 \uc870\uc778 \ud78c\ud2b8 \uc678\uc5d0\ub294 \uc870\ud68c \uc131\ub2a5 \uac1c\uc120\uc744 \uc704\ud55c \ud78c\ud2b8\uac00 \ud2b9\ubcc4\ud788 \uc5c6\ub2e4. \uc784\uc2dc \ud14c\uc774\ube14\ub85c \ucc98\ub9ac \ub2e8\uacc4\ub97c \ub098\ub204\ub294 \ubc29\ubc95\uc774 \uadf8\ub098\ub9c8 \ud655\uc2e4\ud55c \ubc29\ubc95\uc778\ub370 \uc774\uac74 \uc57d\uac04 \ubc88\uac70\ub86d\ub2e4.<\/p>\n<p>\uc870\uc778 \ubc29\uc2dd\uc740 Broadcast join (<code>\/*+ broadcast *\/<\/code>) \uc774 \uae30\ubcf8\uc778\ub370, Partitioned join (<code>\/*+ shuffle *\/<\/code>) \uc73c\ub85c \ub3d9\uc791\ud558\ub3c4\ub85d \uba85\uc2dc\uc801\uc73c\ub85c \ud78c\ud2b8\ub85c \uc81c\uc5b4\ud560 \uc218 \uc788\ub2e4.<\/p>\n<p><code>SET DEFAULT_JOIN_DISTRIBUTION_MODE=shuffle;<\/code> \uc640 \uac19\uc774 \ud30c\ub77c\ubbf8\ud130\ub85c \uae30\ubcf8\uac12\uc774 \ub2e4\ub974\uac8c \uc124\uc815\ub3fc\uc788\uc744 \uc218\ub3c4 \uc788\uc73c\ub2c8 \uba85\uc2dc\uc801\uc73c\ub85c \ud78c\ud2b8\ub97c \uae30\uc7ac\ud558\ub294\uac8c \uc88b\uc744 \uac83\ub3c4 \uac19\ub2e4.<\/p>\n<p>\uc635\ud2f0\ub9c8\uc774\uc800\ub97c \ubbff\uace0 \uc544\ubb34\ub7f0 \ud78c\ud2b8 \uc0ac\uc6a9 \uc5c6\uc774 \uc4f0\ub294\uac8c \uc774\uc0c1\uc801\uc774\uaca0\uc9c0\ub9cc \ud55c\ubc88\uc529 \uc815\ub9d0 \uc774\uc0c1\ud55c \ud50c\ub79c\uc744 \ub9cc\ub4e4\uc5b4\uc904 \ub54c\ub3c4 \uc788\ub2e4.<\/p>\n<p>\uadf8\ub7f4\ub550 <code>STRAIGHT_JOIN<\/code> \uc73c\ub85c \uc870\uc778 \uc21c\uc11c\ub97c \uace0\uc815\uc2dc\ud0a4\uace0 \ub4dc\ub77c\uc774\ube59 \ud14c\uc774\ube14\ubd80\ud130 \ud06c\uae30\uac00 \uc791\uc740 \uc21c\uc11c\ub300\ub85c \uc815\ub82c\ud574\ubcfc \uac83.<\/p>\n<p><a href=\"https:\/\/docs.cloudera.com\/best-practices\/latest\/impala-performance\/topics\/bp-impala-join-query-performance-tuning.html\">https:\/\/docs.cloudera.com\/best-practices\/latest\/impala-performance\/topics\/bp-impala-join-query-performance-tuning.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\uc784\ud314\ub77c\uc5d0\ub294 \uc870\uc778 \ud78c\ud2b8 \uc678\uc5d0\ub294 \uc870\ud68c \uc131\ub2a5 \uac1c\uc120\uc744 \uc704\ud55c \ud78c\ud2b8\uac00 \ud2b9\ubcc4\ud788 \uc5c6\ub2e4. \uc784\uc2dc \ud14c\uc774\ube14\ub85c \ucc98\ub9ac \ub2e8\uacc4\ub97c \ub098\ub204\ub294 \ubc29\ubc95\uc774 \uadf8\ub098\ub9c8 \ud655\uc2e4\ud55c \ubc29\ubc95\uc778\ub370 \uc774\uac74 \uc57d\uac04 \ubc88\uac70\ub86d\ub2e4. \uc870\uc778 \ubc29\uc2dd\uc740 Broadcast join (\/*+ broadcast *\/) \uc774 \uae30\ubcf8\uc778\ub370, Partitioned join (\/*+ shuffle *\/) \uc73c\ub85c \ub3d9\uc791\ud558\ub3c4\ub85d \uba85\uc2dc\uc801\uc73c\ub85c \ud78c\ud2b8\ub85c \uc81c\uc5b4\ud560 \uc218 \uc788\ub2e4. SET DEFAULT_JOIN_DISTRIBUTION_MODE=shuffle; \uc640 \uac19\uc774 \ud30c\ub77c\ubbf8\ud130\ub85c \uae30\ubcf8\uac12\uc774 \ub2e4\ub974\uac8c \uc124\uc815\ub3fc\uc788\uc744 \uc218\ub3c4 \uc788\uc73c\ub2c8 \uba85\uc2dc\uc801\uc73c\ub85c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[161],"tags":[],"class_list":["post-1930","post","type-post","status-publish","format-standard","hentry","category-impala"],"_links":{"self":[{"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/posts\/1930","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/comments?post=1930"}],"version-history":[{"count":0,"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/posts\/1930\/revisions"}],"wp:attachment":[{"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/media?parent=1930"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/categories?post=1930"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/oboki.net\/workspace\/wp-json\/wp\/v2\/tags?post=1930"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}