{"id":2686,"date":"2018-02-02T21:45:31","date_gmt":"2018-02-02T12:45:31","guid":{"rendered":"http:\/\/haisins.epac.to\/wordpress\/?p=2686"},"modified":"2018-02-02T21:45:31","modified_gmt":"2018-02-02T12:45:31","slug":"full-table-scan-%ec%9d%84-%eb%b9%a0%eb%a5%b4%ea%b2%8c-%ed%95%98%eb%8a%94-%eb%b0%a9%eb%b2%95","status":"publish","type":"post","link":"http:\/\/haisins.synology.me\/wordpress\/?p=2686","title":{"rendered":"FULL TABLE SCAN  \uc744  \ube60\ub974\uac8c \ud558\ub294 \ubc29\ubc95"},"content":{"rendered":"<div id=\"page\" class=\"hfeed site\">\n<div id=\"main\" class=\"clearfix\">\n<div class=\"inner-wrap clearfix\">\n<div class=\"main-content-section clearfix\">\n<div id=\"primary\">\n<div id=\"content\" class=\"clearfix\">\n<div class=\"article-container\">\n<div class=\"article-content clearfix\">\n<div class=\"entry-content clearfix\">\n<div>\n<div id=\"002cc41c-1d37-4115-8122-0d3f842a9dd3\" class=\"postBody\" contenteditable=\"true\">\n<p>* db_file_multiblock_read_count \ub294 Full Table Scan \uc2dc\uc5d0\ub9cc \uc601\ud5a5\uc744 \ubbf8\uce58\ub294 \ud30c\ub77c\ubbf8\ud130\uc774\ub2e4.<\/p>\n<p>\uc624\ub77c\ud074\uc758 \ucd5c\ub300 I\/O \ud06c\uae30\ub294 64KB \uc774\ubbc0\ub85c<\/p>\n<p>&nbsp;<\/p>\n<p>db_blocksize * db_file_multiblock_read_count &lt;= 64KB<\/p>\n<p>&nbsp;<\/p>\n<p>\uc774\uc5b4\uc57c \ud55c\ub2e4.<\/p>\n<p>Index\ub97c \uc774\uc6a9\ud55c Query \uc778 \uacbd\uc6b0\uc5d0\ub294 Full Table Scan \uacfc\ub294 \uc0c1\ud669\uc774 \ub2ec\ub77c\uc9c4\ub2e4. \uc774 \ub54c\uc5d0\ub294 db_block_size\uc758 \uc124\uc815\uc774 \uc911\uc694\ud558\ub2e4. \uc624\ub77c\ud074\uc740 \uc6d0\ud558\ub294 \ube14\ub7ed \ud06c\uae30\ub97c \uc120\ud0dd\ud560 \uc218 \uc788\uc73c\uba70 \ub300\ubd80\ubd84\uc758 \uc720\ub2c9\uc2a4 \ud658\uacbd\uc5d0\uc11c<\/p>\n<p>\ucd5c\ub300 8KB(\uc2dc\ud000\ud2b8\ub294 16KB)\uae4c\uc9c0 \uac00\ub2a5\ud558\ub2e4. \uac19\uc740 \ud06c\uae30\uc758 B-tree Index \uc5d0\uc11c \ube14\ub7ed\ud06c\uae30\uac00 8KB \ub77c\uba74 2KB \uc778 \uacbd\uc6b0\ubcf4\ub2e4 \uac70\uc758 4\ubc30 \ube68\ub9ac \ub370\uc774\ud0c0\ub97c \uc77d\uc5b4\ub4e4\uc774\uac8c \ub41c\ub2e4.<\/p>\n<p>\ud55c\ud3b8 Index Block \uc758 Pctfree\ub3c4 \uc911\uc694\ud55c \uc758\ubbf8\ub97c \uac16\ub294\ub370 \uc774 \uac12\uc774 \ub108\ubb34 \ud06c\uace0 \uc778\ub371\uc2a4\uc758 Entry Size \uac00 \ub298\uc5b4\ub098\uc9c0 \uc54a\uc73c\uba70 \uae30\uc874\uc758 \uc778\ub371\uc2a4 \uac12\uc5d0 \uc0c8\ub85c\uc6b4 \ub808\ucf54\ub4dc\uac00 \ub354 \uc774\uc0c1 \ucd94\uac00\ub418\uc9c0 \uc54a\ub294\ub2e4\uba74 \uacf5\uac04\uc758 \ub0ad\ube44\uac00 \uc2ec\ud558\uac8c \ub418\ubbc0\ub85c \uc801\uc808\ud55c \uac12\uc73c\ub85c \uc124\uc815\ud574\uc57c \ud55c\ub2e4.<\/p>\n<p>db_file_simultaneous_writes \ud30c\ub77c\ubbf8\ud130\ub294 \uc778\ub371\uc2a4\uc758 \uc7ac\uad6c\uc131\uc2dc \ud37c\ud3ec\uba3c\uc2a4\uc5d0 \ubcc4\ub85c \uc601\ud5a5\uc744 \ub07c\uce58\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>* db_file_multiblock_read_count \ub294 Full Table Scan \uc2dc\uc5d0\ub9cc \uc601\ud5a5\uc744 \ubbf8\uce58\ub294 \ud30c\ub77c\ubbf8\ud130\uc774\ub2e4. \uc624\ub77c\ud074\uc758 \ucd5c\ub300 I\/O \ud06c\uae30\ub294 64KB \uc774\ubbc0\ub85c &nbsp; db_blocksize * db_file_multiblock_read_count &lt;= 64KB &nbsp; \uc774\uc5b4\uc57c \ud55c\ub2e4. Index\ub97c \uc774\uc6a9\ud55c Query \uc778 \uacbd\uc6b0\uc5d0\ub294 Full Table Scan \uacfc\ub294 \uc0c1\ud669\uc774 \ub2ec\ub77c\uc9c4\ub2e4. \uc774 \ub54c\uc5d0\ub294 db_block_size\uc758 \uc124\uc815\uc774 \uc911\uc694\ud558\ub2e4. \uc624\ub77c\ud074\uc740 \uc6d0\ud558\ub294 \ube14\ub7ed \ud06c\uae30\ub97c \uc120\ud0dd\ud560 \uc218 \uc788\uc73c\uba70 \ub300\ubd80\ubd84\uc758 \uc720\ub2c9\uc2a4 \ud658\uacbd\uc5d0\uc11c \ucd5c\ub300 8KB(\uc2dc\ud000\ud2b8\ub294 16KB)\uae4c\uc9c0 \uac00\ub2a5\ud558\ub2e4. [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"spay_email":""},"categories":[11],"tags":[876,881],"jetpack_featured_media_url":"","amp_enabled":true,"_links":{"self":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2686"}],"collection":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2686"}],"version-history":[{"count":1,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2686\/revisions"}],"predecessor-version":[{"id":2687,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2686\/revisions\/2687"}],"wp:attachment":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2686"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}