{"id":436,"date":"2015-09-03T04:53:47","date_gmt":"2015-09-03T04:53:47","guid":{"rendered":"http:\/\/haisins.epac.to\/wordpress\/?p=436"},"modified":"2015-09-03T04:53:47","modified_gmt":"2015-09-03T04:53:47","slug":"%ec%98%a4%eb%9d%bc%ed%81%b4-%ed%94%84%eb%a1%9c%ec%84%b8%ec%8a%a4%ea%b0%80-free-buffer-%eb%a5%bc-%ec%b0%be%eb%8a%94-%ea%b3%bc%ec%a0%95","status":"publish","type":"post","link":"http:\/\/haisins.synology.me\/wordpress\/?p=436","title":{"rendered":"\uc624\ub77c\ud074 \ud504\ub85c\uc138\uc2a4\uac00 Free Buffer \ub97c \ucc3e\ub294 \uacfc\uc815"},"content":{"rendered":"

– \uc624\ub77c\ud074 \ud504\ub85c\uc138\uc2a4\uac00 Free Buffer <\/span>\ub97c \ucc3e\ub294 \uacfc\uc815 –<\/span><\/b><\/p>\n


<\/span><\/b><\/p>\n

Database Buffer Cache<\/span><\/b><\/p>\n

\n

\ucd5c\uadfc\uc5d0 \uc0ac\uc6a9\ub41c
\n\ub370\uc774\ud0c0\ubca0\uc774\uc2a4\uc758 \ub370\uc774\ud0c0 \ube14\ub85d\uc744 \uc800\uc7a5\ud558\uace0 \uc788\ub294 Database Buffer <\/span>\uc601\uc5ed\uc73c\ub85c DBWR(Database Writer Process) <\/span>\uc5d0 \uc758\ud574\uc11c \uad00\ub9ac\ub41c\ub2e4. <\/span><\/span><\/p>\n

Free
\nBuffer<\/span>\ub294 \uc624\ub77c\ud074 \uc11c\ubc84 \ud504\ub85c\uc138\uc2a4\uc5d0 \ud560\ub2f9\ub418\uc5b4 \uc0ac\uc6a9\ub418\uace0, <\/span>\uc0ac\uc6a9 \ud6c4 Dirty Buffer<\/span>\uac00 \ub41c Buffer<\/span>\ub4e4\uc740 DBWR<\/span>\uc5d0 \uc758\ud574 \ub514\uc2a4\ud06c\uc5d0 \uc4f0\uc5ec\uc9c4 \ud6c4 \ub2e4\uc2dc Free Buffer<\/span>\uac00 \ub418\uc5b4
\n\uc624\ub77c\ud074 \uc11c\ubc84 \ud504\ub85c\uc138\uc2a4\uc5d0 \uc758\ud574 \uc7ac\uc0ac\uc6a9\ub418\ub294 \uc791\uc5c5\uc744 \ubc18\ubcf5\ud558\uac8c \ub41c\ub2e4.<\/span><\/span><\/p>\n


<\/span><\/span><\/b><\/p>\n

Free Buffer <\/span>\ub97c \ucc3e\ub294 \uacfc\uc815<\/span><\/b><\/p>\n<\/p>\n

1.<\/span><\/b> <\/span>\uc624\ub77c\ud074 \ud504\ub85c\uc138\uc2a4\uac00 LRU List<\/span>\uc5d0 Lock<\/span>\uc744 \uac78\uace0 LRU<\/span>\uc758 \ub05d\ubd80\ubd84\ubd80\ud130
\nFree Buffer <\/span>\ube14\ub85d\uc744 \ucc3e\uae30 \uc2dc\uc791\ud55c\ub2e4. <\/span>\uc774\ub97c \ucc3e\ub294 \uc911\uc5d0 Dirty Buffer<\/span>\ub97c \ub9cc\ub098\uba74, <\/span>\uc774 Dirty Buffer<\/span>\ub97c LRUW List<\/span>\uc5d0 \uc62e\uae34\ub2e4. <\/p>\n

2.<\/b> LRU List<\/span>\ub97c \ucc3e\uc744 \ub54c\ub3c4 \ub05d\uae4c\uc9c0 \ub2e4 \ucc3e\ub294 \uac83\uc740 \uc544\ub2c8\uace0, Kernel<\/span>\uc5d0\uc11c
\n\uc9c0\uc815\ud558\ub294 \uc5b4\ub290 \ud2b9\uc815 \uac12\ub9cc\ud07c Depth<\/span>\ub97c \uc815\ud558\uc5ec \uc2a4\uce94\ud558\uba70, <\/span>\uc774
\n\uac1c\uc218(foreground scan depth) <\/span>\ub0b4\uc5d0\uc11c \ucc3e\uc9c0 \ubabb\ud558\uba74 \uc624\ub77c\ud074 \ud504\ub85c\uc138\uc2a4\ub294 \ub354 \uc774\uc0c1 LRU List <\/span>\ub294 \uc77d\uc9c0 \uc54a\uace0 , DBWR<\/span>\uc5d0\uac8c Dirty Buffer<\/span>\ub97c \ubaa8\uc73c\ub3c4\ub85d \ud558\ub294 \uba54\uc2dc\uc9c0\ub97c \ubcf4\ub0b4\ub294 \uc791\uc5c5\uc774 \uc218\ud589\ub418\uace0 LRU
\nLatch<\/span>\ub294 \ud574\uc81c\ub41c\ub2e4.<\/p>\n

3.<\/b> <\/span>\uba54\uc2dc\uc9c0\ub97c \ubc1b\uc740 DBWR<\/span>\ub294 LRU
\nLatch Lock<\/span>\uc744 \uac78\uace0, LRU <\/span>\uaf2c\ub9ac \ubd80\ubd84\uc5d0\uc11c
\nDBWR Scan Depth<\/span>\ub9cc\ud07c\uc758 \ub514\uc2a4\ud06c\uc5d0 \uc4f0\uc5ec\uc838\uc57c \ud560 Dirty Buffer<\/span>\ub4e4\uc744 \ubaa8\uc73c\ub294 Large Batch Write<\/span>\ub97c \uc218\ud589\ud55c\ub2e4.<\/p>\n

4. <\/b>LRUW<\/span>\uc5d0 \ubaa8\uc778 Dirty Buffer<\/span>\ub294 DBWR<\/span>\uc5d0 \uc758\ud574 \ub514\uc2a4\ud06c\ub85c \uc4f0\uc5ec\uc9c0\uace0 \ub098\uba74 \uc774 Buffer<\/span>\ub294 Free Buffer<\/span>\ub85c \ub418\uc5b4 \ub2e4\uc2dc \uc0ac\uc6a9\ub420 \uc218 \uc788\ub3c4\ub85d LRU<\/span>\uc758 \ub05d\ubd80\ubd84\uc5d0
\n\uc704\uce58\ud558\uac8c \ub41c\ub2e4.<\/span><\/span><\/span><\/p>\n


<\/span><\/span><\/p>\n

<\/span>
<\/span><\/p>\n

<\/p>\n

<\/span><\/span>* <\/span>\uc624\ub77c\ud074 Database Buffer Cache <\/span>\uc548\uc758 \ube14\ub85d\ub4e4\uc740
\n\ubaa8\ub450\uac00 LRU List \/ LRUW List <\/span>\ub458\uc911 \ud558\ub098\uc5d0 \uc18d\ud558\uac8c \ub41c\ub2e4.<\/span><\/span><\/p>\n

<\/span><\/span><\/p>\n


<\/span><\/span><\/p>\n

\uc6a9\uc5b4 \uc124\uba85<\/b><\/span><\/font><\/p>\n

 – LRU(Least Recently Used) List<\/b> : <\/span>\ucd5c\uadfc\uc5d0 \uc77d\ud600\uc9c4 Datafile Block <\/span>\uc744 Buffer Cache<\/span>\uc5d0  <\/span>\ubcf4\uad00\ud558\uace0, <\/span>\uc0c8\ub85c\uc6b4 Block <\/span>\uc774 \ud30c\uc77c\uc5d0\uc11c \uc77d\ud600\uc9c8 \ud544\uc694\uac00 \uc788\uc73c\uba74 \uc0ac\uc6a9\ud55c\uc9c0 \uac00\uc7a5 \uc624\ub798\ub41c \ubc84\ud37c\ub4e4\ubd80\ud130 \uba54\ubaa8\ub9ac\uc5d0\uc11c \uc5c6\uc5b4\uc9c0\ub3c4\ub85d \uad00\ub9ac\ud558\uae30 \uc704\ud55c
\nBuffer Cache <\/span>\ub0b4\uc758 Block List<\/span>\ub97c \uc720\uc9c0\uad00\ub9ac\ud568.<\/span><\/span><\/p>\n

 – Dirty List(LRUW List)<\/b> : Buffer Cache <\/span>\uc548\uc758 Block<\/span>\ub4e4\uc740 \uadf8 \uc0c1\ud0dc\uc5d0 \ub530\ub77c\uc11c \ub2e4\uc74c \uc138\uac00\uc9c0 \uc0c1\ud0dc\ub97c
\n\uac00\uc9c4\ub2e4.<\/span><\/span><\/p>\n

   1. Free Buffer<\/b>   : <\/span>Dirty Buffer<\/span>\uac00 \ub514\uc2a4\ud06c\uc5d0 \uc4f0\uc5ec\uc9c4 \ud6c4 Free<\/span>\ub85c \ub9c8\ud06c\ub418\uc5b4 \uc0ac\uc6a9\ud560 \uc218 \uc788\ub294
\n\uc0c1\ud0dc\ub85c \ub418\uc5c8\uac70\ub098 \ucc98\uc74c Load <\/span>\ub41c \uc774\ud6c4 \ub0b4\uc6a9\uc774 \ubcc0\uacbd\ub418\uc9c0 \uc54a\uc544 \uc0ac\uc6a9 \uac00\ub2a5\ud55c Buffer<\/span><\/span><\/span><\/p>\n

   2. Dirty Buffer<\/b>  : Datafile <\/span>\uc5d0\uc11c Buffer Cache <\/span>\ub85c \uc77d\ud600\uc9c4 \uc774\ud6c4 \ube14\ub85d\uc5d0 \ubcc0\uacbd\uc0ac\ud56d\uc774 \ubc1c\uc0dd\ud588\ub294\ub370, <\/span>\ub2e4\uc2dc Datafile <\/span>\uc5d0
\nWrite <\/span>\ub418\uc9c0 \uc54a\uc740 \uc0c1\ud0dc\uc758 \ubc84\ud37c<\/span><\/span><\/p>\n

   3. Pinned Buffer<\/b> : <\/span>\uc11c\ubc84\ud504\ub85c\uc138\uc2a4\uc5d0 \uc758\ud574 \uc0ac\uc6a9\ub41c \uc0c1\ud0dc\uc758 \ubc84\ud37c<\/span><\/span><\/p>\n<\/p>\n

Dirty Buffer<\/span>\ub4e4\uc740 \uc624\ub77c\ud074 \ud504\ub85c\uc138\uc2a4\ub4e4\uc774 \uc790\uc2e0\uc774 \uc0ac\uc6a9\ud560 Free Buffer<\/span>\ub97c \ucc3e\uae30 \uc704\ud574 LRU List<\/span>\ub97c \uaf2c\ub9ac \ubd80\ubd84(LRU)<\/span>\ubd80\ud130 \ucc3e\uc544\ub098\uac00\ub2e4 Dirty Buffer<\/span>\ub97c \ub9cc\ub098\uba74 \uc774\ub97c LRUW List<\/span>\uc5d0 \uc62e\uaca8\ub193\uc740
\n\uac83\ub4e4\ub85c, <\/span>\uc774 Buffer<\/span>\ub4e4\uc740 \uacb0\uad6d DBWR(DB Writer)<\/span>\uc5d0 \uc758\ud574 \ub514\uc2a4\ud06c\uc5d0 \uc4f0\uc5ec\uc9c0\uace0 \ub2e4\uc2dc Free<\/span>\ub85c
\n\ub9c8\ud06c\ub418\uc5b4 LRU List<\/span>\ub85c \uac00\uac8c \ub41c\ub2e4.<\/span><\/span><\/span><\/p>\n


<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

– \uc624\ub77c\ud074 \ud504\ub85c\uc138\uc2a4\uac00 Free Buffer \ub97c \ucc3e\ub294 \uacfc\uc815 – Database Buffer Cache \ucd5c\uadfc\uc5d0 \uc0ac\uc6a9\ub41c \ub370\uc774\ud0c0\ubca0\uc774\uc2a4\uc758 \ub370\uc774\ud0c0 \ube14\ub85d\uc744 \uc800\uc7a5\ud558\uace0 \uc788\ub294 Database Buffer \uc601\uc5ed\uc73c\ub85c DBWR(Database Writer Process) \uc5d0 \uc758\ud574\uc11c \uad00\ub9ac\ub41c\ub2e4.  Free Buffer\ub294 \uc624\ub77c\ud074 \uc11c\ubc84 \ud504\ub85c\uc138\uc2a4\uc5d0 \ud560\ub2f9\ub418\uc5b4 \uc0ac\uc6a9\ub418\uace0, \uc0ac\uc6a9 \ud6c4 Dirty Buffer\uac00 \ub41c Buffer\ub4e4\uc740 DBWR\uc5d0 \uc758\ud574 \ub514\uc2a4\ud06c\uc5d0 \uc4f0\uc5ec\uc9c4 \ud6c4 \ub2e4\uc2dc Free Buffer\uac00 \ub418\uc5b4 \uc624\ub77c\ud074 \uc11c\ubc84 \ud504\ub85c\uc138\uc2a4\uc5d0 \uc758\ud574 \uc7ac\uc0ac\uc6a9\ub418\ub294 […]<\/p>\n","protected":false},"author":1,"featured_media":437,"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":[204],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/haisins.synology.me\/wordpress\/wp-content\/uploads\/1\/cfile5.uf.2163F65055E7D1AC2321D6.jpg?fit=430%2C440","amp_enabled":true,"_links":{"self":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/436"}],"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=436"}],"version-history":[{"count":0,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/436\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/media\/437"}],"wp:attachment":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=436"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}