{"id":461,"date":"2015-09-07T04:58:59","date_gmt":"2015-09-07T04:58:59","guid":{"rendered":"http:\/\/haisins.epac.to\/wordpress\/?p=461"},"modified":"2015-09-07T04:58:59","modified_gmt":"2015-09-07T04:58:59","slug":"sql-%ec%84%b1%eb%8a%a5%ec%9d%84-%ec%9c%84%ed%95%9c-%ea%b8%b0%ec%b4%88%ec%a0%81%ec%9d%b8-sql-%ec%9e%91%ec%84%b1-25%ea%b0%80%ec%a7%80-%ea%b7%9c%ec%b9%99","status":"publish","type":"post","link":"http:\/\/haisins.synology.me\/wordpress\/?p=461","title":{"rendered":"SQL \uc131\ub2a5\uc744 \uc704\ud55c \uae30\ucd08\uc801\uc778 SQL \uc791\uc131 25\uac00\uc9c0 \uaddc\uce59"},"content":{"rendered":"<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>1.\ub370\uc774\ud130\uc640 \ube44\uc988\ub2c8\uc2a4 \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc744 \uc798 \uc54c\uc544\uc57c \ud55c\ub2e4.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub3d9\uc77c\ud55c \uc815\ubcf4\ub294 \ub2e4\ub978 \ube44\uc988\ub2c8\uc2a4 \ub370\uc774\ud130 \uc6d0\ucc9c\uc73c\ub85c\ubd80\ud130 \uac80\uc0c9\ub420 \uc218 \uc788\ub2e4. \uc774\ub7ec\ud55c \uc6d0\ucc9c\uc5d0 \uc775\uc219\ud574\uc57c \ud55c\ub2e4. \ub2f9\uc2e0\uc740 \ub2f9\uc2e0\uc758 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc548\uc758 \ub370\uc774\ud130\uc758 \ud06c\uae30\uc640 \ubd84\ud3ec\ub97c \ubc18\ub4dc\uc2dc \uc54c\uc544\uc57c \ud55c\ub2e4. \ub610\ud55c SQL\uc744 \uc791\uc131\ud558\uae30 \uc804\uc5d0 \ube44\uc988\ub2c8\uc2a4 \uac1c\uccb4 \uc548\uc758 \uad00\uacc4\uc640 \uac19\uc740 \ub370\uc774\ud130 \ubaa8\ub378\uc744 \uc804\uccb4\uc801\uc73c\ub85c \uc774\ud574\ud574\uc57c \ud55c\ub2e4. \uc774\ub7ec\ud55c \uc774\ud574\ub294 \ub2f9\uc2e0\uc774 \uc5ec\ub7ec \ud14c\uc774\ube14\uc5d0\uc11c \uc815\ubcf4\ub97c \uac80\uc0c9\ud558\ub294\ub370 \uc788\uc5b4\uc11c \ubcf4\ub2e4 \uc88b\uc740 \ucffc\ub9ac\ub97c \uc791\uc131\ud560 \uc218 \uc788\ub2e4. DESIGNER\/2000 \uacfc \uac19\uc740 CASE TOOLS\uc740 \ub2e4\ub978 \ube44\uc988\ub2c8\uc2a4\uc640 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uac1d\uccb4\uc0ac\uc774\uc758 \uad00\uacc4\ub97c \ubb38\uc11c\ud654 \ud558\ub294\ub370 \uc88b\uc740 \uc5ed\ud560\uc744 \ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>2.\uc2e4\uc81c \ub370\uc774\ud130\ub97c \uac00\uc9c0\uace0 \ub2f9\uc2e0\uc758 \ucffc\ub9ac\ub97c \uac80\uc0ac\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub300\ubd80\ubd84\uc758 \uc870\uc9c1\uc740 \uac1c\ubc1c, \uac80\uc0ac, \uc81c\ud488\uc758 3\uac00\uc9c0 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ud658\uacbd\uc744 \uac00\uc9c4\ub2e4. \ud504\ub85c\uadf8\ub798\uba38\ub294 \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc744 \ub9cc\ub4e4\uace0 \uac80\uc0ac\ud558\ub294\ub370 \uac1c\ubc1c \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ud658\uacbd\uc744 \uc0ac\uc6a9\ud558\ub294\ub370, \uc774 \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc774 \uc81c\ud488 \ud658\uacbd\uc73c\ub85c \uc804\ud658\ub418\uae30 \uc804\uc5d0 \ud504\ub85c\uadf8\ub798\uba38\uc640 \uc0ac\uc6a9\uc790\uc5d0 \uc758\ud574 \uac80\uc0ac \ud658\uacbd\ud558\uc5d0\uc11c \ubcf4\ub2e4 \uc5c4\uaca9\ud558\uac8c \uac80\ud1a0\ub418\uc5b4\uc57c \ud55c\ub2e4. SQL\uc774 \uac80\uc0ac \ud658\uacbd\ud558\uc5d0\uc11c \ud14c\uc2a4\ud2b8\ub420 \ub54c, \uac80\uc0ac \ub370\uc774\ud130\ubca0\uc774\uc2a4\uac00 \uac00\uc9c0\uace0 \uc788\ub294 \ub370\uc774\ud130\ub294 \uc81c\ud488 \ub370\uc774\ud130\ubca0\uc774\uc2a4\ub97c \ubc18\uc601\ud574\uc57c \ud55c\ub2e4. \ube44\uc2e4\uc81c\uc801\uc778 \ub370\uc774\ud130\ub97c \uac00\uc9c0\uace0 \ud14c\uc2a4\ud2b8\ub41c SQL\ubb38\uc740 \uc81c\ud488 \uc548\uc5d0\uc11c\ub294 \ub2e4\ub974\uac8c \uc791\ub3d9\ud560 \uc218 \uc788\ub2e4. \uc5c4\uaca9\ud55c \ud14c\uc2a4\ud2b8\ub97c \ubcf4\uc7a5\ud558\uae30 \uc704\ud574\uc11c\ub294, \uac80\uc0ac \ud658\uacbd\ud558\uc5d0\uc11c\uc758 \ub370\uc774\ud130 \ubd84\ud3ec\ub294 \ubc18\ub4dc\uc2dc \uc81c\ud488 \ud658\uacbd\uc5d0\uc11c\uc758 \ubd84\ud3ec\uc640 \ubc00\uc811\ud558\uac8c \ub2ee\uc544\uc57c \ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>3.\ub3d9\uc77c\ud55c SQL\uc744 \uc0ac\uc6a9\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uac00\ub2a5\ud55c\ud55c BIND VARIABLE, STORED PROCEDURE, PACKAGE\uc758 \uc774\uc810\uc744 \ud65c\uc6a9\ud558\ub77c. IDENTICAL SQL\ubb38\uc758 \uc774\uc810\uc740 PARSING\uc774 \ubd88\ud544\uc694\ud558\uae30\uc5d0 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc11c\ubc84\uc548\uc5d0\uc11c \uba54\ubaa8\ub9ac \uc0ac\uc6a9\uc758 \ucd95\uc18c\uc640 \ube60\ub978 \uc218\ud589\uc744 \ud3ec\ud568\ud55c\ub2e4. \uc608\ub85c\uc11c \uc544\ub798\uc758 SQL \ubb38\uc740 IDENTICAL\ud558\uc9c0 \uc54a\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * FROM EMPLOYEE WHERE EMPID = 10;\n<\/p>\n<p>SELECT * FROM EMPLOYEE WHERE EMPID = 10;\n<\/p>\n<p>SELECT * FROM EMPLOYEE WHERE EMPID = 20;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uadf8\ub7ec\ub098 I_EMPID\ub77c\uace0 \uc774\ub984 \uc8fc\uc5b4\uc9c4 BIND VARIABLE\uc744 \uc0ac\uc6a9\ud558\uba74 SQL \ubb38\uc740 \uc774\ub807\uac8c \ub41c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * FROM EMPLOYEE WHERE EMPID = :I_EMPID;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>4.\uc8fc\uc758 \uae4a\uac8c \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ud14c\uc774\ube14\uc0c1\uc5d0 \ubaa8\ub4e0 \ud544\uc694\ud55c \uc778\ub371\uc2a4\ub294 \uc0dd\uc131\ub418\uc5b4\uc57c \ud55c\ub2e4. \ud558\uc9c0\ub9cc \ub108\ubb34 \ub9ce\uc740 \uc778\ub371\uc2a4\ub294 \uc131\ub2a5\uc744 \ub5a8\uc5b4\ub728\ub9b4 \uc218 \uc788\ub2e4. \uadf8\ub7ec\uba74 \uc5b4\ub5bb\uac8c \uc778\ub371\uc2a4\ub97c \ub9cc\ub4e4 \uce7c\ub7fc\uc744 \uc120\ud0dd\ud574\uc57c \ud558\ub294 \uac00?\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>*\ucd5c\uc885 \uc0ac\uc6a9\uc790\uc5d0 \uc758\ud574 \uc0ac\uc6a9\ub418\ub294 \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158 SQL\uacfc \ucffc\ub9ac\uc758 WHERE \uc808\uc5d0\uc11c \ube48\ubc88 \ud558\uac8c \uc0ac\uc6a9\ub418\ub294 \uce7c\ub7fc\uc5d0 \uc778\ub371\uc2a4\ub97c \ub9cc\ub4e4\uc5b4\uc57c \ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>*SQL \ubb38\uc5d0\uc11c \uc790\uc8fc \ud14c\uc774\ube14\uc744 JOIN\ud558\ub294\ub370 \uc0ac\uc6a9\ub418\ub294 \uce7c\ub7fc\uc740 \uc778\ub371\uc2a4\ub418\uc5b4\uc57c \ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>*\uac19\uc740 \uac12\uc744 \uac00\uc9c0\ub294 ROW\uac00 \uc801\uc740 \ube44\uc728\uc744 \uac00\uc9c0\ub294 \uce7c\ub7fc\uc5d0 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\ub77c.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>*\ucffc\ub9ac\uc758 WHERE \uc808\uc5d0\uc11c \uc624\uc9c1 \ud568\uc218\uc640 OPERATOR\ub85c \uc0ac\uc6a9\ub418\ub294 \uce7c\ub7fc\uc5d0\ub294 \uc778\ub371\uc2a4\ub97c \ub9cc\ub4e4 \uba74 \uc548\ub41c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>*\uc790\uc8fc \ubcc0\uacbd\ub418\uac70\ub098 \uc778\ub371\uc2a4\ub97c \ub9cc\ub4e4\ub54c \uc5bb\ub294 \ud6a8\uc728\uc131\ubcf4\ub2e4 \uc0bd\uc785, \uac31\uc2e0, \uc0ad\uc81c\ub85c \uc778\ud574 \uc783\ub294 \ud6a8\uc728\uc131\uc774 \ub354 \ud070 \uce7c\ub7fc\uc5d0\ub294 \uc778\ub371\uc2a4\ub97c \ub9cc\ub4e4\uba74 \uc548\ub41c\ub2e4. \uc774\ub7ec\ud55c OPERATION\uc740 \uc778\ub371\uc2a4\ub97c \uc720\uc9c0\ud558\uae30 \uc704\ud55c \ud544\uc694 \ub54c\ubb38\uc5d0 \ub290\ub824\uc9c4\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>*UNIQUE \uc778\ub371\uc2a4\ub294 \ub354 \ub098\uc740 \uc120\ud0dd\uc131 \ub54c\ubb38\uc5d0 NONUNIQUE \uc778\ub371\uc2a4\ubcf4\ub2e4 \uc88b\ub2e4. PRIMARY KEY \uce7c\ub7fc\uc5d0 UNIQUE \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud55c\ub2e4. \uadf8\ub9ac\uace0 FOREIGN KEY \uce7c\ub7fc\uacfc WHERE \uc808 \uc5d0\uc11c \uc790\uc8fc \uc0ac\uc6a9\ub418\ub294 \uce7c\ub7fc\uc5d0\ub294 NONUNIQUE \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>5.\uac00\uc6a9\ud55c \uc778\ub371\uc2a4 PATH\ub97c \ub9cc\ub4e4\uc5b4\ub77c<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uae30 \uc704\ud574\uc11c\ub294 \uae30\uc220\ud55c SQL\ubb38\uc744 \uc774\uc6a9\ud560 \uc218 \uc788\ub294 \uc2dd\uc73c\ub85c SQL\uc744 \uc791\uc131\ud558\ub77c. OPTIMIZER\ub294 \uc778\ub371\uc2a4\uac00 \uc874\uc7ac\ud558\uae30 \ub54c\ubb38\uc5d0 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\ub294 ACESS PATH \ub97c \uc0ac\uc6a9\ud560 \uc218 \uc5c6\ub2e4. \ub530\ub77c\uc11c ACCESS PATH\ub294 \ubc18\ub4dc\uc2dc SQL\uc774 \uc0ac\uc6a9\ud560 \uc218 \uc788\uac8c \ub9cc\ub4e4\uc5b4 \uc838\uc57c \ud55c\ub2e4. SQL HINT\ub97c \uc0ac\uc6a9\ud558\ub294 \uac83\uc740 \uc778\ub371\uc2a4 \uc0ac\uc6a9\uc744 \ubcf4\uc99d\ud574\uc8fc\ub294 \ubc29\ubc95\uc911 \ud558\ub098\uc774\ub2e4. \ud2b9\uc815 ACCESS PATH\ub97c \uc120\ud0dd\ud558\uae30 \uc704\ud55c \ub2e4\uc74c\uc758 \ud78c\ud2b8\ub97c \ucc38\uace0 \ud558\ub77c\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>6.\uac00\ub2a5\ud558\uba74 EXPLAIN\uacfc TKPROF\ub97c \uc0ac\uc6a9\ud558\ub77c<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub9cc\uc57d SQL\ubb38\uc774 \uc798 \ub2e4\ub4ec\uc5b4\uc9c0\uc9c0 \uc54a\uc558\ub2e4\uba74 \ube44\ub85d \uc624\ub77c\ud074 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uac00 \uc798 \uc9dc\uc5ec\uc838 \uc788\uc5b4\ub3c4 \ud6a8\uc728\uc131\uc774 \ub5a8\uc5b4\uc9c8 \uac83\uc774\ub2e4. \uc774\ub7f4 \uacbd\uc6b0 EXPLAIN TKPROF\uc5d0 \ub2a5\uc219\ud574\uc838\uc57c \ud55c\ub2e4. EXPALIN PLAN\uc740 SQL\uc774 \uc0ac\uc6a9\ud558\ub294 ACCESS PATH\ub97c \ubc1c\uacac\ud560 \uc218 \uc788\uac8c \ud574\uc8fc\uace0 TKPROF\ub294 \uc2e4\uc81c PERFORMANEC\uc758 \ud1b5\uacc4\uce58\ub97c \ubcf4\uc5ec\uc900\ub2e4. \uc774 TOOL\uc740 \uc624\ub77c\ud074 \uc11c\ubc84 \uc18c\ud504\ud2b8\uc6e8\uc5b4\uc5d0 \ud3ec\ud568\ub418\uc5b4 \uc788\uace0 SQL\uc758 \uc131\ub2a5\uc744 \ud5a5\uc0c1\uc2dc\ucf1c \uc900\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>7.OPTIMIZER\ub97c \uc774\ud574\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>SQL\uc740 RULE-BASED\ub098 COST-BASED\uc911 \ud558\ub098\ub97c \uc774\uc6a9\ud574\uc11c \uae30\ub3d9\ub41c\ub2e4.\uae30\uc874\uc758 \uc18c\ud504\ud2b8\uc6e8\uc5b4\ub294 RULE BASED \ubc29\uc2dd\uc744 \ucc44\ud0dd\ud558\uace0 \uc788\ub2e4. \uadf8\ub9ac\uace0 \ub9ce\uc740 \uc624\ub77c\ud074 \uc18c\ud504\ud2b8\uc6e8\uc5b4\uac00 \uc774\ub7ec\ud55c \ubc29\uc2dd\uc744 \uc624\ub7ab\ub3d9\uc548 \uc0ac\uc6a9\ud574 \uc654\ub2e4. \uadf8\ub7ec\ub098 \uc0c8\ub85c \ucd9c\uc2dc\ub41c \uc18c\ud504\ud2b8\uc6e8\uc5b4\uc5d0 \ub300\ud574\uc11c\ub294 COST BASED \ubc29\uc2dd\uc758 OPTIMIZER\ub97c \uace0\ub824\ud574\uc57c \ud55c\ub2e4. \uc624\ub77c\ud074\uc740 \uc0c8\ub85c \ucd9c\uc2dc\ub418\ub294 \ud504\ub85c\uadf8\ub7a8\uc744 COST BASED\ubc29\uc2dd\uc73c\ub85c \uc5c5\uadf8\ub808\uc774\ub4dc \uc2dc\ucf1c\uc654\uc73c\uba70 \uc774\ub7ec\ud55c \ubc29\uc2dd\uc740 \uc2dc\uc2a4\ud15c\uc744 \ud6e8\uc52c \ub354 \uc548\uc815\uc801\uc73c\ub85c \ub9cc\ub4e4\uc5c8\ub2e4. \ub9cc\uc57d COST BASED\ubc29\uc2dd\uc758 OPTIMIZER\ub97c \uc0ac\uc6a9\ud55c\ub2e4\uba74 \ubc18\ub4dc\uc2dc ANALYZE \uc2a4\ud0a4\ub9c8\ub97c \uc815\uae30\uc801\uc73c\ub85c \uc0ac\uc6a9\ud574\uc57c \ud55c\ub2e4. ANALYZE\uc2a4\ud0a4\ub9c8\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ud1b5\uacc4\ub97c \ub370\uc774\ud130 \uc0ac\uc804 \ud14c\uc774\ube14\uc5d0 \uae30\ub85d\ud558\ub294 \uc5ed \ud560\uc744 \uc218\ud589\ud558\uba70 \uadf8\ub807\uac8c \ub418\uba74 COST BASED OPTIMIZER\uac00 \uadf8\uac83\uc744 \uc0ac\uc6a9\ud558\uac8c \ub41c\ub2e4. SQL\uc740 COST BASED OPTIMIZER\ub97c \uc0ac\uc6a9\ud560 \ub54c\ub9cc \uc798 \uc870\uc815\ub420 \uc218 \uc788\ub2e4. \ub9cc\uc57d RULE BASED\uc5d0\uc11c COST BASED\ub85c \ubc14\uafb8\uace0 \uc2f6\ub2e4\uba74 \ub370\uc774\ud130\ubca0\uc774\uc2a4\ub97c \uc0ac\uc6a9\ud558\ub294 \ubaa8 \ub4e0 \uc18c\ud504\ud2b8\uc6e8\uc5b4\uc758 \ubaa8\ub4e0 SQL\ubb38\uc758 \uc131\ub2a5\uc744 \ud3c9\uac00\ud574 \ubcf4\uc544\uc57c \ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>8.\uc9c0\uc5fd\uc801\uc73c\ub85c \ub3d9\uc791\ud558\ub354\ub77c\ub3c4 \uc804\uc5ed\uc801\uc73c\ub85c \uc0dd\uac01\ud558\ub77c<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ud56d\uc0c1 \uc8fc\uc758\ud560 \uac83\uc740 \ud558\ub098\uc758 SQL\ubb38\uc744 \uc870\uc815\ud558\uae30 \uc704\ud574 \uc0dd\uae34 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc548\uc758 \ubcc0\ud654 \ub294 \ub2e4\ub978 \uc751\uc6a9\ud504\ub85c\uadf8\ub7a8\uc774\ub098 \ub2e4\ub978 \uc0ac\uc6a9\uc790\uac00 \uc774\uc6a9\ud558\ub294 \ub2e4\ub978 \uba85\ub839\ubb38\uc5d0 \uc601\ud5a5\uc744 \ubbf8\uce5c\ub2e4\ub294 \uc0ac\uc2e4\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>9.WHERE\uc808\uc740 \ub9e4\uc6b0 \uc911\uc694\ud558\ub2e4.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ube44\ub85d \uc778\ub371\uc2a4\uac00 \uac00\uc6a9\ud558\ub2e4\uace0 \ud574\ub3c4 \ub2e4\uc74c\uc758 WHERE \uc808\uc740 \uadf8 \uc778\ub371\uc2a4 ACCESS PATH \ub97c \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294\ub2e4.(\uc989 COL1 \uacfc COL2\ub294 \uac19\uc740 \ud14c\uc774\ube14\uc5d0 \uc788\uc73c\uba70 \uc778\ub371\uc2a4\ub294 COL1\uc5d0 \ub9cc\ub4e4\uc5b4\uc9c4\ub2e4.)\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>COL1 &gt; COL2\n<\/p>\n<p>COL1 &lt; COL2\n<\/p>\n<p>COL1 &gt; = COL2\n<\/p>\n<p>COL1 &lt;= COL2\n<\/p>\n<p>COL1 IS NULL\n<\/p>\n<p>COL1 IS NOT NULL.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc778\ub371\uc2a4\ub294 NULL\uac12\uc744 \uac16\ub294 \uce7c\ub7fc\uc5d0\ub294 ROWID\ub97c \uc800\uc7a5\ud558\uc9c0 \uc54a\ub294\ub2e4. \ub530\ub77c\uc11c NULL\uac12 \uc744 \uac16\ub294 ROW\ub97c \uac80\uc0c9\ud560 \ub54c\ub294 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uc9c0 \ubabb\ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>COL1 NOT IN (VALUE1, VALUE2 )\n<\/p>\n<p>COL1 != EXPRESSION\n<\/p>\n<p>COL1 LIKE &#8221;%PATTERN&#8221;.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc774\ub7f4 \uacbd\uc6b0 THE LEADING EDGE OF THE INDEX(?) \ub294 \uc791\ub3d9\ub418\uc9c0 \uc54a\uace0 \uc778\ub371\uc2a4\uac00 \uc0ac\uc6a9\ub418\uc9c0 \ubabb\ud558\uac8c \ud55c\ub2e4. \ud55c\ud3b8 COL1 LIKE &#8221;PATTERN %&#8221;\uc774\ub098 COL1 LIKE &#8221;PATTERN %PATTERN%&#8221; \ub294 \ud55c\uc815\ub41c \uc778\ub371\uc2a4 \uc2a4\uce94\uc744 \uc218\ud589\ud558\uae30 \ub54c\ubb38\uc5d0 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>NOT EXISTS SUBQUERY\n<\/p>\n<p>EXPRESSION1 = EXPRESSION2.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc778\ub371\uc2a4\ub41c \uceec\ub7fc\uc744 \ud3ec\ud568\ud558\ub294 \ud45c\ud604(EXPRESSION), \ud568\uc218, \uacc4\uc0b0(CALCULATIONS)\uc740 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uc9c0 \ubabb\ud55c\ub2e4. \ub2e4\uc74c\uc758 \uc608\uc5d0\uc11c \ubcf4\uba74 UPPER SQL \ud568\uc218\ub97c \uc0ac\uc6a9\ud558\uba74 \uc778\ub371\uc2a4 \uc2a4\uce94\uc744 \uc0ac\uc6a9\ud560 \uc218 \uc5c6\uace0 FULL TABLE SCAN\uc73c\ub85c \ub05d\ub098\uace0 \ub9cc\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT DEPT_NAME\n<\/p>\n<p>FROM DEPARTMENT\n<\/p>\n<p>WHERE UPPER(DEPT_NAME) LIKE &#8221;SALES%&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>10.\ub808\ucf54\ub4dc \ud544\ud130\ub9c1\uc744 \uc704\ud574\uc11c\ub294 HAVING\ubcf4\ub2e4\ub294 WHERE\ub97c \uc0ac\uc6a9\ud558\ub77c<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc778\ub371\uc2a4\uac00 \uac78\ub824\uc788\ub294 \uce7c\ub7fc\uc5d0\ub294 GROUP BY\uc640 \uac19\uc774 HAVING\uc808\uc744 \uc0ac\uc6a9\ud558\uc9c0 \ub9c8\ub77c. \uc774 \uacbd\uc6b0 \uc778\ub371\uc2a4\ub294 \uc0ac\uc6a9\ub418\uc9c0 \uc54a\ub294\ub2e4. \ub610\ud55c WHERE\uc808\ub85c \ub41c ROW\ub97c \uc0ac\uc6a9\ud558\uc9c0 \ub9c8\ub77c. \ub9cc\uc57d EMP\ud14c\uc774\ube14\uc774 DEPTID\uceec\ub7fc\uc5d0 \uc778\ub371\uc2a4\ub97c \uac00\uc9c0\uace0 \uc788\ub2e4\uba74 \ub2e4\uc74c \uc9c8\uc758\ub294 HAVING \uc808\uc744 \uc774\uc6a9\ud558\uc9c0 \ubabb\ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT DEPTID,\n<\/p>\n<p>SUM(SALARY)\n<\/p>\n<p>FROM EMP\n<\/p>\n<p>GROUP BY DEPTID\n<\/p>\n<p>HAVING DEPTID = 100;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uadf8\ub7ec\ub098 \uac19\uc740 \uc9c8\uc758\uac00 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uae30 \uc704\ud574 \ub2e4\uc2dc \uc50c\uc5ec\uc9c8 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT DEPTID,\n<\/p>\n<p>SUM(SALARY)\n<\/p>\n<p>FROM EMP\n<\/p>\n<p>WHERE DEPTID = 100\n<\/p>\n<p>GROUP BY DEPTID;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>11. WHERE \uc808\uc5d0 \uc120\ud589 INDEX \uce7c\ub7fc\uc744 \uba85\uc2dc\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ubcf5\ud569 \uc778\ub371\uc2a4\uc758 \uacbd\uc6b0, \uc120\ud589 \uc778\ub371\uc2a4\uac00 WHERE\uc808\uc5d0 \uba85\uc2dc\ub418\uc5b4 \uc788\ub2e4\uba74 \ucffc\ub9ac\ub294 \uadf8 \uc778\ub371\uc2a4 \ub97c \uc0ac\uc6a9\ud560 \uac83\uc774\ub2e4. \ub2e4\uc74c\uc758 \uc9c8\uc758\ub294 PART_NUM\uacfc PRODUCT_ID \uce7c\ub7fc \uc5d0 \uc788\ub294 PRIMARY KEY CONSTRAINT\uc5d0 \uae30\ucd08\ud55c \ubcf5\ud569 \uc778\ub371\uc2a4\ub97c \uc774\uc6a9\ud560 \uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT *\n<\/p>\n<p>FROM PARTS\n<\/p>\n<p>WHERE PART_NUM = 100;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ubc18\uba74, \ub2e4\uc74c\uc758 \ucffc\ub9ac\ub294 \ubcf5\ud569\uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT *\n<\/p>\n<p>FROM PARTS\n<\/p>\n<p>WHERE PRODUCT_ID = 5555;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uac19\uc740 \uc694\uccad(REQUEST)\uc774 \uc778\ub371\uc2a4\ub97c \uc774\uc6a9\ud558\uae30 \uc704\ud574 \ub2e4\uc2dc \uc50c\uc5b4 \uc9c8 \uc218 \uc788\ub2e4. \ub2e4\uc74c \uc9c8\uc758 \uc758 \uacbd\uc6b0, PART_NUM\uceec\ub7fc\uc740 \ud56d\uc0c1 0 \ubcf4\ub2e4 \ud070 \uac12\uc744 \uac00\uc9c8\uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT *\n<\/p>\n<p>FROM PARTS\n<\/p>\n<p>WHERE PART_NUM &gt; 0\n<\/p>\n<p>AND PRODUCT_ID = 5555;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>12.\uc778\ub371\uc2a4 SCAN\uacfc FULL TABLE SCAN\uc744 \ud3c9\uac00\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ud55c \ud589(ROW)\uc758 15% \uc774\uc0c1\uc744 \uac80\uc0c9\ud558\ub294 \uacbd\uc6b0\uc5d0\ub294 FULL TABLE SCAN\uc774 INDEX ACESS PATH\ubcf4\ub2e4 \ube60\ub974\ub2e4. \uc774\ub7f0 \uacbd\uc6b0, SQL\uc774 FULL TABLE SCAN\uc744 \uc774\uc6a9\ud560 \uc218 \uc788\ub3c4\ub85d \uc5ec\ub7ec\ubd84 \uc2a4\uc2a4\ub85c SQL\uc744 \uc791\uc131\ud558\ub77c. \ub2e4\uc74c\uc758 \uba85\ub839\ubb38\uc740 \ube44\ub85d \uc778\ub371\uc2a4\uac00 SALARY COLUMN\uc5d0 \ub9cc\ub4e4\uc5b4\uc838 \uc788\uc5b4\ub3c4 \uc778\ub371\uc2a4 SCAN\uc744 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\uc744 \uac83\uc774\ub2e4. \uccab \ubc88\uc9f8 SQL \uc5d0\uc11c, FULL HINT\ub97c \uc0ac\uc6a9\ud55c\ub2e4\uba74 \uc624\ub77c\ud074\uc740 FULL TABLE SCAN\uc744 \uc218\ud589\ud560 \uac83\uc774\ub2e4. \uc778\ub371\uc2a4\uc758 \uc0ac\uc6a9\uc774 \ub098\uc05c \uc810\uc774 \ub354 \ub9ce\ub2e4\uba74 \uc544\ub798\uc758 \uae30\uc220\uc744 \uc774\uc6a9\ud574\uc11c \uc778\ub371\uc2a4 \uc218\ud589\uc744 \ub9c9\uc744 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * &#8211;+FULL\n<\/p>\n<p>FROM EMP\n<\/p>\n<p>WHERE SALARY = 50000;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * FROM EMP WHERE SALARY+0 = 50000;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub2e4\uc74c\uc758 \uba85\ub839\ubb38\uc740 \ube44\ub85d \uc778\ub371\uc2a4\uac00 SS# COLUMN\uc5d0 \uc788\uc5b4\ub3c4 \uc778\ub371\uc2a4 SCAN\uc744 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\uc744 \uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * FROM EMP WHERE SS# || &#8221; &#8221; = &#8221;111-22-333&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc624\ub77c\ud074\uc774 \ubd88\ubd84\uba85\ud55c \ub370\uc774\ud130 \ubcc0\ud658\uc744 \uc218\ud589\ud574\uc57c \ud558\ub294 \uacbd\uc6b0 \uc778\ub371\uc2a4\uac00 \ud56d\uc0c1 \uc0ac\uc6a9\ub418\uc9c0 \uc54a\ub294 \uac83\uc740 \uc544\ub2c8\ub2e4. \ub2e4\uc74c\uc758 \uc608\ub97c \ubcf4\uba74, EMP \uce7c\ub7fc\uc5d0 \uc788\ub294 SALARY\ub294 \uc22b\uc790\ud615 \uce7c\ub7fc\uc774\uace0 \ubb38\uc790\ud615\uc774 \uc22b\uc790\uac12\uc73c\ub85c \ubcc0\ud658\ub41c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * FROM EMP WHERE SALARY = &#8221;50000&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ud14c\uc774\ube14\uc758 \ud589\uc774 15%\uc774\uac70\ub098 \uadf8\ubcf4\ub2e4 \uc791\uc744 \uacbd\uc6b0 \uc778\ub371\uc2a4 \uc2a4\uce94\uc740 \ubcf4\ub2e4 \uc798 \uc218\ud589 \ub420 \uac83 \uc774\ub2e4. \uc65c\ub0d0 \ud558\uba74 \uc778\ub371\uc2a4 \uc2a4\uce94\uc740 \uac80\uc0c9\ub41c \ud589(ROW)\ud558\ub098 \ud558\ub098 \ub9c8\ub2e4 \ub2e4\uc911\uc758 \ub17c\ub9ac\uc801\uc778 \uc77d\uae30 \uac80\uc0c9(READ)\uc744 \ud560 \uac83\uc774\uae30 \ub54c\ubb38\uc774\ub2e4. \uadf8\ub7ec\ub098 FULL TABLE SCAN\uc740 \ud558\ub098\uc758 \ub17c\ub9ac\uc801 \uc778 \uc77d\uae30 \uac80\uc0c9 \uc601\uc5ed \uc548\uc758 BLOCK\uc5d0 \uc788\ub294 \ubaa8\ub4e0 \ud589\ub4e4\uc744 \uc77d\uc744 \uc218 \uc788\ub2e4. \uadf8\ub798\uc11c \ud14c\uc774\ube14\uc758 \ub9ce\uc740 \ud589\ub4e4\uc5d0 \uc811\uadfc\ud574\uc57c \ud558\ub294 \uacbd\uc6b0\uc5d0\ub294 FULL TABLE SCAN\uc774 \ub0ab\ub2e4. \uc608\ub85c \ub2e4\uc74c\uc758 \uacbd\uc6b0\ub97c \ubcf4\uc790. \ub9cc\uc57d EMP TABLE\uacfc \uadf8 \ud14c\uc774\ube14\uc758 \ubaa8\ub4e0 \uc778\ub371\uc2a4\uc5d0 \ub300\ud574 ANALYZE\ub77c\ub294 \uba85\ub839\uc5b4\uac00 \uc218\ud589\ub41c\ub2e4\uba74, \uc624\ub77c\ud074\uc740 \ub370\uc774\ud130 \uc0ac\uc804\uc778 USER_TABLES\uc640 USER_INDEXES\uc5d0 \ub2e4\uc74c\uacfc \uac19\uc740 \ud1b5\uacc4\uce58\ub97c \uc0b0\ucd9c\ud574 \ub0b8\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>TABLE STATISTICS:\n<\/p>\n<p>NUM_ROWS = 1000\n<\/p>\n<p>BLOCKS = 100\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>INDEX STATISTICS:\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>BLEVEL = 2\n<\/p>\n<p>AVG_LEAF_BLOCKS_PER_KEY = 1\n<\/p>\n<p>AVG_DATA_BLOCKS_PER_KEY = 1\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc774\ub7ec\ud55c \ud1b5\uacc4\uce58 \uc5d0 \uadfc\uac70\ud574\uc11c, \uc544\ub798\uc5d0 \ubcf4\uc774\ub294 \uac83\uc774 \uac01\uac01\uc758 \ub2e4\ub978 SCAN\uc5d0 \ub300\ud55c \ub17c\ub9ac\uc801\uc778 \uc77d\uae30(READ)-\uc989 ACESS\ub41c BLOCK\uc774 \ub420 \uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>USE OF INDEX TO RETURN ONE ROW = 3\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>(BLEVEL+(AVG_LEAF_BLOCKS_PER_KEY &#8211; 1) +\n<\/p>\n<p>AVG_DATA_PER_KEY\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>FULL TABLE SCAN = 100\n<\/p>\n<p>(BLOCKS)\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>USE OF INDEX TO RETURN ALL ROWS = 3000\n<\/p>\n<p>(NUM_ROWS * BLOCKS ACCESSED TO RETURN ONE ROW USING INDEX)\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>13. \uc778\ub371\uc2a4 \uc2a4\uce94\uc5d0 ORDER BY\ub97c \uc0ac\uc6a9\ud558\ub77c<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc624\ub77c\ud074\uc758 OPTIMIZER\ub294 , \ub9cc\uc57d ORDER BY\ub77c\ub294 \uc808\uc774 \uc778\ub371\uc2a4\ub41c \uce7c\ub7fc\uc5d0 \uc788\ub2e4\uba74 \uc778\ub371\uc2a4 \uc2a4\uce94\uc744 \uc0ac\uc6a9\ud560 \uac83\uc774\ub2e4. \uc544\ub798\uc758 \uc9c8\uc758\ub294 \uc774\ub7ec\ud55c \uc810\uc744 \ubcf4\uc5ec \uc8fc\ub294 \uac83\uc778\ub370 \uc774 \uc9c8\uc758\ub294 \ube44\ub85d \uadf8 \uce7c\ub7fc\uc774 WHERE \uc808\uc5d0 \uba85\uc2dc\ub418\uc5b4 \uc788\uc9c0 \uc54a\ub2e4\uace0 \ud574\ub3c4 EMPID\uceec\ub7fc\uc5d0 \uc788\ub294 \uac00\uc6a9\ud55c \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud560 \uac83\uc774\ub2e4. \uc774 \uc9c8\uc758\ub294 \uc778\ub371\uc2a4\ub85c\ubd80\ud130 \uac01\uac01\uc758 ROWID\ub97c \uac80\uc0c9\ud558\uace0 \uadf8 ROWID\ub97c \uc0ac\uc6a9\ud558\ub294 \ud14c\uc774\ube14\uc5d0 \uc811\uadfc\ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT SALARY FROM EMP ORDER BY EMPID;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub9cc\uc57d \uc774 \uc9c8\uc758\uac00 \uc81c\ub300\ub85c \uc791\ub3d9\ud558\uc9c0 \uc54a\ub294\ub2e4\uba74, \ub2f9\uc2e0\uc740 \uc704\uc5d0\uc11c \uba85\uc2dc\ub418\uc5c8\ub358 FULL HINT \ub97c \uc0ac\uc6a9\ud558\ub294 \uac19\uc740 \uc9c8\uc758\ub97c \ub2e4\uc2dc \uc791\uc131\ud568\uc73c\ub85c\uc368 \ub2e4\ub978 \ub300\uc548\ub4e4\uc744 \uc774\uc6a9\ud574 \ubcfc \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>14. \uc790\uc2e0\uc758 \ub370\uc774\ud130\ub97c \uc54c\uc544\ub77c<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub0b4\uac00 \uc774\ubbf8 \uc124\uba85\ud55c \uac83\ucc98\ub7fc, \ub2f9\uc2e0\uc740 \ub2f9\uc2e0\uc758 \ub370\uc774\ud130\ub97c \uc0c1\uc138\ud558\uac8c \uc54c\uace0 \uc788\uc5b4\uc57c \ud55c\ub2e4. \uc608\ub97c \ub4e4\uc5b4 \ub2f9\uc2e0\uc774 BOXER\ub77c\ub294 \ud14c\uc774\ube14\uc744 \uac00\uc9c0\uace0 \uc788\uace0 \uadf8 \ud14c\uc774\ube14\uc774 \uc720\uc77c\ud558\uc9c0 \uc54a\uc740 \uc778\ub371\uc2a4\ub97c \uac00\uc9c4 SEX\ub77c\ub294 \uceec\ub7fc\uacfc BOXER_NAME\uc774\ub77c\ub294 \ub450 \uac1c\uc758 \ud14c\uc774\ube14\uc744 \uac00\uc9c0\uace0 \uc788 \ub2e4\uace0 \uac00\uc815\ud574 \ubcf4\uc790. \ub9cc\uc57d \uadf8 \ud14c\uc774\ube14\uc5d0 \uac19\uc740 \uc218\uc758 \ub0a8\uc790, \uc5ec\uc790 \ubcf5\uc11c\uac00 \uc788\ub2e4\uba74 \uc624\ub77c\ud074\uc774 FULL TABLE SCAN\uc744 \uc218\ud589\ud558\ub294 \uacbd\uc6b0 \ub2e4\uc74c\uc758 \uc9c8\uc758\uac00 \ud6e8\uc52c \ube60\ub97c \uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT BOXER_NAME FROM BOXER WHERE SEX = &#8221;F&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub2f9\uc2e0\uc740 \ub2e4\uc74c\uacfc \uac19\uc774 \uae30\uc220\ud568\uc73c\ub85c\uc368 \uc9c8\uc758\uac00 FULL TABLE SCAN\uc744 \uc218\ud589\ud558\ub294\uc9c0\ub97c \ud655\uc2e4\ud558\uac8c \ud574 \ub458 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT BOXER_NAME &#8211;+ FULL\n<\/p>\n<p>FROM BOXER\n<\/p>\n<p>WHERE SEX = &#8221;F&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub9cc\uc57d \ud14c\uc774\ube14\uc5d0 980 \uba85\uc758 \ub0a8\uc131 \ubcf5\uc11c \ub370\uc774\ud130\uac00 \uc788\ub2e4\uba74, \uc9c8\uc758\ub294 \uc778\ub371\uc2a4 SCAN\uc73c\ub85c \ub05d\ub098\uae30 \ub54c\ubb38\uc5d0 \uc544\ub798\ud615\uc2dd\uc758 \uc9c8\uc758\uac00 \ub354 \ube60\ub97c \uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT BOXER_NAME &#8211;+ INDEX (BOXER BOXER_SEX)\n<\/p>\n<p>FROM BOXER\n<\/p>\n<p>WHERE SEX = &#8221;F&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc774 \uc608\ub294 \ub370\uc774\ud130\uc758 \ubd84\ud3ec\uc5d0 \ub300\ud574 \uc798 \uc54c\uace0 \uc788\ub294 \uac83\uc774 \uc5bc\ub9c8\ub098 \uc911\uc694\ud55c \uac00\ub97c \uc608\uc2dc\ud574 \uc900\ub2e4. \ub370\uc774\ud130\uac00 \ub9ce\uc544\uc9c0\uace0(GROW) \ub370\uc774\ud130 \ubd84\ud3ec\uac00 \ubcc0\ud654\ud558\ub294 \uac83\ucc98\ub7fc SQL \ub3c4 \ub9e4\uc6b0 \ub2e4\uc591\ud560 \uac83\uc774\ub2e4. \uc624\ub77c\ud074\uc740 OPTIMIZER \uac00 \ud14c\uc774\ube14\uc5d0 \uc788\ub294 \ub370\uc774\ud130\uc758 \ubd84\ud3ec\ub97c \uc798 \uc778\uc2dd\ud558\uace0 \uc801\uc808\ud55c \uc2e4\ud589 \uacc4\ud68d\uc744 \uc120\ud0dd\ud558\ub3c4\ub85d \ud558\uae30 \uc704\ud574 \uc624\ub77c\ud074 7.3 \uc5d0 HISTOGRAMS\ub77c\ub294 \uae30\ub2a5\uc744 \ucd94\uac00\ud588\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>15. KNOW WHEN TO USE LARGE-TABLE SCANS.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc791\uac70\ub098 \ud070 \ud14c\uc774\ube14\uc5d0\uc11c \ud589\ub4e4\uc744 \ucd94\ucd9c\ud560 \ub54c, \uc804\uccb4 \ud14c\uc774\ube14\uc758 \uac80\uc0c9\uc740 \uc778\ud14d\uc2a4\ub97c \uc0ac\uc6a9\ud55c \uac80\uc0c9\ubcf4\ub2e4 \uc131\ub2a5\uc774 \ub354 \uc88b\uc744 \uc218\ub3c4 \uc788\ub2e4. \ub9e4\uc6b0 \ud070 \ud14c\uc774\ube14\uc758 \uc778\ub371\uc2a4 \uac80\uc0c9\uc740 \uc218\ub9ce\uc740 \uc778\ub371\uc2a4\uc640 \ud14c\uc774\ube14 \ube14\ub85d\uc758 \uac80\uc0c9\uc774 \ud544\uc694\ud560\uc218\ub3c4 \uc788\ub2e4. \uc774\ub7ec\ud55c \ube14\ub85d\ub4e4\uc774 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ubc84\ud37c \uce90\uc26c\uc5d0 \uc774\ub3d9\ub418\uba74 \uac00\ub2a5\ud55c\ud55c \uc624\ub798\ub3c4\ub85d \uadf8\uacf3\uc5d0 \uba38\ubb34\ub978\ub2e4. \uadf8\ub798\uc11c \uc774\ub7ec\ud55c \ube14\ub85d\ub4e4\uc774 \ub2e4\ub978 \uc9c8\uc758\ub4f1\uc5d0 \ud544\uc694\ud558\uc9c0 \uc54a\uc744 \uc218\ub3c4 \uc788\uae30 \ub54c\ubb38\uc5d0, \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ubc84\ud37c \ud788\ud2b8 \ube44\uc728\uc774 \uac10\uc18c\ud558\uba70 \ub2e4\uc911 \uc0ac\uc6a9\uc790 \uc2dc\uc2a4\ud15c\uc758 \uc131\ub2a5\ub3c4 \uc800\ud558\ub418\uae30\ub3c4 \ud55c\ub2e4. \uadf8\ub7ec\ub098 \uc804\uccb4 \ud14c\uc774\ube14 \uac80\uc0c9\uc5d0 \uc758\ud574\uc11c \uc77d\ud600\uc9c4 \ube14\ub85d\ub4e4\uc740 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ubc84\ud37c \uce90\uc26c\uc5d0\uc11c \uc77c\ucc0d \uc81c\uac70\uac00 \ub418\ubbc0\ub85c \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ubc84\ud37c \uce90\uc26c \ud788\ud2b8 \ube44\uc728\uc740 \uc601\ud5a5\uc744 \ubc1b\uc9c0 \uc54a\uac8c \ub41c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>16. MINIMIZE TABLE PASSES.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ubcf4\ud1b5, SQL\uc9c8\uc758\uc2dc \ucc38\uc870\ud558\ub294 \ud14c\uc774\ube14\uc758 \uc22b\uc790\ub97c \uc904\uc784\uc73c\ub85c \uc131\ub2a5\uc744 \ud5a5\uc0c1\uc2dc\ud0a8\ub2e4. \ucc38\uc870 \ub418\ub294 \ud14c\uc774\ube14\uc758 \uc22b\uc790\uac00 \uc801\uc744\uc218\ub85d \uc9c8\uc758\ub294 \ube68\ub77c\uc9c4\ub2e4. \uc608\ub97c \ub4e4\uba74 NAME, STATUS, PARENT_INCOME, SELF_INCOME\uc758 \ub124\uac1c\uc758 \uceec\ub7fc\uc73c\ub85c \uc774\ub8e8\uc5b4\uc9c4 \ud559\uc0dd \ud14c\uc774\ube14 \uc5d0\uc11c \ubd80\ubaa8\ub2d8\uc5d0 \uc758\uc874\ud558\ub294 \ud559\uc0dd\uacfc \ub3c5\ub9bd\ud55c \ud559\uc0dd\uc758 \uc774\ub984\uacfc \uc218\uc785\uc5d0 \ub300\ud574\uc11c \uc9c8\uc758\uc2dc, \uc774 \ud559\uc0dd \ud14c\uc774\ube14\uc744 \ub450\ubc88 \ucc38\uc870\ud558\uc5ec \uc9c8\uc758\ud558\uac8c \ub41c\ub2e4..\n<\/p>\n<p>SELECT NAME, PARENT_INCOME\n<\/p>\n<p>FROM STUDENT\n<\/p>\n<p>WHERE STATUS = 1\n<\/p>\n<p>UNION\n<\/p>\n<p>SELECT NAME, SELF_INCOME\n<\/p>\n<p>FROM STUDENT\n<\/p>\n<p>WHERE STATUS = 0;\n<\/p>\n<p>( NAME\uc774 \ud504\ub77c\uc774\uba38\ub9ac \ud0a4\uc774\uba70, STATUS\ub294 \ub3c5\ub9bd\ud55c \ud559\uc0dd\uc758 \uacbd\uc6b0\ub294 1, \ubd80\ubaa8\ub2d8\uc5d0 \uc758\uc874\uc801\uc778 \ud559\uc0dd\uc740 0\uc73c\ub85c \ud45c\uc2dc\ud55c\ub2e4)\n<\/p>\n<p>\uc704\uc758 \uac19\uc740 \uacb0\uacfc\ub97c \ud14c\uc774\ube14\uc744 \ub450\ubc88 \ucc38\uc870\ud558\uc9c0 \uc54a\uace0\ub3c4 \uc9c8\uc758 \ud560 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT NAME,PARENT_INCOME*STATUS + SELF_INCOME(1-STATUS)\n<\/p>\n<p>FROM STUDENT;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>17. JOIN TABLES IN THE PROPER ORDER.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub2e4\uc218\uc758 \ud14c\uc774\ube14 \uc870\uc778\uc2dc \ud14c\uc774\ube14\ub4e4\uc758 \uc870\uc778\ub418\ub294 \uc21c\uc11c\ub294 \ub9e4\uc6b0 \uc911\uc694\ud558\ub2e4. \uc804\ubc18\uc801\uc73c\ub85c, \uc62c\ubc14\ub978 \uc21c\uc11c\ub85c \ud14c\uc774\ube14\uc774 \uc870\uc778\ub418\uc5c8\ub2e4\uba74 \uc801\uc740 \uc218\uc758 \ud589\ub4e4\uc774 \uc9c8\uc758\uc2dc \ucc38\uc870\ub41c\ub2e4. \uc5b8\uc81c\ub098 \ub2e4\uc218\uc758 \uc870\uc778\ub41c \ud14c\uc774\ube14\ub4e4\uc744 \uc9c8\uc758\uc2dc \uc6b0\uc120 \uc5c4\uaca9\ud558\uac8c \uc870\uc0ac\ud558\uc5ec \ud589\ub4e4\uc758 \uc22b\uc790\ub97c \ucd5c \ub300\ud55c\uc73c\ub85c \uc904\uc778\ub2e4. \uc774\ub7ec\ud55c \ubc29\ubc95\uc73c\ub85c \uc635\ud2f0\ub9c8\uc774\uc800\ub294 \uc870\uc778\uc758 \ucc28\ud6c4 \ub2e8\uacc4\uc5d0\uc11c \uc801\uc740 \ud589\ub4e4\uc744 \uc870\uc0ac\ud558\uac8c \ub41c\ub2e4. \ubfd0\ub9cc \uc544\ub2c8\ub77c, \uc5ec\ub7ec \uc870\uc778\uc744 \ud3ec\ud568\ud558\ub294 LOOP JOIN\uc5d0\uc11c\ub294 \uac00 \uc7a5 \uba3c\uc800 \ucc38\uc870\ub418\ub294 \ud14c\uc774\ube14(DRIVING TABLE)\uc774 \ud589\ub4e4\uc744 \ucd5c\uc18c\ud55c\uc73c\ub85c \ub9ac\ud134\ud558\ub3c4\ub85d \ud574\uc57c \ud55c\ub2e4. \uadf8\ub9ac\uace0, \ub9c8\uc2a4\ud130\uc640 \uc0c1\uc138 \ud14c\uc774\ube14 \uc870\uc778\uc2dc\uc5d0\ub294(\uc608\ub97c \ub4e4\uba74 ORDER &amp; ORDER LINE ITEM TABLES) \ub9c8\uc2a4\ud130 \ud14c\uc774\ube14\uc744 \uba3c\uc800 \uc5f0\uacb0 \uc2dc\ucf1c\uc57c \ud55c\ub2e4.\n<\/p>\n<p>\uaddc\uce59\uc5d0 \uadfc\uac70\ud55c \uc635\ud2f0\ub9c8\uc774\uc800\uc758 \uacbd\uc6b0\uc5d0\ub294 FROM CLAUSE\uc758 \ub9c8\uc9c0\ub9c9 \ud14c\uc774\ube14\uc774 NESTED LOOP JOIN\uc758 DRIVING TABLE\uc774 \ub41c\ub2e4. NESTED LOOP JOIN\uc774 \ud544\uc694\ud55c \uacbd\uc6b0\uc5d0\ub294 LOOP\uc758 \uc548\ucabd\uc758 \ud14c\uc774\ube14\uc5d0\ub294 \uc778\ud14d\uc2a4\ub97c \uc774\uc6a9\ud558\ub294 \uac83\uc744 \uace0\ub824\ud560 \ub9cc\ud558\ub2e4. EXPLAIN PLAN\uacfc TKPROF\ub294 \uc870\uc778 \ud0c0\uc785, \uc870\uc778 \ud14c\uc774\ube14 \uc21c\uc11c, \uc870\uc778\uc758 \ub2e8\uacc4\ubcc4 \ucc98\ub9ac\ub41c \ud589\ub4e4 \uc758 \uc22b\uc790\ub4e4\uc744 \ub098\ud0c0\ub0b8\ub2e4. \ube44\uc6a9\uc5d0 \uadfc\uac70\ud55c \uc635\ud2f0\ub9c8\uc774\uc800\uc758 \uacbd\uc6b0\uc5d0\ub294 WHERE CLAUSE\uc5d0 \ubcf4\uc5ec\uc9c0\ub294 \ud14c\uc774\ube14\uc758 \uc21c\uc11c\ub294 \uc635\ud2f0\ub9c8\uc774\uc800\uac00 \uac00\uc7a5 \ucd5c\uc801\uc758 \uc2e4\ud589 \uacc4\ud68d\uc744 \ucc3e\uc73c\ub824\uace0 \ud558\ub294 \uac83\uacfc \uc0c1\uad00 \uc5c6\ub2e4. \uc870\uc778\ub418\ub294 \ud14c\uc774\ube14\uc758 \uc21c\uc11c\ub97c \ud1b5\uc81c\ud558\uae30 \uc704\ud574\uc11c ORDERED HINT\ub97c \uc0ac\uc6a9\ud558\ub294 \uac83\uc774 \ub0ab\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT ORDERS.CUSTID, ORDERS.ORDERNO,\n<\/p>\n<p>ORDER_LINE_ITEMS.PRODUCTNO &#8211;+ORDERED\n<\/p>\n<p>FROM ORDERS, ORDER_LINE_ITEMS\n<\/p>\n<p>WHERE ORDERS.ORDERNO = ORDER_LINE_ITEMS.ORDERNO;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>18. USE INDEX-ONLY SEARCHES WHEN POSSIBLE.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uac00\ub2a5\ud558\ub2e4\uba74, \uc778\ub371\uc2a4\ub9cc\uc744 \uc774\uc6a9\ud558\uc5ec \uc9c8\uc758\ub97c \uc0ac\uc6a9\ud558\ub77c. \uc635\ud2f0\ub9c8\uc774\uc800\ub294 \uc624\uc9c1 \uc778\ub371\uc2a4\ub9cc \uc744 \ucc3e\uc744 \uac83\uc774\ub2e4. \uc635\ud2f0\ub9c8\uc774\uc800\ub294 SQL\uc744 \ub9cc\uc871\uc2dc\ud0a4\ub294 \ubaa8\ub4e0 \uc815\ubcf4\ub97c \uc778\ub371\uc2a4\uc5d0\uc11c \ucc3e\uc744\uc218 \uc788\uc744 \ub54c, \uc778\ub371\uc2a4\ub9cc\uc744 \uc774\uc6a9\ud560 \uac83\uc774\ub2e4. \uc608\ub97c\ub4e4\uba74, EMP\ud14c\uc774\ube14\uc774 LANME\uacfc FNAME\uc758 \uc5f4\uc5d0 \ubcf5\ud569 \uc778\ub371\uc2a4\ub97c \uac00\uc9c0\uace0 \uc788\ub2e4\uba74 \ub2e4\uc74c\uc758 \uc9c8\uc758\ub294 \uc778\ub371\uc2a4\ub9cc\uc740 \uc774\uc6a9\ud560 \uac83\uc774\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT FNAME\n<\/p>\n<p>FROM EMP\n<\/p>\n<p>WHERE LNAME = &#8221;SMITH&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ubc18\uba74\uc5d0 \ub2e4\uc74c\uc758 \uc9c8\uc758\ub294 \uc778\ub371\uc2a4\uc640 \ud14c\uc774\ube14\uc744 \ubaa8\ub450 \ucc38\uc870\ud55c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT FNAME , SALARY\n<\/p>\n<p>FROM EMP\n<\/p>\n<p>WHERE LNAME = &#8221;SMITH&#8221;;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>19. REDUNDANCY IS GOOD.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>WHERE CLAUSE\uc5d0 \uac00\ub2a5\ud55c\ud55c \ub9ce\uc740 \uc815\ubcf4\ub97c \uc81c\uacf5\ud558\ub77c. \uc608\ub97c \ub4e4\uba74 WHERE COL1 = COL2 AND COL1 = 10\uc774\ub77c\uba74 \uc635\ud2f0\ub9c8\uc774\uc800\ub294 COL2=10\uc774\ub77c\uace0 \ucd94\ub860\ud558\uc9c0\ub9cc, WHERE COL1 = COL2 AND COL2 = COL3\uc774\uba74 COL1=COL3\uc774\ub77c\uace0 \ucd08\ub860\ud558\uc9c0\ub294 \uc54a\ub294\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>20. KEEP IT SIMPLE, STUPID.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\uac00\ub2a5\ud558\uba74 SQL\ubb38\uc744 \uac04\ub2e8\ud558\uac8c \ub9cc\ub4e4\ub77c. \ub9e4\uc6b0 \ubcf5\uc7a1\ud55c SQL\ubb38\uc740 \uc635\ud2f0\ub9c8\uc774\uc800\ub97c \ubb34\ub825\ud654\uc2dc\ud0ac \uc218\ub3c4 \uc788\ub2e4. \ub54c\ub85c\ub294 \ub2e4\uc218\uc758 \uac04\ub2e8\ud55c SQL\ubb38\uc774 \ub2e8\uc77c\uc758 \ubcf5\uc7a1\ud55c SQL\ubb38\ubcf4\ub2e4 \uc131\ub2a5\uc774 \uc88b\uc744 \uc218\ub3c4 \uc788\ub2e4. \uc624\ub77c\ud074\uc758 \ube44\uc6a9\uc5d0 \uadfc\uac70\ud55c \uc635\ud2f0\ub9c8\uc774\uc800\ub294 \uc544\uc9c1\uc740 \uc644\ubcbd\ud558\uc9c0 \uc54a\ub2e4. \uadf8\ub798\uc11c EXPLAIN PLAN\uc5d0 \uc8fc\uc758\ub97c \uae30\uc6b8\uc5ec\uc57c \ud55c\ub2e4. \uc5ec\uae30\uc11c \ube44\uc6a9\uc774\ub780 \uc0c1\ub300\uc801\uc778 \uac1c\ub150\uc774\uae30\uc5d0 \uc815\ud655\ud788 \uadf8\uac83\uc774 \ubb34\uc5c7\uc744 \uc758\ubbf8\ud558\ub294\uc9c0 \uc54c\uc9c0 \ubaa9\ud55c\ub2e4. \ud558\uc9c0\ub9cc \ubd84\uba85\ud55c \uac83\uc740 \uc801\uc740 \ube44\uc6a9\uc774 \ubcf4\ub2e4 \uc88b\uc740 \uc131\ub2a5\uc744 \uc758\ubbf8\ud55c\ub2e4\ub294 \uac83\uc774\ub2e4.\n<\/p>\n<p>\uc885\uc885 \uc784\uc2dc \ud14c\uc774\ube14\uc744 \uc0ac\uc6a9\ud558\uc5ec \ub9ce\uc740 \ud14c\uc774\ube14\ub4e4\uc744 \ud3ec\ud568\ud558\ub294 \ubcf5\uc7a1\ud55c SQL \uc870\uc778\uc744 \ucabc\uac1c\ub294 \uac83\uc774 \ud6a8\uc728\uc801\uc77c \uc218\ub3c4 \uc788\ub2e4. \uc608\ub97c \ub4e4\uba74, \uc870\uc778\uc774 \ub300\ub7c9\uc758 \ub370\uc774\ud130\uac00 \uc788\ub294 8\uac1c\uc758 \ud14c\uc774\ube14\uc744 \ud3ec\ud568\ud560 \ub54c, \ubcf5\uc7a1\ud55c SQL\uc744 \ub450 \uc138\uac1c\uc758 SQL\ub85c \ucabc\uac1c\ub294 \uac83\uc774 \ub0ab\uc744 \uc218 \uc788\ub2e4. \uac01\uac01\uc758 \uc9c8\uc758\ub294 \ub9ce\uc544\uc57c \ub124\uac1c\uc815\ub3c4\uc758 \ud14c\uc774\ube14\ub4e4\uc744 \ud3ec\ud568\ud558\uba70 \uadf8 \uc911\uac04 \uac12\uc744 \uc800\uc7a5 \ud558\ub294 \uac83\uc774 \ub0ab\uc744 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>21. YOU CAN REACH THE SAME DESTINATION IN DIFFERENT WAYS.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ub9ce\uc740 \uacbd\uc6b0\uc5d0, \ud558\ub098 \uc774\uc0c1\uc758 SQL\ubb38\uc740 \uc758\ub3c4\ud55c \uac19\uc740 \uacb0\uacfc\ub97c \uc904 \uc218 \uc788\ub2e4. \uac01\uac01\uc758 SQL\uc740 \ub2e4\ub978 \uc811\uadfc \uacbd\ub85c\ub97c \uc0ac\uc6a9\ud558\uba70 \ub2e4\ub974\uac8c \uc218\ud589\ud55c\ub2e4. \uc608\ub97c\ub4e4\uba74, MINUS(-) \uc0b0\uc220\uc790\ub294 WHERE NOT IN (SELECT ) OR WHERE NOT EXISTS \ubcf4\ub2e4 \ub354 \ube60\ub974\ub2e4.\n<\/p>\n<p>\uc608\ub97c\ub4e4\uba74, STATE\uc640 AREA_CODE\uc5d0 \uac01\uac01 \ub2e4\ub978 \uc778\ub371\uc2a4\uac00 \uac78\ub824 \uc788\ub2e4. \uc778\ub371\uc2a4\uc5d0\ub3c4 \ubd88\uad6c\ud558\uace0 \ub2e4\uc74c\uc758 \uc9c8\uc758\ub294 NOT IN\uc758 \uc0ac\uc6a9\uc73c\ub85c \uc778\ud574 \ud14c\uc774\ube14 \uc804\uccb4\ub97c \uc870\uc0ac\ud558\uac8c \ub41c\ub2e4.\n<\/p>\n<p>SELECT CUSTOMER_ID\n<\/p>\n<p>FROM CUSTOMERS\n<\/p>\n<p>WHERE STATE IN (&#8221;VA&#8221;, &#8221;DC&#8221;, &#8221;MD&#8221;)\n<\/p>\n<p>AND AREA_CODE NOT IN (804, 410);\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uadf8\ub7ec\ub098 \uac19\uc740 \uc9c8\uc758\uac00 \ub2e4\uc74c \ucc98\ub7fc \uc4f0\uc5ec\uc9c4\ub2e4\uba74 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uac8c \ub41c\ub2e4\n<\/p>\n<p>SELECT CUSTOMER_ID\n<\/p>\n<p>FROM CUSTOMERS\n<\/p>\n<p>WHERE STATE IN (&#8221;VA&#8221;, &#8221;DC&#8221;, &#8221;MD&#8221;)\n<\/p>\n<p>MINUS\n<\/p>\n<p>SELECT CUSTOMER_ID\n<\/p>\n<p>FROM CUSTOMERS\n<\/p>\n<p>WHERE AREA_CODE IN (804, 410);\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>WHERE\uc808\uc5d0 OR\uc744 \ud3ec\ud568\ud55c\ub2e4\uba74 OR\ub300\uc2e0\uc5d0 UNION\uc744 \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4. \uadf8\ub798\uc11c, SQL \uc9c8\uc758\ub97c \uc218\ud589\ud558\uae30 \uc804\uc5d0 \uba3c\uc800 \uc2e4\ud589\uacc4\ud68d\uc744 \uc870\uc2ec\uc2a4\ub7fd\uac8c \ud3c9\uac00\ud574\uc57c \ud55c\ub2e4. \uc774\ub7ec\ud55c \ud3c9\uac00\ub294 EXPLAIN PLAN AND TKPROF\ub97c \uc774\uc6a9\ud558\uc5ec \ud560 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>22. USE THE SPECIAL COLUMNS.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>ROWID AND ROWNUM \uc5f4\uc744 \uc774\uc6a9\ud558\ub77c. ROWID\ub97c \uc774\uc6a9\ud558\ub294 \uac83\uc774 \uac00\uc7a5 \ube60\ub974\ub2e4. \uc608\ub97c\ub4e4\uba74, ROWID\ub97c \uc774\uc6a9\ud55c UPDATE\ub294 \ub2e4\uc74c\uacfc \uac19\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT ROWID, SALARY\n<\/p>\n<p>INTO TEMP_ROWID, TEMP_SALARY\n<\/p>\n<p>FROM EMPLOYEE;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>UPDATE EMPLOYEE\n<\/p>\n<p>SET SALARY = TEMP_SALARY * 1.5\n<\/p>\n<p>WHERE ROWID = TEMP_ROWID;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>ROWID\uac12\uc740 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0\uc11c \uc5b8\uc81c\ub098 \uac19\uc9c0\ub294 \uc54a\ub2e4. \uadf8\ub798\uc11c, SQL\uc774\ub098 \uc751\uc6a9 \ud504\ub85c\uadf8\ub7a8\uc774\uc6a9\uc2dc ROWID\uac12\uc744 \uc808\ub300\ud654 \uc2dc\ud0a4\uc9c0 \ub9d0\ub77c. \ub9ac\ud134\ub418\ub294 \ud589\ub4e4\uc758 \uc22b\uc790\ub97c \uc81c\ud55c \uc2dc\ud0a4\uae30\uc704\ud574 ROWNUM\uc744 \uc774\uc6a9\ud558\ub77c. \ub9cc\uc57d\uc5d0 \ub9ac\ud134\ub418\ub294 \ud589\ub4e4\uc744 \uc815\ud655\ud788 \ubaa8\ub978\ub2e4\uba74 \ub9ac\ud134\ub418\ub294 \ud589\ub4e4\uc758 \uc22b\uc790\ub97c \uc81c\ud55c\ud558\uae30\uc704\ud574 ROWNUM\uc744 \uc0ac\uc6a9\ud558\ub77c\n<\/p>\n<p>\ub2e4\uc74c\uc758 \uc9c8\uc758\ub294 100\uac1c \uc774\uc0c1\uc758 \ud589\ub4e4\uc744 \ub9ac\ud134\ud558\uc9c0\ub294 \uc54a\ub294\ub2e4.\n<\/p>\n<p>SELECT EMPLOYE.SS#, DEPARTMENT.DEPT_NAME\n<\/p>\n<p>FROM EMPLOYEE, DEPENDENT\n<\/p>\n<p>WHERE EMPLOYEE.DEPT_ID = DEPARTMENT.DEPT_ID\n<\/p>\n<p>AND ROWNUM &lt; 100;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>23.\ud568\ucd95\uc801\uc778 \ucee4\uc11c\ub300\uc2e0 \uba85\uc2dc\uc801\uc778 \ucee4\uc11c\ub97c \uc0ac\uc6a9\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ud568\ucd95\uc801 \ucee4\uc11c\ub294 \uc5ec\ubd84\uc758 FETCH\ub97c \ubc1c\uc0dd\uc2dc\ud0a8\ub2e4. \uba85\uc2dc\uc801 \ucee4\uc11c\ub294 DECLARE, OPEN, FETCH\uc640 CLOSE CURSOR\ubb38\uc744 \uc0ac\uc6a9\ud558\uc5ec \uac1c\ubc1c\uc790\uc5d0 \uc758\ud574\uc11c \uc0dd\uc131\ub41c\ub2e4. \ud568\ucd95 \ucee4\uc11c\ub294 DELETE, UPDATE, INSERT\uc640 SELECT\ubb38\uc744 \uc0ac\uc6a9\ud558\uba74 \uc624\ub77c\ud074\uc5d0 \uc758\ud574\uc11c \uc0dd\uc131 \ub41c\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red; font-size:12pt\"><strong>24.\uc624\ub77c\ud074 \ubcd1\ub82c \ucffc\ub9ac \uc635\uc158\uc744 \ucc3e\uc544\uc11c \uc774\uc6a9\ud558\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>\ubcd1\ub82c \ucffc\ub9ac \uc635\uc158\uc744 \uc0ac\uc6a9\ud558\uba74, \ubcf4\ub2e4 \ube60\ub978 \uc131\ub2a5\uc73c\ub85c SQL\uc744 \ubcd1\ub82c\ub85c \uc2e4\ud589\ud560 \uc218 \uc788\ub2e4. \uc624\ub77c\ud074 7\uc5d0\uc11c\ub294, \uc624\uc9c1 FULL TABLE SCAN\uc5d0 \uae30\ubc18\ud55c \ucffc\ub9ac\ub9cc\uc774 \ubcd1\ub82c\ub85c \uc218\ud589\ub420 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\uc624\ub77c\ud074 8\uc5d0\uc11c\ub294, \uc778\ub371\uc2a4\uac00 \ubd84\ud560\ub418\uc5b4\uc788\ub2e4\uba74 INDEXED RANGE SCANS\uc5d0 \uae30\ubc18\ud55c \ucffc\ub9ac\ub3c4 \ubcd1\ub82c\ub85c \ucc98\ub9ac\ub420 \uc218 \uc788\ub2e4. \ubcd1\ub82c \ucffc\ub9ac \uc635\uc158\uc740 \ub2e4\uc218\uc758 \ub514\uc2a4\ud06c \ub4dc\ub77c\uc774\ubc84\ub97c \ud3ec\ud568\ud558\ub294 SMP\uc640 MPP SYSTEM\uc5d0\uc11c\ub9cc \uc0ac\uc6a9\ub420 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uc624\ub77c\ud074 \uc11c\ubc84\ub294 \ub9ce\uc740 \uc6b0\uc218\ud55c \ud2b9\uc131\uc744 \uac00\uc9c0\uace0 \uc788\uc9c0\ub9cc, \uc774\ub7ec\ud55c \ud2b9\uc131\uc758 \uc874\uc7ac\ub9cc\uc73c\ub85c\ub294 \ube60\ub978 \uc131\ub2a5\uc744 \ubcf4\uc7a5\ud558\uc9c0 \uc54a\ub294\ub2e4. \uc774\ub7ec\ud55c \ud2b9\uc131\uc744 \uc704\ud574\uc11c \ub370\uc774\ud130\ubca0\uc774\uc2a4\ub97c \uc870\uc815\ud574\uc57c\ud558\uba70 \ud2b9\uc131\uc744 \uc774\uc6a9\ud558\uae30 \uc704\ud574 \ud2b9\ubcc4\ud558\uac8c SQL\uc744 \uc791\uc131\ud574\uc57c \ud55c\ub2e4.\n<\/p>\n<p>\uc608\ub97c \ub4e4\uba74, \ub2e4\uc74c\uc758 SQL\uc740 \ubcd1\ub82c\ub85c \uc218\ud589\ub420 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>SELECT * &#8211;+PARALLEL(ORDERS,6)\n<\/p>\n<p>FROM ORDERS;\n<\/p>\n<p>\n&nbsp;<\/p>\n<p><span style=\"color:red\"><strong>25.\ub124\ud2b8\uc6cd \uc18c\ud1b5\ub7c9\uc744 \uc904\uc774\uace0 \ud55c\ubc88\uc5d0 \ucc98\ub9ac\ub418\ub294 \uc791\uc5c5\ub7c9\uc744 \ub298\ub824\ub77c.<br \/>\n<\/strong><\/span><\/p>\n<p>\n&nbsp;<\/p>\n<p>ARRAY PROCESSING\uacfc PL\/SQL BLOCK\uc744 \uc0ac\uc6a9\ud558\uba74 \ubcf4\ub2e4 \ub098\uc740 \uc131\ub2a5\uc744 \uc5bb\uc744 \uc218 \uc788\uace0 \ub124\ud2b8\uc6cd \uc18c\ud1b5\ub7c9\uc744 \uc904\uc778\ub2e4. ARRAY PROCESSING\uc740 \ud558\ub098\uc758 SQL\ubb38\uc73c\ub85c \ub9ce\uc740 ROW\ub97c \ucc98\ub9ac\ud560 \uc218 \uc788\uac8c \ud55c\ub2e4. \uc608\ub97c \ub4e4\uba74, INSERT\ubb38\uc5d0\uc11c \ubc30\uc5f4\uc744 \uc0ac\uc6a9\ud558\uba74 \ud14c\uc774\ube14\ub0b4\uc758\n<\/p>\n<p>1,000 ROW\ub97c \uc0bd\uc785\ud560 \uc218 \uc788\ub2e4. \uc774\ub7ec\ud55c \uae30\uc220\uc744 \uc0ac\uc6a9\ud558\uba74 \uc8fc\uc694\ud55c \uc131\ub2a5 \ud5a5\uc0c1\uc744 \ud074\ub77c\uc774\uc5b8\ud2b8\/\uc11c\ubc84\uc640 \ubc30\uce58\uc2dc\uc2a4\ud15c\uc5d0\uc11c \uc5bb\uc5b4\uc9c8 \uc218 \uc788\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\ubcf5\ud569 SQL\ubb38\uc740 \uacfc\ub3c4\ud55c \ub124\ud2b8\uc6cd \uc18c\ud1b5\uc744 \uc720\ubc1c\ud560 \uc218 \uc788\ub2e4. \uadf8\ub7ec\ub098 \ub9cc\uc77c SQL\ubb38\uc774 \ub2e8 \uc77c PL\/SQL \ube14\ub85d\uc548\uc5d0 \uc788\ub2e4\uba74, \uc804\uccb4 \ube14\ub85d\uc740 \uc624\ub77c\ud074 \uc11c\ubc84\uc5d0 \ubcf4\ub0b4\uc838\uc11c \uadf8\uacf3\uc5d0\uc11c \uc218\ud589\ub418\uace0, \uacb0\uacfc\ub294 \ud074\ub77c\uc774\uc5b8\ud2b8\uc758 APPLICATION\uc5d0\uac8c \ub3cc\uc544\uc628\ub2e4.\n<\/p>\n<p>\n&nbsp;<\/p>\n<p>\n&nbsp;<\/p>\n<p>\n&nbsp;<\/p>\n<p>\uac1c\ubc1c\uc790\uc640 \uc0ac\uc6a9\uc790\ub294 \uc885\uc885 SQL\uc744 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0\uc11c \ub370\uc774\ud130\ub97c \uac80\uc0c9\ud558\uace0 \uc804\uc1a1\ud558\ub294 \uac04\ub2e8\ud55c \ubc29\ubc95\uc73c\ub85c \uc0ac\uc6a9\ud55c\ub2e4. \ub54c\ub54c\ub85c \uc9c1\uc811\uc801\uc73c\ub85c SQL\uc744 \uc791\uc131\ud558\uc9c0 \uc54a\uace0 \ucf54\ub4dc \ubc1c\uc0dd\uae30\ub97c \uc0ac\uc6a9\ud558\uc5ec \uc791\uc131\ud55c APPLICATION\uc740 \uc2ec\uac01\ud55c \uc131\ub2a5 \ubb38\uc81c\ub97c \uc77c\uc73c\ud0a8\ub2e4. \uc774\ub7ec\ud55c \uc131\ub2a5\n<\/p>\n<p>\uac10\ud1f4\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uac00 \ucee4\uc9c0\uba74\uc11c \uc99d\uac00\ud55c\ub2e4.  SQL\uc740 \uc720\uc5f0\ud558\uae30 \ub54c\ubb38\uc5d0, \ub2e4\uc591\ud55c SQL\ubb38\uc73c\ub85c \uac19\uc740 \uacb0\uacfc\ub97c \uc5bb\uc744 \uc218 \uc788\ub2e4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; 1.\ub370\uc774\ud130\uc640 \ube44\uc988\ub2c8\uc2a4 \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc744 \uc798 \uc54c\uc544\uc57c \ud55c\ub2e4. &nbsp; \ub3d9\uc77c\ud55c \uc815\ubcf4\ub294 \ub2e4\ub978 \ube44\uc988\ub2c8\uc2a4 \ub370\uc774\ud130 \uc6d0\ucc9c\uc73c\ub85c\ubd80\ud130 \uac80\uc0c9\ub420 \uc218 \uc788\ub2e4. \uc774\ub7ec\ud55c \uc6d0\ucc9c\uc5d0 \uc775\uc219\ud574\uc57c \ud55c\ub2e4. \ub2f9\uc2e0\uc740 \ub2f9\uc2e0\uc758 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc548\uc758 \ub370\uc774\ud130\uc758 \ud06c\uae30\uc640 \ubd84\ud3ec\ub97c \ubc18\ub4dc\uc2dc \uc54c\uc544\uc57c \ud55c\ub2e4. \ub610\ud55c SQL\uc744 \uc791\uc131\ud558\uae30 \uc804\uc5d0 \ube44\uc988\ub2c8\uc2a4 \uac1c\uccb4 \uc548\uc758 \uad00\uacc4\uc640 \uac19\uc740 \ub370\uc774\ud130 \ubaa8\ub378\uc744 \uc804\uccb4\uc801\uc73c\ub85c \uc774\ud574\ud574\uc57c \ud55c\ub2e4. \uc774\ub7ec\ud55c \uc774\ud574\ub294 \ub2f9\uc2e0\uc774 \uc5ec\ub7ec \ud14c\uc774\ube14\uc5d0\uc11c \uc815\ubcf4\ub97c \uac80\uc0c9\ud558\ub294\ub370 \uc788\uc5b4\uc11c \ubcf4\ub2e4 \uc88b\uc740 [&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":[224,225],"jetpack_featured_media_url":"","amp_enabled":true,"_links":{"self":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/461"}],"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=461"}],"version-history":[{"count":0,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/461\/revisions"}],"wp:attachment":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=461"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=461"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=461"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}