mysql\uc758 \ucd5c\ub300 \uc131\ub2a5 \ud5a5\uc0c1 \ubc29\ubc95 <\/p>\n
1) \ubc84\ud37c \ud06c\uae30 \uc870\uc815
\nmysqld \uc11c\ubc84\uac00 \uc0ac\uc6a9\ud558\ub294 \uae30\ubcf8 \ubc84\ud37c \ud06c\uae30\ub294 \ub2e4\uc74c\uc758 \uba85\ub839\uc73c\ub85c \uc54c \uc218 \uc788\ub2e4.<\/p>\n
shell> mysqld –help<\/p>\n
\uc774 \uba85\ub839\uc740 \ubaa8\ub4e0 mysqld \uc635\uc158\uc758 \ubaa9\ub85d\uacfc \uc124\uc815 \ubcc0\uc218\ub97c \ubcf4\uc5ec\uc900\ub2e4. \ucd9c\ub825\ub418\ub294 \ub0b4\uc6a9\uc740 \uae30\ubcf8\uac12\uc744
\n\ud3ec\ud568\ud558\uace0 \uc788\uc73c\uba70 \ub2e4\uc74c\uacfc \ube44\uc2b7\ud558\ub2e4.<\/p>\n
Possible variables for option –set-variable (-O) are:
\nback_log current value: 5
\nconnect_timeout current value: 5
\njoin_buffer current value: 131072
\nkey_buffer current value: 1048540
\nlong_query_time current value: 10
\nmax_allowed_packet current value: 1048576
\nmax_connections current value: 90
\nmax_connect_errors current value: 10
\nmax_join_size current value: 4294967295
\nmax_sort_length current value: 1024
\nnet_buffer_length current value: 16384
\nrecord_buffer current value: 131072
\nsort_buffer current value: 2097116
\ntable_cache current value: 64
\ntmp_table_size current value: 1048576
\nthread_stack current value: 131072
\nwait_timeout current value: 28800<\/p>\n
mysqld \uc11c\ubc84\uac00 \ud604\uc7ac \uac00\ub3d9 \uc911\uc774\uba74 \ub2e4\uc74c\uc758 \uba85\ub839\uc744 \ud1b5\ud574 \uc2e4\uc81c \ubcc0\uc218 \uac12\uc744 \ubcfc \uc218 \uc788\ub2e4.<\/p>\n
shell> mysqladmin variables<\/p>\n
\uac01 \uc635\uc158\uc740 \ubc11\uc5d0\uc11c \uc124\uba85\ud55c\ub2e4. \ubc84\ud37c \ud06c\uae30, \uae38\uc774, \uc2a4\ud0dd \ud06c\uae30\ub294 \ubc14\uc774\ud2b8\uc774\ub2e4. ‘K'(\ud0ac\ub85c\ubc14\uc774\ud2b8)
\n\ub098 ‘M'(\uba54\uac00\ubc14\uc774\ud2b8)\ub97c \uc55e\uc5d0 \ubd99\uc5ec \uac12\uc744 \uc9c0\uc815\ud560 \uc218 \uc788\ub2e4. \uc608\ub97c \ub4e4\uba74 16M\ub294 16 \uba54\uac00\ubc14\uc774\ud2b8\ub97c
\n\uac00\ub9ac\ud0a8\ub2e4. \ub300\uc18c\ubb38\uc790\ub294 \uad6c\ubcc4\ud558\uc9c0 \uc54a\ub294\ub2e4. 16M \uc640 16m\uc740 \uac19\ub2e4.<\/p>\n
-back_log
\nmysql\uc774 \uac00\uc9c8 \uc218 \uc788\ub294 \ucd5c\ub300 \uc5f0\uacb0 \uc694\uccad\uc758 \uc218. \uc774\uac83\uc740 main mysql \uc4f0\ub808\ub4dc\uac00 \ub9e4\uc6b0 \uc9e7\uc740 \uc2dc\uac04
\n\ub3d9\uc548 \ub9e4\uc6b0 \ub9ce\uc740 \uc5f0\uacb0 \uc694\uccad\uc744 \ubc1b\uc744 \ub54c \uae30\ub2a5\uc744 \ud55c\ub2e4. \uc774\ub54c \uba54\uc778 \uc4f0\ub808\ub4dc\uac00 \uc5f0\uacb0\uc744 \uccb4\ud06c\ud558\uace0 \uc0c8\ub85c\uc6b4 \uc4f0\ub808\ub4dc\ub97c \uc2dc\uc791\ud558\ub294 \ub370\ub294 \uc57d\uac04\uc758 \uc2dc\uac04\uc774 \uac78\ub9b0\ub2e4.(\uadf8\ub7ec\ub098 \uc544\uc8fc \uc9e7\uc740 \uc2dc\uac04\uc784) back_log \uac12
\n\uc740 mysql\uc774 \uc21c\uac04\uc801\uc73c\ub85c \uc0c8\ub85c\uc6b4 \uc694\uccad\uc5d0 \ub2f5\ud558\ub294 \uac83\uc744 \uba48\ucd94\uae30 \uc804\uc5d0 \uc774 \uc9e7\uc740 \uc2dc\uac04\ub3d9\uc548 \uc5bc\ub9c8\ub098
\n\ub9ce\uc740 \uc694\uccad\uc744 \uc313\uc544\ub450\uace0 \uc788\ub294\uc9c0\ub97c \uc9c0\uc815\ud55c\ub2e4. \ub9e4\uc6b0 \uc9e7\uc740 \uc2dc\uac04\ub3d9\uc548 \ub9e4\uc6b0 \ub9ce\uc740 \uc5f0\uacb0\uc774 \uc608\uc0c1\ub420 \ub54c
\n\ub9cc \uc774 \uac12\uc744 \uc99d\uac00 \uc2dc\ucf1c\uc57c \ud55c\ub2e4. \ub2e4\ub978 \ub9d0\ub85c \uc774 \uac12\uc740 tcp\/ip \uc5f0\uacb0\uc744 \ubc1b\ub294 listen queue\uc758 \ud06c\uae30\uc774\ub2e4. \uac01 \uc6b4\uc601\uccb4\uc81c\ub9c8\ub2e4 \uc774\ub7ec\ud55c \ud050\uc758 \ud06c\uae30\uc5d0 \ud55c\uacc4\uac00 \uc788\ub2e4. Unix system call listen(2) \ub9e4\ub274\uc5bc\ud398\uc774\uc9c0\uc5d0 \uc790\uc138\ud55c \uc815\ubcf4\uac00 \uc788\ub2e4. back_log\uac12\uc758 \ud55c\uacc4\ub294 \uc6b4\uc601\uccb4\uc81c \ubb38\uc11c\ub97c \ud655\uc778\ud574\ubd10\ub77c. back_log\ub97c \ucd5c\ub300\uac12\ubcf4\ub2e4 \ub354 \ub192\uc5ec\ub3c4 \ud6a8\uacfc\uac00 \uc5c6\ub2e4. <\/p>\n
-connect_timeout
\nBad handshake\uc5d0 \ubc18\uc751\ud558\uae30 \uc804\uc5d0 \uc5f0\uacb0 \ud328\ud0b7\uc744 mysql \uc11c\ubc84\uc5d0\uc11c \uae30\ub2e4\ub9ac\ub294 \uc2dc\uac04.(\ucd08)<\/p>\n
-join_buffer
\n(\uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294 \uc870\uc778\uc758) full-join\uc5d0\uc11c \uc0ac\uc6a9\ud558\ub294 \ubc84\ud37c\uc758 \ud06c\uae30. \ubc84\ud37c\ub294 \ub450 \ud14c\uc774\ube14 \uc0ac
\n\uc774\uc5d0\uc11c \uac01 full-join\ub9c8\ub2e4 \ud55c\ubc88 \ud560\ub2f9\uc774 \ub41c\ub2e4. \uc778\ub371\uc2a4\ub97c \ucd94\uac00\ud558\uc9c0 \ubabb\ud560 \ub54c \uc870\uc778 \ubc84\ud37c\ub97c \uc99d\uac00\uc2dc\ud0a4\uba74 full join\uc758 \uc18d\ub3c4\ub97c \ud5a5\uc0c1\uc2dc\ud0ac \uc218 \uc788\ub2e4. (\uc77c\ubc18\uc801\uc73c\ub85c \ube60\ub974\uac8c \uc870\uc778\uc744 \ud558\ub294 \uac00\uc7a5 \uc88b\uc740 \ubc29\ubc95
\n\uc740\uc778\ub371\uc2a4\ub97c \ucd94\uac00\ud558\ub294 \uac83\uc774\ub2e4)<\/p>\n
-key_buffer
\n\uc778\ub371\uc2a4 \ube14\ub85d\uc740 \ubc84\ud37c\ub9c1\ub418\uace0 \ubaa8\ub4e0 \uc4f0\ub808\ub4dc\uc5d0\uc11c \uacf5\uc720\ud55c\ub2e4. \ud0a4 \ubc84\ud37c\ub294 \uc778\ub371\uc2a4 \ube14\ub85d\uc5d0\uc11c \uc0ac\uc6a9\ud558\ub294
\n\ubc84\ud37c\uc758 \ud06c\uae30\uc774\ub2e4. \uc778\ub371\uc2a4\uac00 \ub9ce\uc740 \ud14c\uc774\ube14\uc5d0\uc11c delete\ub098 insert \uc791\uc5c5\uc744 \ub9ce\uc774 \ud558\uba74 \ud0a4 \ubc84\ud37c \uac12\uc744
\n\uc99d\uac00 \uc2dc\ud0a4\ub294 \uac83\uc774 \uc88b\ub2e4. \ub354 \ube60\ub978 \uc18d\ub3c4\ub97c \ub0b4\ub824\uba74 LOCK TABLES\ub97c \uc0ac\uc6a9\ud558\uc790<\/p>\n
-max_allowed_packet
\n\ud55c \ud328\ud0b7\uc758 \ucd5c\ub300 \ud06c\uae30. \uba54\uc2dc\uc9c0 \ubc84\ud37c\ub294 net_buffer_length \ubc14\uc774\ud2b8\ub85c \ucd08\uae30\ud654\ub418\uc9c0\ub9cc \ud544\uc694\ud558\uba74 \ucd5c
\n\ub300 \ud5c8\uc6a9 \ud328\ud0b7 \ubc14\uc774\ud2b8\ub97c \uc99d\uac00\uc2dc\ud0ac \uc218 \uc788\ub2e4.\uae30\ubcf8\uac12\uc740 \ud070 \ud328\ud0b7\uc744 \uc7a1\uae30\uc5d0\ub294 \uc791\ub2e4. \uac70\ub300 BLOB
\n\uceec\ub7fc\uc744 \uc0ac\uc6a9\ud55c\ub2e4\uba74 \uac12\uc744 \uc99d\uac00 \uc2dc\ucf1c\uc57c \ud55c\ub2e4. \uc0ac\uc6a9\uc790\uac00 \uc6d0\ud558\ub294 \ucd5c\ub300 blob\ub9cc\ud07c \ud06c\uac8c \ud574\uc57c \ud55c\ub2e4. <\/p>\n
-max_connections
\n\ub3d9\uc2dc \ud074\ub77c\uc774\uc5b8\ud2b8 \uc22b\uc790. mysqld\uac00 \ud544\uc694\ub85c \ud558\ub294 \ud30c\uc77c \uc9c0\uc2dc\uc790(descriptor)\uc758 \uc22b\uc790\ub9cc\ud07c \uac12\uc744 \ub298\ub824
\n\uc57c \ud55c\ub2e4. \ubc11\uc5d0\uc11c \ud30c\uc77c \ub514\uc2a4\ud06c\ub9bd\ud130 \uc81c\ud55c\uc5d0 \ub300\ud55c \ub0b4\uc6a9\uc744 \ucc38\uace0\ud558\uc790.<\/p>\n
-max_connect_errors
\n\ud638\uc2a4\ud2b8\uc5d0\uc11c \ucd5c\ub300 \uc5f0\uacb0 \uc5d0\ub7ec\uc774\uc0c1\uc758 interrupted \uc5f0\uacb0\uc774 \uc788\uc73c\uba74 \ub354 \ub9ce\uc740 \uc5f0\uacb0\uc744 \uc704\ud574 \ud638\uc2a4\ud2b8\ub294
\nblock\ud654\ub41c\ub2e4. FLUSH HOSTS \uba85\ub839\uc73c\ub85c \ud638\uc2a4\ud2b8\uc758 block\uc744 \ud574\uc81c\ud560 \uc218 \uc788\ub2e4.<\/p>\n
-max_join_size
\n\ucd5c\ub300 \uc870\uc778 \ud06c\uae30\uc774\uc0c1\uc73c\ub85c \ub808\ucf54\ub4dc\ub97c \uc77d\ub294 \uc870\uc778\uc744 \ud558\uba74 \uc5d0\ub7ec\uac00 \ub09c\ub2e4. \ub9cc\uc57d \uc0ac\uc6a9\uc790\uac00 where \ubb38
\n\uc744 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\uace0 \uc2dc\uac04\uc774 \ub9ce\uc774 \uac78\ub9ac\uba74\uc11c \uba87 \ubc31\ub9cc\ub9cc \uac1c\uc758 \ub808\ucf54\ub4dc\ub97c \uc77d\ub294 \uc870\uc778\uc744 \uc218\ud589\ud558\ub824 \ud558\uba74 \uc774 \uac12\uc744 \uc124\uc815\ud55c\ub2e4.<\/p>\n
-max_sort_length
\nBLOB\ub098 TEXT \uac12\uc73c\ub85c \uc815\ub82c\ud560\ub54c \uc0ac\uc6a9\ud558\ub294 \ubc14\uc774\ud2b8\uc758 \uc22b\uc790. (\uac01\uac12 \uc911 \uc624\uc9c1 \uccab\ubc88\uc9f8 max_sort
\n_length \ubc14\uc774\ud2b8\ub9cc \uc0ac\uc6a9\ub41c\ub2e4. \ub098\uba38\uc9c0\ub294 \ubb34\uc2dc\ub41c\ub2e4)<\/p>\n
-net_buffer_length
\n\uc9c8\uc758\uc5d0\uc11c \ud1b5\uc2e0 \ubc84\ud37c\uac00 \ucd08\uae30\ud654\ub418\ub294 \ud06c\uae30. \uc77c\ubc18\uc801\uc73c\ub85c \ubc14\ub00c\uc9c0 \uc54a\uc9c0\ub9cc \ub9e4\uc6b0 \uc801\uc740 \uba54\ubaa8\ub9ac\ub97c \uac00
\n\uc9c0\uace0 \uc788\uc744 \ub54c \uc608\uc0c1\ub418\ub294 \uc9c8\uc758\uc5d0 \ub9de\uac8c \uc138\ud305\ud560 \uc218 \uc788\ub2e4. (\uc774\uac83\uc740 \ud074\ub77c\uc774\uc5b8\ud2b8\uc5d0 \uac00\ub294 \uc608\uc0c1\ub41c sql
\n\ubb38\uc758 \uae38\uc774\uc774\ub2e4. \uc9c8\uc758\ubb38\uc774 \uc774 \ud06c\uae30\ub97c \ub118\uc73c\uba74 \ubc84\ud37c\ub294 \uc790\ub3d9\uc73c\ub85c max_allowed_packet \ubc14\uc774\ud2b8\uae4c\uc9c0 \uc99d\uac00\ud55c\ub2e4) <\/p>\n
-record_buffer
\n\uc21c\ucc28\uc801\uc778 \uac80\uc0c9\uc744 \ud558\ub294 \uac01 \uc4f0\ub808\ub4dc\uc5d0\uc11c \uac01 \uac80\uc0c9 \ud14c\uc774\ube14\uc5d0 \ud560\ub2f9\ud558\ub294 \ubc84\ud37c \ud06c\uae30. \uc21c\ucc28\uc801\uc778 \uac80\uc0c9
\n\uc744 \ub9ce\uc774 \ud558\uba74 \uc774 \uac12\uc744 \uc99d\uac00 \uc2dc\ucf1c\uc57c \ud55c\ub2e4.<\/p>\n
-sort_buffer
\n\uc815\ub82c\uc774 \ud544\uc694\ud55c \uac01 \uc4f0\ub808\ub4dc\uc5d0\uc11c \ud560\ub2f9\ud558\ub294 \ubc84\ud37c \ud06c\uae30. order by \ub098 group by \uc624\ud37c\ub808\uc774\uc158\uc744 \ube60\ub974\uac8c \ud558\ub824\uba74 \uc774 \uac12\uc744 \uc99d\uac00 \uc2dc\ud0a8\ub2e4. <\/p>\n
-table_cache
\n\ubaa8\ub4e0 \uc4f0\ub808\ub4dc\uc5d0\uc11c \uc5f4 \uc218 \uc788\ub294 \ud14c\uc774\ube14\uc758 \uc22b\uc790. mysqld\uac00 \ud544\uc694\ub85c \ud558\ub294 \ud30c\uc77c \ub514\uc2a4\ud06c\ub9bd\ud130\uc758 \uc22b\uc790\ub9cc\ud07c \uc774 \uac12\uc744 \uc99d\uac00 \uc2dc\ud0a8\ub2e4. mysql\uc740 \uac01 \uc720\uc77c\ud55c \uc624\ud508 \ud14c\uc774\ube14\uc5d0\uc11c \ub450\uac1c\uc758 \ud30c\uc77c \ub514\uc2a4\ud06c\ub9bd\ud130\uac00
\n\ud544\uc694\ud558\ub2e4. <\/p>\n
-tmp_table_size
\n\uc784\uc2dc \ud14c\uc774\ube14\uc774 \uc774 \uac12\uc744 \ub118\uc73c\uba74 mysql\uc740 “The Table tbl_name is full”\uc774\ub77c\ub294 \uc5d0\ub7ec \uba54\uc2dc\uc9c0\ub97c
\n\ub0b8\ub2e4. \ub9e4\uc6b0 \ub9ce\uc740 group by \uc9c8\uc758\ub97c \uc0ac\uc6a9\ud558\uba74 \uc774 \uac12\uc744 \uc99d\uac00 \uc2dc\ucf1c\uc57c \ud55c\ub2e4.<\/p>\n
-thread_stack
\n\uac01 \uc4f0\ub808\ub4dc\uc758 \uc2a4\ud0dd \uc0ac\uc774\uc988. creash-me test(\ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ubca4\uce58\ub9c8\ud0b9\uc744 \ud558\ub294 \ud14c\uc2a4\ud2b8\uc774\ub2e4.)\uc5d0\uc11c \uc7a1\ud788\ub294 \ub9ce\uc740 \uc81c\ud55c\uc740 \uc774 \uac12\uc5d0 \ub2ec\ub824\uc788\ub2e4. \uae30\ubcf8\uac12\uc740 \uc77c\ubc18\uc801\uc73c\ub85c \ucda9\ubd84\ud788 \ud06c\ub2e4. 11\uc7a5\uc758 [\ubca4\uce58\ub9c8\ud06c] \ucc38\uc870<\/p>\n
-wait_timeout
\n\uc5f0\uacb0\uc744 \ub04a\uae30 \uc804\uc5d0 \uc5f0\uacb0 \ud65c\ub3d9(activity)\uc744 \uc11c\ubc84\uc5d0\uc11c \uae30\ub2e4\ub9ac\ub294 \uc2dc\uac04(\ucd08).<\/p>\n
table_cache \uc640 max_connections\ub294 \uc11c\ubc84\uac00 \uc5f4 \uc218 \uc788\ub294 \ucd5c\ub300 \ud30c\uc77c \uac2f\uc218\uc5d0 \uc601\ud5a5\uc744 \ubbf8\uce5c\ub2e4. \uc774
\n\uac12\uc744 \uc99d\uac00 \uc2dc\ud0a4\uba74 \uc6b4\uc601\uc2dc\uc2a4\ud15c\uc5d0\uc11c \uc624\ud508 \ud30c\uc77c \ub514\uc2a4\ud06c\ub9bd\ud130\uc758 per-process \uc22b\uc790\uc758 \ud55c\uacc4\uae4c\uc9c0 \uc62c
\n\ub9b4 \uc218 \uc788\ub2e4. \uadf8\ub7ec\ub098 \ub9ce\uc740 \uc2dc\uc2a4\ud15c\uc5d0\uc11c \uc774 \ud55c\uacc4\ub97c \uc99d\uac00\uc2dc\ud0ac\uc218 \uc788\ub2e4. \uc774\ub807\uac8c \ud558\ub824\uba74 \uac01 \uc2dc\uc2a4\ud15c\uc5d0\uc11c \uc774 \ud55c\uacc4\ub97c \ubcc0\ud654 \uc2dc\ud0a4\ub294 \ubc29\ubc95\uc774 \ub9e4\uc6b0 \ub2e4\uc591\ud558\ubbc0\ub85c \uc6b4\uc601\uccb4\uc81c \ubb38\uc11c\ub97c \ucc38\uace0\ud574\uc57c \ud55c\ub2e4.<\/p>\n
table_cache \ub294 max_connections \uc640 \uad00\uacc4\uac00 \uc788\ub2e4. \uc608\ub97c \ub4e4\uba74 200\uac1c\uc758 \uc5f0\uacb0\uc774 \uc788\uc73c\uba74 \ucd5c\uc18c 2
\n00 * n \uc758 \ud14c\uc774\ube14 \uce90\uc26c\ub97c \uac00\uc838\uc57c \ud55c\ub2e4. \uc5ec\uae30\uc11c n\uc740 \uc870\uc778\uc5d0\uc11c \ud14c\uc774\ube14\uc758 \ucd5c\ub300 \uc22b\uc790\uc774\ub2e4.<\/p>\n
mysql\uc740 \ub9e4\uc6b0 \uc720\uc6a9\ud55c \uc54c\uace0\ub9ac\uc998\uc744 \uc0ac\uc6a9\ud558\uae30 \ub54c\ubb38\uc5d0 \uc77c\ubc18\uc801\uc73c\ub85c\ub294 \ub9e4\uc6b0 \uc801\uc740 \uba54\ubaa8\ub9ac\ub85c \uc0ac\uc6a9
\n\ud560 \uc218 \uc788\uc73c\uba70 \uba54\ubaa8\ub9ac\uac00 \ub9ce\uc744 \uc218\ub85d \uc131\ub2a5\uc774 \ub354 \ub9ce\uc774 \ud5a5\uc0c1\ub41c\ub2e4.<\/p>\n
\ub9ce\uc740 \uba54\ubaa8\ub9ac\uc640 \ub9ce\uc740 \ud14c\uc774\ube14\uc744 \uac00\uc84c\uace0 \uc911\uac04\uc815\ub3c4 \uc22b\uc790\uc758 \ud074\ub77c\uc774\uc5b8\ud2b8\uc5d0\uc11c \ucd5c\ub300\uc758 \uc131\ub2a5\uc744 \uc6d0\ud55c\ub2e4\uba74 \ub2e4\uc74c\uacfc \uac19\uc774 \uc0ac\uc6a9\ud55c\ub2e4.<\/p>\n
shell> safe_mysqld -O key_buffer=16M -O table_cache=128
\n-O sort_buffer=4M -O record_buffer=1M &<\/p>\n
\uba54\ubaa8\ub9ac\uac00 \uc801\uace0 \uc5f0\uacb0\uc774 \ub9ce\uc73c\uba74 \ub2e4\uc74c\uacfc \uac19\uc774 \uc0ac\uc6a9\ud55c\ub2e4.<\/p>\n
shell> safe_mysqld -O key_buffer=512k -O sort_buffer=100k
\n-O record_buffer=100k &<\/p>\n
\ub610\ub294: <\/p>\n
shell> safe_mysqld -O key_buffer=512k -O sort_buffer=16k
\n-O table_cache=32 -O record_buffer=8k -O net_buffer=1K &<\/p>\n
\ub9e4\uc6b0 \ub9ce\uc740 \uc5f0\uacb0\uc774 \uc788\uc744 \ub54c mysqld\uac00 \uac01 \uc5f0\uacb0\ub9c8\ub2e4 \ucd5c\uc18c\ud55c\uc758 \uba54\ubaa8\ub9ac\ub97c \uc0ac\uc6a9\ud558\ub3c4\ub85d \uc124\uc815\ud558\uc9c0
\n\uc54a\uc558\ub2e4\uba74 “swapping problems” \ubb38\uc81c\uac00 \uc0dd\uae38 \uac83\uc774\ub2e4.<\/p>\n
mysqld\uc5d0\uc11c \uc635\uc158\uc744 \ubc14\uafb8\uc5c8\uc73c\uba74 \uadf8\uac83\uc740 \uc11c\ubc84\uc758 \ud574\ub2f9\ud558\ub294 \uc778\uc2a4\ud134\uc2a4\uc5d0\ub9cc \uc601\ud5a5\uc744 \ubbf8\uce5c\ub2e4\ub294 \uac83
\n\uc744 \uae30\uc5b5\ud558\uc790.<\/p>\n
\uc635\uc158\uc744 \ubc14\uafb8\uc5c8\uc744 \ub54c\uc758 \ud6a8\uacfc\ub97c \ubcf4\uae30 \uc704\ud574 \ub2e4\uc74c\uacfc \uac19\uc774 \ud574\ubcf4\uc790.<\/p>\n
shell> mysqld -O key_buffer=32m –help<\/p>\n
\ub9c8\uc9c0\ub9c9\uc5d0 –help \uc635\uc158\uc774 \ub4e4\uc5b4\uac04 \uac83\uc744 \uae30\uc5b5\ud558\uc790. \uadf8\ub807\uc9c0 \uc54a\uc73c\uba74 \ucee4\ub9e8\ub4dc \ub77c\uc778\uc5d0\uc11c \uc0ac\uc6a9\ud55c \uc635\uc158\uc758 \ud6a8\ub825\uc740 \ucd9c\ub825\uc5d0\ub294 \ubc18\uc601\ub418\uc9c0 \uc54a\uc744 \uac83\uc774\ub2e4. <\/p>\n
2) \uba54\ubaa8\ub9ac \uc0ac\uc6a9 \ubc29\ubc95 <\uba54\ubaa8\ub9ac \ucd5c\uc801\ud654><\/p>\n
\uc544\ub798\uc5d0\uc11c \uc124\uba85\ud558\ub294 \ubaa9\ub85d\uc740 mysqld \uc11c\ubc84\uac00 \uba54\ubaa8\ub9ac\ub97c \uc0ac\uc6a9\ud558\ub294 \ubc29\ubc95\uc5d0 \ub300\ud574\uc11c \ub098\ud0c0\ub0b4\uace0 \uc788
\n\ub2e4. \uba54\ubaa8\ub9ac \uc0ac\uc6a9\uacfc \uad00\ub828\ub41c \uc11c\ubc84\uc758 \ubcc0\uc218 \uc774\ub984\uc774 \uc8fc\uc5b4\uc9c4\ub2e4.<\/p>\n
– \ud0a4 \ubc84\ud37c(\ubcc0\uc218 key_buffer)\ub294 \ubaa8\ub4e0 \uc4f0\ub808\ub4dc\uc5d0\uc11c \uacf5\uc720\ud55c\ub2e4. \uc11c\ubc84\uc5d0\uc11c \uc0ac\uc6a9\ud558\ub294 \ub2e4\ub978 \ubc84\ud37c\ub294
\n\ud544\uc694\ud55c\ub300\ub85c \ud560\ub2f9\uc774 \ub41c\ub2e4.<\/p>\n
– \uac01 \uc5f0\uacb0\uc740 \uac01 \uc4f0\ub808\ub4dc \ub9c8\ub2e4 \ud2b9\uc815\ud55c \uacf5\uac04\uc744 \uc0ac\uc6a9\ud55c\ub2e4. \uc2a4\ud0dd(64k, \ubcc0\uc218 thread_stack) , \uc5f0\uacb0
\n\ubc84\ud37c(\ubcc0\uc218 net_buffer_length), result \ubc84\ud37c (\ubcc0\uc218 net_buffer_length) \ub4f1. \uc5f0\uacb0 \ubc84\ud37c\uc640 result
\n\ubc84\ud37c\ub294 \ud544\uc694\ud560 \ub54c max_allowed_packet \uae4c\uc9c0 \ub3d9\uc801\uc73c\ub85c \uc99d\uac00\ub41c\ub2e4. \uc9c8\uc758\uac00 \uc218\ud589\ub420 \ub54c \ud604\uc7ac\uc758
\n\uc9c8\uc758\ubb38\uc758 \ubcf5\uc0ac\ubb38\uc774 \ub610\ud55c \ud560\ub2f9\uc774 \ub41c\ub2e4. <\/p>\n
– \ubaa8\ub4e0 \uc4f0\ub808\ub4dc\ub294 \uac19\uc740 \uae30\ubcf8 \uba54\ubaa8\ub9ac\ub97c \uacf5\uc720\ud55c\ub2e4.
\n– \uba54\ubaa8\ub9ac \ub9f5\uc740 \uc544\uc9c1 \uc9c0\uc6d0\uc774 \uc548\ub41c\ub2e4. (\uc555\ucd95 \ud14c\uc774\ube14\uc744 \uc81c\uc678\ud558\uace0. \uadf8\ub7ec\ub098 \uc774\uac83\uc740 \ub2e4\ub978 \uc774\uc57c\uae30\uc774
\n\ub2e4) \uc65c\ub0d0\ud558\uba74 4GB\uc758 32\ube44\ud2b8 \uba54\ubaa8\ub9ac \uacf5\uac04\uc740 \ub300\ubd80\ubd84\uc758 \ub300\ud615 \ud14c\uc774\ube14\uc5d0\uc11c \ucda9\ubd84\ud788 \ud06c\uae30\uac00 \uc54a\uae30
\n\ub54c\ubb38\uc774\ub2e4. \uc6b0\ub9ac\uac00 64\ube44\ud2b8 \uc8fc\uc18c \uacf5\uac04\uc744 \uac00\uc9c4 \uc2dc\uc2a4\ud15c\uc744 \uac00\uc9c0\uac8c \ub420 \ub54c \uc6b0\ub9ac\ub294 \uba54\ubaa8\ub9ac \ub9f5\ud551\uc744
\n\uc704\ud55c \uc77c\ubc18\uc801\uc778 \uc9c0\uc6d0\uc744 \ucd94\uac00\ud560 \uac83\uc774\ub2e4.<\/p>\n
– \ud14c\uc774\ube14\uc5d0\uc11c \uc21c\ucc28\uc801\uc778 \uac80\uc0c9\uc744 \ud558\ub294 \uac01 \uc694\uccad\uc740 read \ubc84\ud37c\uc5d0 \ud560\ub2f9\uc774 \ub41c\ub2e4. (\ubcc0\uc218 record_buff
\ner)<\/p>\n
– \ubaa8\ub4e0 \uc870\uc778\uc740 \ud55c\ubc88\uc5d0 \uc218\ud589\uc774 \ub418\uba70 \ub300\ubd80\ubd84\uc758 \uc870\uc778\uc740 \uc784\uc2dc \ud14c\uc774\ube14\uc744 \uc0dd\uc131\ud558\uc9c0 \uc54a\uace0 \uc218\ud589\uc774
\n\ub41c\ub2e4. \ub300\ubd80\ubd84\uc758 \ud14c\uc774\ube14\uc740 \uba54\ubaa8\ub9ac \uae30\ubc18(HEAP) \ud14c\uc774\ube14\uc774\ub2e4. \uac70\ub300 \uae38\uc774\uc758 \ub808\ucf54\ub4dc\ub97c \uac00\uc84c\uac70\ub098
\nBLOB \uceec\ub7fc\uc744 \ud3ec\ud568\ud55c \uc784\uc2dc \ud14c\uc774\ube14\uc740 \ub514\uc2a4\ud06c\uc5d0 \uc800\uc7a5\uc774 \ub41c\ub2e4. \ud604\uc7ac\uc758 \ubb38\uc81c\ub294 \uba54\ubaa8\ub9ac \uae30\ubc18 \ud14c
\n\uc774\ube14\uc774 tmp_table_size\ub97c \ucd08\uacfc\ud588\uc744 \ub54c “The table tbl_name is full”\uc774\ub77c\ub294 \uc5d0\ub7ec\uac00 \uc0dd\uae30\ub294 \uac83
\n\uc774\ub2e4. \uac00\uae4c\uc6b4 \uc2dc\uc77c \uc548\uc5d0 \ud544\uc694\ud560 \ub54c \uc790\ub3d9\uc801\uc73c\ub85c \uba54\ubaa8\ub9ac \uae30\ubc18(HEAP) \ud14c\uc774\ube14\uc744 \ub514\uc2a4\ud06c \uae30\ubc18(NI
\nSAM) \ud14c\uc774\ube14\ub85c \ubc14\uafb8\ub3c4\ub85d \uace0\uce60 \uac83\uc774\ub2e4.
\n\uc774 \ubb38\uc81c\ub97c \ud574\uacb0\ud558\uae30 \uc704\ud574\uc11c mysqld\uc758 tmp_table_size \uc635\uc158\uc744 \uc124\uc815\ud558\uc5ec \uc784\uc2dc \ud14c\uc774\ube14 \ud06c\uae30\ub97c
\n\ub298\uc774\uac70\ub098 \ud074\ub77c\uc774\uc5b8\ud2b8 \ud504\ub85c\uadf8\ub7a8\uc5d0\uc11c SQL_BIG_TABLES\ub77c\ub294 sql \uc635\uc158\uc744 \uc124\uc815\ud558\uc5ec\uc57c \ud55c\ub2e4
\nmysql 3.20\uc5d0\uc11c \uc784\uc2dc \ud14c\uc774\ube14\uc758 \ucd5c\ub300 \ud06c\uae30\ub294 record_buffer*16\uc774\ub2e4. 3.20 \ubc84\uc804\uc744 \uc0ac\uc6a9\ud558\uace0 \uc788
\n\ub2e4\uba74 record_buffer\uc758 \uac12\uc744 \uc99d\uac00\uc2dc\ucf1c\uc57c \ud55c\ub2e4. \ub610\ud55c mysqld\ub97c \uc2dc\uc791\ud560 \ub54c –big-tables \uc635\uc158\uc744
\n\uc0ac\uc6a9\ud558\uc5ec \ud56d\uc0c1 \uc784\uc2dc \ud14c\uc774\ube14\uc744 \ub514\uc2a4\ud06c\uc5d0 \uc800\uc7a5\ud560 \uc218 \uc788\uc9c0\ub9cc \uc9c8\uc758 \uc18d\ub3c4\uc5d0 \uc601\ud5a5\uc744 \ubbf8\uce5c\ub2e4.<\/p>\n
– \uc815\uc5f4\uc744 \ud558\ub294 \ub300\ubd80\ubd84\uc758 \uc694\uccad\uc740 \uc815\ub82c \ubc84\ud37c\uc640 \ud558\ub098\ub098 \ub450\uac1c\uc758 \uc784\uc2dc \ud30c\uc77c\uc744 \ud560\ub2f9\ud55c\ub2e4. <\/p>\n
– \ub300\ubd80\ubd84\uc758 \ud30c\uc9d5(parsing)\uacfc \uacc4\uc0b0\uc740 \uc9c0\uc5ed \uba54\ubaa8\ub9ac\uc5d0\uc11c \uc774\ub8e8\uc5b4\uc9c4\ub2e4. \uc791\uc740 \uc544\uc774\ud15c\uc5d0\ub294 \uba54\ubaa8\ub9ac o
\nverhead\uac00 \ud544\uc694\uc5c6\uace0 \uc77c\ubc18\uc801\uc778 \ub290\ub9b0 \uba54\ubaa8\ub9ac \ud560\ub2f9(slow memory allocation)\uacfc freeing(\uba54\ubaa8\ub9ac
\n\ud574\uc81c)\ub294 \ubb34\uc2dc\ub41c\ub2e4. \uba54\ubaa8\ub9ac\ub294 \uc624\uc9c1 \uc608\uc0c1\uc9c0 \ubabb\ud55c \uac70\ub300 \ubb38\uc790\uc5f4\uc5d0\uc11c \ud560\ub2f9\uc774 \ub41c\ub2e4.( mallloc() \uacfc
\nfree() \uc0ac\uc6a9)<\/p>\n
– \uac01 \uc778\ub371\uc2a4 \ud30c\uc77c\uc740 \ud55c\ubc88\uc5d0 \uc5f4\ub9ac\uba70 \uac01 \ubcd1\ud589\uc218\ud589\ub418\ub294 \uc4f0\ub808\ub4dc\uc5d0\uc11c \ub370\uc774\ud130 \ud30c\uc77c\uc740 \ud55c\ubc88\uc5d0 \uc5f4
\n\ub9b0\ub2e4. \uac01 \ubcd1\ud589\uc218\ud589 \uc4f0\ub808\ub4dc\ub9c8\ub2e4 \ud14c\uc774\ube14 \uad6c\uc870, \uac01 \uceec\ub7fc\uc758 \uceec\ub7fc \uad6c\uc870, 3 * n \uc758 \ubc84\ud37c \ud06c\uae30\uac00 \ud560
\n\ub2f9\ub41c\ub2e4. ( n\uc740 \ucd5c\ub300 \ub808\ucf54\ub4dc \uae38\uc774\uc774\uba70 BLOB \uceec\ub7fc\uc740 \ud574\ub2f9\ud558\uc9c0 \uc54a\ub294\ub2e4) BLOB\ub294 BLOB \ub370\uc774
\n\ud130\uc758 \uae38\uc774\uc5d0 5\uc5d0\uc11c 8 \ubc14\uc774\ud2b8\ub97c \ub354\ud55c \uac12\uc744 \uc0ac\uc6a9\ud55c\ub2e4.<\/p>\n
– BLOB \uceec\ub7fc\uc744 \uac00\uc9c4 \uac01 \ud14c\uc774\ube14\uc5d0\uc11c \ubc84\ud37c\ub294 \uac70\ub300 BLOB \uac12\uc744 \uc77d\uc744 \uc218 \uc788\ub3c4\ub85d \ub3d9\uc801\uc73c\ub85c \ucee4
\n\uc9c4\ub2e4. \ud14c\uc774\ube14\uc744 \uac80\uc0c9\ud558\uba74 \ubc84\ud37c\ub294 \ucd5c\ub300 BLOB\uc758 \uac12\ub9cc\ud07c \ubc84\ud37c\uac00 \ud560\ub2f9\uc774 \ub41c\ub2e4.<\/p>\n
– \ubaa8\ub4e0 \uc0ac\uc6a9\uc911\uc778 \ud14c\uc774\ube14\uc758 \ud14c\uc774\ube14 \ud578\ub4e4\ub7ec\ub294 \uce90\uc26c\uc5d0 \uc800\uc7a5\ub418\uba70 FIFO\ub85c \uad00\ub9ac\uac00 \ub41c\ub2e4. \uc77c\ubc18\uc801
\n\uc73c\ub85c \uce90\uc26c\ub294 64 \uc5d4\ud2b8\ub9ac\ub97c \uac16\ub294\ub2e4. \ub3d9\uc2dc\uc5d0 \ub450\uac1c\uc758 \uc2e4\ud589 \uc4f0\ub808\ub4dc\uc5d0\uc11c \ud14c\uc774\ube14\uc744 \uc0ac\uc6a9\ud558\uba74 \uce90\uc26c
\n\ub294 \ud14c\uc774\ube14\uc758 \ub450 \uc5d4\ud2b8\ub9ac\ub97c \ud3ec\ud568\ud55c\ub2e4. <\/p>\n
– mysqladmin flush-tables \uba85\ub839\uc740 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294 \ubaa8\ub4e0 \ud14c\uc774\ube14\uc744 \ub2eb\uace0 \ud604\uc7ac \uc2e4\ud589\ub418\ub294 \uc2a4\ub808
\n\ub4dc\uac00 \ub05d\ub0a0 \ub54c \ubaa8\ub4e0 \uc0ac\uc6a9\uc911\uc778 \ud14c\uc774\ube14\uc744 \ub2eb\ub294\ub2e4\uace0 \ud45c\uc2dc\ud55c\ub2e4. \uc774\uac83\uc740 \ud6a8\uacfc\uc801\uc73c\ub85c \uc0ac\uc6a9\uc911\uc778 \uba54
\n\ubaa8\ub9ac\ub97c \ud574\uc81c\ud55c\ub2e4. <\/p>\n
ps \uc640 \ub2e4\ub978 \uc2dc\uc2a4\ud15c \uc0c1\ud669 \ud504\ub85c\uadf8\ub7a8\uc740 mysqld\uac00 \ub9ce\uc740 \uba54\ubaa8\ub9ac\ub97c \uc0ac\uc6a9\ud558\uace0 \uc788\ub2e4\uace0 \ubcf4\uace0\ud560 \uac83\uc774
\n\ub2e4. \uc774\uac83\uc740 \ub2e4\ub978 \uba54\ubaa8\ub9ac \uc8fc\uc18c\uc758 \uc4f0\ub808\ub4dc-\uc2a4\ud0dd\ub54c\ubb38\uc5d0 \uc0dd\uae34\ub2e4. \uc608\ub97c \ub4e4\uba74 \uc194\ub77c\ub9ac\uc2a4\uc758 ps \ub294 \uc2a4
\n\ud0dd\uc0ac\uc774\uc758 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294 \uba54\ubaa8\ub9ac\ub97c \uc0ac\uc6a9\ud558\ub294 \uba54\ubaa8\ub9ac\ub85c \uac04\uc8fc\ud55c\ub2e4. \uc774\uac83\uc740 swap -s\ub97c \uc774\uc6a9 \uc0ac
\n\uc6a9\uac00\ub2a5\ud55c \uc2a4\uc651\uc744 \uccb4\ud06c\ud558\uc5ec \ud655\uc778\ud560\uc218 \uc788\ub2e4. \uc6b0\ub9ac\ub294 mysqld\ub97c \uc0c1\uc6a9 \uba54\ubaa8\ub9ac \uc720\ucd9c \uce21\uc815 \ud504\ub85c\uadf8
\n\ub7a8\uc73c\ub85c \ud14c\uc2a4\ud305\ud574\uc11c mysqld\uc5d0\ub294 \uba54\ubaa8\ub9ac \uc720\ucd9c\uc774 \uc5c6\ub2e4.
\n3) \uc18d\ub3c4 \ud5a5\uc0c1\uc5d0 \uc601\ud5a5\uc744 \ubbf8\uce58\ub294 \ucef4\ud30c\uc77c\/\ub9c1\ud06c \ubc29\ubc95 <\ucef4\ud30c\uc77c\uc2dc \ucd5c\uc801\ud654\ud558\uae30><\/p>\n
\ub2e4\uc74c \ud14c\uc2a4\ud2b8\uc758 \ub300\ubd80\ubd84\uc740 \ub9ac\ub205\uc2a4\uc640 mysql \ubca4\uce58\ub9c8\ud06c\ub97c \uac00\uc9c0\uace0 \uc218\ud589\ub418\uc5c8\uc9c0\ub9cc \ub2e4\ub978 \uc6b4\uc601 \uc2dc\uc2a4
\n\ud15c\uc5d0\ub3c4 \uc554\uc2dc\ud574\uc8fc\ub294 \uac83\uc774 \uc788\ub2e4. <\/p>\n
static\uc73c\ub85c \ub9c1\ud06c\ub97c \ud560 \ub54c \uac00\uc7a5 \ube60\ub978 \uc2e4\ud589 \uc18d\ub3c4\ub97c \uc5bb\uc744 \uc218 \uc788\ub2e4. \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0 \uc5f0\uacb0\ud558\uae30 \uc704
\n\ud574 TCP\/IP\ubcf4\ub2e4\ub294 \uc720\ub2c9\uc2a4 \uc18c\ucf13\uc744 \uc0ac\uc6a9\ud558\uba74 \ub354 \uc88b\uc740 \uc131\ub2a5\uc744 \ub0bc \uc218 \uc788\ub2e4. <\/p>\n
\ub9ac\ub205\uc2a4\uc5d0\uc11c pgcc\uc640 -O6\uc744 \uc0ac\uc6a9\ud558\uba74 \uac00\uc7a5 \ube60\ub974\ub2e4. ‘sql_yacc.cc’\ub97c \uc774 \uc635\uc158\uc73c\ub85c \ucef4\ud30c\uc77c \ud558\ub824\uba74
\ngcc\/pgcc\ub294 \ubaa8\ub4e0 \uc131\ub2a5\uc744 \ub0b4\uae30 \uc704\ud574 \ub9ce\uc740 \uba54\ubaa8\ub9ac\uac00 \ud544\uc694\ud558\uae30 \ub54c\ubb38\uc5d0 180M\uc758 \uba54\ubaa8\ub9ac\uac00 \ud544\uc694
\n\ud558\ub2e4. \ub610\ud55c mysql\uc744 \uc124\uc815\ud560 \ub54c libstdc++ \ub77c\uc774\ube0c\ub7ec\ub9ac\ub97c \ud3ec\ud568\ud558\uc9c0 \uc54a\uae30 \uc704\ud574 CXX=gcc\ub77c\uace0 \uc124\uc815\ud574\uc57c \ud55c\ub2e4.<\/p>\n
– pgcc\ub97c \uc0ac\uc6a9\ud558\uace0 \ubaa8\ub450\ub2e4 -O6 \uc635\uc158\uc73c\ub85c \ucef4\ud30c\uc77c\ud558\uba74 mysqld \uc11c\ubc84\ub294 gcc\ub85c \ucef4\ud30c\uc77c\ud55c \uac83\ubcf4
\n\ub2e4 11% \ube68\ub77c\uc9c4\ub2e4.<\/p>\n
– \ub3d9\uc801\uc73c\ub85c \ub9c1\ud06c\ud558\uba74 (-static\uc744 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\uace0) 13% \ub290\ub824\uc9c4\ub2e4.
\nIf you connect using TCP\/IP rather than Unix sockets, the result is 7.5% slower.
\n– \uc720\ub2c9\uc2a4 \uc18c\ucf13\uc744 \uc0ac\uc6a9\ud558\ub294 \uac83\ubcf4\ub2e4 tcp\/ip\ub85c \uc5f0\uacb0\ud558\ub294 \uac83\uc774 7.5% \ub290\ub824\uc9c4\ub2e4.<\/p>\n
– On a Sun sparcstation 10, gcc 2.7.3 is 13% faster than Sun Pro C++ 4.2.
\n– On Solaris 2.5.1, MIT-pthreads is 8-12% slower than Solaris native threads.
\n\ubc88\uc5ed\uc744 \uc548\ud55c \uc774\ud6c4. \ub9ac\ub205\uc2a4\ub791 \uc0c1\uad00\uc5c6\uc73c\ub2c8\uae50… <\/p>\n
TcX\uc5d0\uc11c \uc81c\uacf5\ud55c mysql \ub9ac\ub205\uc2a4 \ubc30\ud3ec\ud310\uc740 pgcc\ub85c \ucef4\ud30c\uc77c \ub418\uc5c8\uace0 \uc815\uc801\uc73c\ub85c \ub9c1\ud06c \ub418\uc5c8\ub2e4.<\/p>\n
4)MySQL\uc758 \uc778\ub371\uc2a4 \uc0ac\uc6a9<\/p>\n
\ubaa8\ub4e0 \uc778\ub371\uc2a4(PRIMARY, UNIQUE and INDEX()) \ub294 B-trees\uc5d0 \uc800\uc7a5\ub41c\ub2e4. \ubb38\uc790\uc5f4\uc740 \uc790\ub3d9\uc801
\n\uc73c\ub85c \uc55e \ub4a4\uc758 \uacf5\uac04\uc774 \uc555\ucd95\ub41c\ub2e4. <\/p>\n
\uc778\ub371\uc2a4\uc758 \uc0ac\uc6a9 :
\n– WHERE \ubb38\uc5d0\uc11c \ud574\ub2f9\ud558\ub294 \ub808\ucf54\ub4dc \ube68\ub9ac \ucc3e\uae30
\n– \uc870\uc778\uc744 \uc218\ud589\ud560\ub54c \ub2e4\ub978 \ud14c\uc774\ube14\uc5d0\uc11c \ub808\ucf54\ub4dc \uac00\uc838\uc624\uae30
\n– \ud2b9\uc815 \ud0a4\uc5d0\uc11c MAX() \ub098 MIN() \uac12 \ucc3e\uae30
\n– \uc18c\ud305\uc774\ub098 \uadf8\ub8f9\ud654 \ud560 \ub54c \uc778\ub371\uc2a4 \ud0a4\ub97c \uc0ac\uc6a9\ud558\uba74 \ud14c\uc774\ube14\uc744 \uc815\uc5f4\ud558\uac70\ub098 \uadf8\ub8f9\ud654\ud55c\ub2e4. \ud0a4\uc5d0 DESC\uac00 \ubd99\uc73c\uba74 \uc5ed\uc21c\uc73c\ub85c \uc778\ub371\uc2a4\ub97c \uc77d\ub294\ub2e4.
\n– \uc5b4\ub5a4 \uacbd\uc6b0\uc5d0\ub294 \ub370\uc774\ud130 \ud30c\uc77c\uc5d0 \ubb3b\uc9c0 \uc54a\uace0 \uac12\uc744 \uac00\uc838\uc628\ub2e4. \uc5b4\ub5a4 \ud14c\uc774\ube14\uc5d0\uc11c \uc0ac\uc6a9\ud558\ub294 \ubaa8\ub4e0
\n\uceec\ub7fc\uc774 \uc22b\uc790\uc774\uace0 \ud2b9\uc815 \ud0a4\ub85c \ud615\uc131\ub418\uc5b4\uc788\uc73c\uba74 \ube60\ub978 \uc18d\ub3c4\ub85c \uc778\ub371\uc2a4 \ud2b8\ub9ac\uc5d0\uc11c \uac12\uc744 \uac00\uc838\uc62c \uc218
\n\uc788\ub2e4.<\/p>\n
\ub2e4\uc74c \uc608\uc81c\ub97c \ubcf4\uc790.<\/p>\n
mysql> SELECT * FROM tbl_name WHERE col1=val1 AND col2=val2;<\/p>\n
\ub2e4\uc911 \uceec\ub7fc \uc778\ub371\uc2a4\uac00 col1 \uacfc col2\uc5d0 \uc788\uc73c\uba74 \ud574\ub2f9\ud558\ub294 \ub808\ucf54\ub4dc\ub97c \uc9c1\uc811 \uac00\uc838\uc62c \uc218 \uc788\ub2e4. \ubd84\ub9ac
\n\ub41c \ub2e8\uc77c \uceec\ub7fc \uc778\ub371\uc2a4\uac00 col1 \uacfc col2 \uc5d0 \uc788\uc73c\uba74 \ucd5c\uc801\ud654\uae30\ub294 \uc5b4\ub5a4 \uc778\ub371\uc2a4\uac00 \ub354 \uc801\uc740 \ub808\ucf54\ub4dc
\n\ub97c \uac00\uc84c\ub294\uc9c0 \ud655\uc778\ud558\uace0 \ub808\ucf54\ub4dc\ub97c \uac00\uc838\uc624\uae30 \uc704\ud574 \uadf8 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\ub3c4\ub85d \uacb0\uc815\ud55c\ub2e4.<\/p>\n
\ud14c\uc774\ube14\uc774 \ub2e4\uc911 \uceec\ub7fc \uc778\ub371\uc2a4\ub97c \uac00\uc84c\ub2e4\uba74 \ucd5c\uc801\ud654\uae30\uac00 \ub808\ucf54\ub4dc\ub97c \ucc3e\ub294\ub370 \uc5b4\ub5a4 \uc778\ub371\uc2a4\ud0a4\ub97c \uc0ac\uc6a9
\n\ud560 \uc218 \uc788\ub2e4. \uc608\ub97c \ub4e4\uba74 \uc138\uac00\uc9c0 \uceec\ub7fc \uc778\ub371\uc2a4(col1, col2, col3)\ub97c \uac00\uc84c\ub2e4\uba74 (col1), (col1,col2)
\n(col1,col2,col3) \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uc5ec \uac80\uc0c9\uc744 \ud560 \uc218 \uc788\ub2e4. <\/p>\n
mysql> SELECT * FROM tbl_name WHERE col1=val1;
\nmysql> SELECT * FROM tbl_name WHERE col2=val2;
\nmysql> SELECT * FROM tbl_name WHERE col2=val2 AND col3=val3;<\/p>\n
\uc778\ub371\uc2a4\uac00 (col1,col2,col3)\ub85c \uc788\ub2e4\uba74 \uc704\uc758 \uc9c8\uc758 \uc911 \uc624\uc9c1 \uccab\ubc88\uc9f8 \uc9c8\uc758\ub9cc \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud55c\ub2e4. \ub450
\n\ubc88\uc9f8 \ubc0f \uc138 \ubc88\uc9f8 \uc9c8\uc758\ub294 \uc778\ub371\uc2a4 \ub41c \uceec\ub7fc\uc774 \ud3ec\ud568\ub418\uc5b4 \uc788\uc9c0\ub9cc (col2) \uc640 (col2,col3)\ub294 (col1,col2,col3) \uc778\ub371\uc2a4\uc5d0 \ud574\ub2f9\ud558\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n
mysql\uc740 \ub610\ud55c LIKE\uc758 \uc778\uc218\uac00 \uc640\uc77c\ub4dc\uce74\ub4dc \ubb38\uc790\ub85c \uc2dc\uc791\ud558\uc9c0 \uc54a\ub294 \uc0c1\uc218 \ubb38\uc790\uc5f4\uc774\ub77c\uba74 LIK
\nE \ube44\uad50\ubb38\uc5d0\uc11c \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud55c\ub2e4. \uc608\ub97c \ub4e4\uc5b4 \ub2e4\uc74c\uc758 SELECT \ubb38\uc740 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud55c\ub2e4.<\/p>\n
mysql> select * from tbl_name where key_col LIKE “Patrick%”;
\nmysql> select * from tbl_name where key_col LIKE “Pat%_ck%”;<\/p>\n
\uccab\ubc88\uc9f8 \ubb38\uc7a5\uc5d0\uc11c\ub294 “Patrick” <= key_col < \"Patricl\" \uc744 \uac00\uc9c4 \ub808\ucf54\ub4dc\ub9cc \uace0\ub824\ub41c\ub2e4. \ub450 \ubc88\uc9f8 \ubb38\n\uc7a5\uc5d0\uc11c\ub294 \"Pat\" <= key_col < \"Pau\" \uc744 \uac00\uc9c4 \ub808\ucf54\ub4dc\ub9cc \uace0\ub824\ub41c\ub2e4. \n \n \n\ub2e4\uc74c\uc758 SELECT \ubb38\uc740 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\uc9c0 \uc54a\ub294\ub2e4:\n \nmysql> select * from tbl_name where key_col LIKE “%Patrick%”;
\nmysql> select * from tbl_name where key_col LIKE other_col;<\/p>\n
\uccab\ubc88\uc9f8 \ubb38\uc7a5\uc5d0\uc11c LIKE \uac12\uc740 \uc640\uc77c\ub4dc\uce74\ub4dc \ubb38\uc790\ub85c \uc2dc\uc791\ud558\uace0 \uc788\ub2e4. \ub450 \ubc88\uc9f8 \ubb38\uc7a5\uc5d0\uc11c\ub294 LIKE
\n\uac12\uc774 \uc0c1\uc218\uac00 \uc544\ub2c8\ub2e4.<\/p>\n
5) WHERE \ubb38\uc5d0\uc11c \ucd5c\uc801\ud654\ud558\uae30<\/p>\n
\uc77c\ubc18\uc801\uc73c\ub85c \ub290\ub9b0 SELECT … WHERE \ubb38\uc744 \ube60\ub974\uac8c \ud558\ub824\uba74 \uac00\uc7a5 \uba3c\uc800 \ud655\uc778\ud574\uc57c \ud560 \uac83\uc774 \uc778
\n\ub371\uc2a4 \ucd94\uac00 \ubb38\uc81c\uc774\ub2e4. \ub2e4\ub978 \ud14c\uc774\ube14\uc0ac\uc774\uc5d0\uc11c \ubaa8\ub4e0 \ub808\ud37c\ub7f0\uc2a4\ub294 \uc77c\ubc18\uc801\uc73c\ub85c \uc778\ub371\uc2a4\uc5d0 \uc758\ud574 \uc218\ud589\ub41c\ub2e4. SELECT \ubb38\uc5d0\uc11c \uc5b4\ub5a4 \uc778\ub371\uc2a4\ub97c \uc0ac\uc6a9\ud558\ub294\uc9c0 \uacb0\uc815\ud558\uae30 \uc704\ud574 EXPLAIN \uba85\ub839\uc744 \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4. <\/p>\n
mysql\uc5d0\uc11c \uc218\ud589\ud558\ub294 \ucd5c\uc801\ud654\ub294 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n
– \ubd88\ud544\uc694\ud55c \uc0bd\uc785\uc5b4 \uc81c\uac70<\/p>\n
((a AND b) AND c OR (((a AND b) AND (c AND d))))
\n-> (a AND b ANDc) OR (a AND b AND c AND d)<\/p>\n
-\uc0c1\uc218 \ud3f4\ub529(folding)<\/p>\n
(a
\n-> b>5 AND b=c AND a=5<\/p>\n
– \uc0c1\uc218 \uc870\uac74 \uc81c\uac70(\uc0c1\uc218 \ud3f4\ub529\ub54c\ubb38\uc5d0 \ud544\uc694)<\/p>\n
(B>=5 AND&nbs <\/p>\n","protected":false},"excerpt":{"rendered":"
mysql\uc758 \ucd5c\ub300 \uc131\ub2a5 \ud5a5\uc0c1 \ubc29\ubc95 1) \ubc84\ud37c \ud06c\uae30 \uc870\uc815 mysqld \uc11c\ubc84\uac00 \uc0ac\uc6a9\ud558\ub294 \uae30\ubcf8 \ubc84\ud37c \ud06c\uae30\ub294 \ub2e4\uc74c\uc758 \uba85\ub839\uc73c\ub85c \uc54c \uc218 \uc788\ub2e4. shell> mysqld –help \uc774 \uba85\ub839\uc740 \ubaa8\ub4e0 mysqld \uc635\uc158\uc758 \ubaa9\ub85d\uacfc \uc124\uc815 \ubcc0\uc218\ub97c \ubcf4\uc5ec\uc900\ub2e4. \ucd9c\ub825\ub418\ub294 \ub0b4\uc6a9\uc740 \uae30\ubcf8\uac12\uc744 \ud3ec\ud568\ud558\uace0 \uc788\uc73c\uba70 \ub2e4\uc74c\uacfc \ube44\uc2b7\ud558\ub2e4. Possible variables for option –set-variable (-O) are: back_log current value: 5 connect_timeout current value: 5 join_buffer … \uacc4\uc18d \uc77d\uae30 “[mysql] mysql\ud29c\ub2dd”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1379","post","type-post","status-publish","format-standard","hentry","category-tip"],"_links":{"self":[{"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=\/wp\/v2\/posts\/1379","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1379"}],"version-history":[{"count":0,"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=\/wp\/v2\/posts\/1379\/revisions"}],"wp:attachment":[{"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1379"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1379"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bluesoul.pe.kr\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1379"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}