聽聽 聽 浜嬪姟鏄簲鐢ㄧ▼搴忎腑涓緋誨垪涓ュ瘑鐨勬搷浣滐紝鎵鏈夋搷浣滃繀欏繪垚鍔熷畬鎴愶紝鍚﹀垯鍦ㄦ瘡涓搷浣滀腑鎵浣滅殑鎵鏈夋洿鏀歸兘浼氳鎾ゆ秷銆備篃灝辨槸浜嬪姟鍏鋒湁鍘熷瓙鎬э紝涓涓簨鍔′腑鐨勪竴緋誨垪鐨勬搷浣滆涔堝叏閮ㄦ垚鍔燂紝瑕佷箞涓涓兘涓嶅仛銆?/span>
聽聽 浜嬪姟鐨勭粨鏉熸湁涓ょ錛屽綋浜嬪姟涓殑鎵浠ユ楠ゅ叏閮ㄦ垚鍔熸墽琛屾椂錛屼簨鍔℃彁浜ゃ傚鏋滃叾涓竴涓楠ゅけ璐ワ紝灝嗗彂鐢熷洖婊氭搷浣滐紝鎾ゆ秷鎾ゆ秷涔嬪墠鍒頒簨鍔″紑濮嬫椂鐨勬墍浠ユ搷浣溿?/span>
浜岋紟浜嬪姟鐨?/span>
ACID
浜嬪姟鍏鋒湁鍥涗釜鐗瑰緛錛氬師瀛愭э紙 Atomicity 錛夈佷竴鑷存э紙 Consistency 錛夈侀殧紱繪э紙 Isolation 錛夊拰鎸佺畫鎬э紙 Durability 錛夈傝繖鍥涗釜鐗規х畝縐頒負 ACID 鐗規с?/span>
1 銆佸師瀛愭?/span>
聽聽聽
浜嬪姟鏄暟鎹簱鐨勯昏緫宸ヤ綔鍗曚綅錛屼簨鍔′腑鍖呭惈鐨勫悇鎿嶄綔瑕佷箞閮藉仛錛岃涔堥兘涓嶅仛
2 銆佷竴鑷存?/span>
聽聽聽聽聽 浜嬪姟鎵ц鐨勭粨鏋滃繀欏繪槸浣挎暟鎹簱浠庝竴涓竴鑷存х姸鎬佸彉鍒板彟涓涓竴鑷存х姸鎬併傚洜姝ゅ綋鏁版嵁搴撳彧鍖呭惈鎴愬姛浜嬪姟鎻愪氦鐨勭粨鏋滄椂錛屽氨璇存暟鎹簱澶勪簬涓鑷存х姸鎬併傚鏋滄暟鎹簱緋葷粺榪愯涓彂鐢熸晠闅滐紝鏈変簺浜嬪姟灝氭湭瀹屾垚灝辮榪腑鏂紝榪欎簺鏈畬鎴愪簨鍔″鏁版嵁搴撴墍鍋氱殑淇敼鏈変竴閮ㄥ垎宸插啓鍏ョ墿鐞嗘暟鎹簱錛岃繖鏃舵暟鎹簱灝卞浜庝竴縐嶄笉姝ｇ‘鐨勭姸鎬侊紝鎴栬呰鏄笉涓鑷寸殑鐘舵併?/span> 聽
3 銆侀殧紱繪?/span>
聽聽聽
涓涓簨鍔＄殑鎵ц涓嶈兘鍏跺畠浜嬪姟騫叉壈銆傚嵆涓涓簨鍔″唴閮ㄧ殑鎿嶄綔鍙婁嬌鐢ㄧ殑鏁版嵁瀵瑰叾瀹冨茍鍙戜簨鍔℃槸闅旂鐨勶紝騫跺彂鎵ц鐨勫悇涓簨鍔′箣闂翠笉鑳戒簰鐩稿共鎵般?/span>
4 銆佹寔緇?/span>
聽聽 涔熺О姘鎬箙鎬э紝鎸囦竴涓簨鍔′竴鏃︽彁浜わ紝瀹冨鏁版嵁搴撲腑鐨勬暟鎹殑鏀瑰彉灝卞簲璇ユ槸姘鎬箙鎬х殑銆傛帴涓嬫潵鐨勫叾瀹冩搷浣滄垨鏁呴殰涓嶅簲璇ュ鍏舵墽琛岀粨鏋滄湁浠諱綍褰卞搷銆?/span>
浜岋紟浜嬪姟鐨勫睘鎬?/span>
涓涓簨鍔＄殑灞炴ф帶鍒朵簡浜嬪姟鐨勪嬌鐢ㄨ寖鍥淬?/span> EJB 銆?/span> Spring 浠ュ強.net涓嬬殑浜嬪姟灞炴ч兘寰堢被浼肩殑錛?/span> 浜嬪姟灞炴ф湁濡備笅鍑犵錛?/span>
Required:
濡傛灉鍦ㄤ竴涓簨鍔′腑璋冪敤錛屽氨鎶婅鏂規硶鍔犲埌姝や簨鍔′腑鏉?/span>
濡傛灉榪樻病鏈夊惎鍔ㄤ簨鍔★紝灝卞惎鍔ㄤ竴涓柊浜嬪姟
RequiredNew:
涓嶇褰撳墠鏈夋病鏈変簨鍔★紝閮戒細鍚姩涓涓柊浜嬪姟錛屽鏋滃綋鍓嶆湁浜嬪姟錛屼細琚寕璧風洿鍒版柟娉曠粨鏉熴?/span>
NotSupported:
涓嶈兘鍦ㄤ簨鍔′腑鎵ц姝ゆ柟娉曘傚鏋滄湁浜嬪姟錛屽皢浼氳鎸傝搗鐩村埌鏂規硶緇撴潫銆?/span>
Supports:
濡傛灉褰撳墠鏈変簨鍔★紝姝ゆ柟娉曚細鍔犲埌褰撳墠浜嬪姟錛屽鏋滄病鏈夛紝瀹瑰櫒涔熶笉浼氬惎鍔ㄦ柊浜嬪姟銆?/span>
Mandatory:
蹇呴』鍦ㄤ簨鍔′腑璋冪敤姝ゆ柟娉曪紝鍚﹀垯鎶涘嚭寮傚父銆?br />
Never:
蹇呴』涓嶅湪浜嬪姟涓皟鐢ㄦ鏂規硶錛屽惁鍒欐姏鍑哄紓甯搞?/span>
涓夛紟浜嬪姟鐨勫洖婊?/span>
CMT 鍦ㄤ互涓嬩袱涓儏鍐典笅錛屼簨鍔″皢鍥炴粴銆傜涓錛屽鏋滀駭鐢熶竴涓郴緇熷紓甯革紝瀹瑰櫒灝嗚嚜鍔ㄥ洖婊氳浜嬪姟銆傜浜岋紝閫氳繃璋冪敤 EJBContext 鎺ュ彛 SetRollbackOnly 鏂規硶錛?/span> Bean 鏂規硶閫氱煡瀹瑰櫒鍥炴粴璇ヤ簨鍔°傚鏋?/span> Bean 鎶涘嚭涓涓簲鐢ㄥ紓甯革紝浜嬪姟灝嗕笉浼氳嚜鍔ㄥ洖婊氾紝浣嗗彲浠ヨ皟鐢?/span> SetRollbackOnly 鍥炴粴銆?/span>
鍥涳紟浜嬪姟瓚呮椂
瀵逛簬 EJB 涓殑瀹瑰櫒綆＄悊浜嬪姟錛屼簨鍔¤秴鏃墮棿闅旀槸閫氳繃璁劇疆 default.properties 鏂囦歡涓?/span> ransaction.timeout 灞炴х殑鍊兼潵紜畾鐨勶紝璇ユ枃浠跺湪 J2EE SDK 瀹夎鐩綍鐨?/span> config 瀛愮洰褰曚笅銆傚涓嬩緥灝嗕簨鍔¤秴鏃墮棿闅旇緗負 5 縐掗挓錛?/span> transaction.timeout=5 錛岃繖鏍鳳紝褰撲簨鍔″湪 5 縐掗挓鍐呰繕娌℃湁瀹屾垚錛屽鍣ㄥ皢鍥炴粴璇ヤ簨鍔°?/span>
J2EE SDK 瀹夎鍚庯紝瓚呮椂闂撮殧鐨勭己鐪佸間負 0 錛岃〃紺轟笉璁＄畻瓚呮椂錛屾棤璁轟簨鍔℃墽琛屽闀挎椂闂達紝闄ら潪寮傚父鍑洪敊鍥炴粴錛屼竴鐩寸瓑寰呬簨鍔″畬鎴愩?/span>
鍙湁浣跨敤瀹瑰櫒綆＄悊浜嬪姟鐨勪紒涓?/span> Bean 鎵嶄細鍙楀埌 transaction.timeout 灞炴у肩殑褰卞搷銆?/span> Bean 綆＄悊鐨?/span> JTA 浜嬪姟浣跨敤 UserTransaction 鎺ュ彛鐨?/span> setTransactionTimeout 鏂規硶鏉ヨ緗簨鍔¤秴鏃墮棿闅斻?/span>
浜旓紟闅旂綰у埆
顥ヮ棩 浜嬪姟涓嶄粎淇濊瘉浜嬪姟鐣岄檺鍐呯殑鏁版嵁搴撴搷浣滃叏閮ㄥ畬鎴愶紙鎴栧洖婊氾級鍚屾椂榪橀殧紱繪暟鎹簱鏇存柊璇彞銆傞殧紱葷駭鍒弿榪拌淇敼鐨勬暟鎹鍏朵粬浜嬬墿鐨勫彲瑙佸害銆傞殧紱葷駭鍒殑鎺у埗浼氳窡鍏蜂綋鐨?/span> DBMS 鍘傚晢涓嶅悓鑰屼笉鍚屻?/span>
聽聽聽 聽 闅旂綰у埆涓庡茍鍙戞ф槸浜掍負鐭涚浘鐨勶細闅旂紼嬪害瓚婇珮錛屾暟鎹簱鐨勫茍鍙戞ц秺宸紱闅旂紼嬪害瓚婁綆錛屾暟鎹簱鐨勫茍鍙戞ц秺濂姐?/span>
閫氳繃涓浜涚幇璞★紝鍙互鍙嶆槧鍑洪殧紱葷駭鍒殑鏁堟灉銆傝繖浜涚幇璞℃湁錛?/span>
l聽聽聽聽聽聽聽聽 鏇存柊涓㈠け錛?/span> lost update 錛夛細褰撶郴緇熷厑璁鎬袱涓簨鍔″悓鏃舵洿鏂板悓涓鏁版嵁鏄紝鍙戠敓鏇存柊涓㈠け銆?/span>
l聽聽聽聽聽聽聽聽 鑴忚錛?/span> dirty read 錛夛細褰撲竴涓簨鍔¤鍙栧彟涓涓簨鍔″皻鏈彁浜ょ殑淇敼鏃訛紝浜х敓鑴忚銆?/span>
l聽聽聽聽聽聽聽聽 闈為噸澶嶈錛?/span> nonrepeatable read 錛夛細浜嬪姟澶氭璇誨彇鍚屼竴琛屼腑鐨勬暟鎹?/strong>鍗村緱鍒頒笉鍚屾暟鍊兼椂銆備緥濡傦細浜嬪姟1璇誨彇浜嗕竴琛屾暟鎹紝鑰屼簨鍔?鏀瑰彉鎴栧垹闄や簡閭ｄ簺琛屽茍鎻愪氦浜嗕慨鏀廣傚鏋滀簨鍔?鍐嶆璇誨彇浜嗛偅涓琛岋紝閭ｄ箞錛屼簨鍔?灝卞緱鍒頒簡涓嶅悓鐨勬暟鍊鹼紙琚洿鏂版垨鍒犻櫎錛夈?br />
l聽聽聽聽聽聽聽聽 騫誨儚璇伙紙 phantom read 錛夛細涓琛屾暟鎹弧瓚蟲悳绱㈣鍒欙紝鍗村湪寮濮嬫病鏈夎鐪嬪埌銆備緥濡傦細浜嬪姟1璇誨彇浜嗕竴緋誨垪婊¤凍鎼滅儲瑙勫垯鐨勮錛岃屼簨鍔?鎻掑叆鎴栧垹闄や簡涓涓弧瓚充簨鍔?鎼滅儲瑙勫垯鐨勮銆傚鏋滀簨鍔?鍐嶆鎵ц鏌ヨ璇彞錛屽氨浼氬緱鍒頒笉鍚岀殑涓緋誨垪琛屻?/span>
SQL-99 鏍囧噯瀹氫箟浜嗕笅鍒楅殧紱葷駭鍒細
l聽聽聽聽聽聽聽聽 鏈彁浜よ錛?/span> read uncommitted 錛夛紙闅旂浜嬪姟鐨勬渶浣庣駭鍒紝鍙兘淇濊瘉涓嶈鍙栫墿鐞嗕笂鎹熷潖鐨勬暟鎹級
l聽聽聽聽聽聽聽聽 宸叉彁浜よ錛?/span> read committed 錛夛紙鏁版嵁搴撳紩鎿?/span> 聽 鐨勯粯璁ょ駭鍒級褰撲竴涓簨鍔¤繍琛屽湪榪欎釜闅旂綰у埆鏃訛紝 涓涓?/span> SELECT 鏌ヨ鍙兘鐪嬪埌鏌ヨ寮濮嬩箣鍓嶆彁浜ょ殑鏁版嵁錛岃屾案榪?/span> 鏃犳硶鐪嬪埌鏈彁浜ょ殑鏁版嵁錛屾垨鑰呮槸鍦ㄦ煡璇㈡墽琛屾椂鍏朵粬騫惰鐨勪簨鍔℃彁浜ゅ仛鐨勬敼鍙樸?/span>
l聽聽聽聽聽聽聽聽 鍙噸澶嶈錛?/span> repeatable read 錛夛紝涓嶄細鑴忚鍜岄潪閲嶅璇伙紝鍙兘鍙戠敓騫誨儚璇?/span>
l聽聽聽聽聽聽聽聽
鍙覆琛屽寲錛?/span>
serializable
錛夛紙闅旂浜嬪姟鐨勬渶楂樼駭鍒紝浜嬪姟涔嬮棿瀹屽叏闅旂錛?br />
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽
ANSI/ISO SQL
闅旂綰у埆
|
闅旂綰у埆 |
鑴忚錛?span lang="EN-US">DirtyRead錛?/span>
|
涓嶅彲閲嶅鐨勮錛?span lang="EN-US">Non-Repeatable Read錛?/span>
|
聽
騫誨儚
璇誨彇錛?span lang="EN-US">Phantom Read錛?/span>
|
|
鏈彁浜よ
錛?span lang="EN-US">Read uncommitted錛? |
鍙兘 |
鍙兘 |
鍙兘 |
|
宸叉彁浜よ
錛?span lang="EN-US">Read committed錛? |
涓嶅彲鑳? |
鍙兘 |
鍙兘 |
|
鍙噸澶嶈錛?span lang="EN-US">Repeatable read錛? |
涓嶅彲鑳? |
涓嶅彲鑳? |
鍙兘 |
|
鍙覆琛屽寲錛?span lang="EN-US">Serializable 錛? |
涓嶅彲鑳? |
涓嶅彲鑳? |
涓嶅彲鑳? |
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