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public class SimpleStore {
private Map sessions = Collections.synchronizedMap(new HashMap());
synchronized public void remove(String sessionID) { //A1
sessions.put(sessionID, ""); //A2
sessions.remove(sessionID);
System.out.println("remove " + sessionID);
}
public void commit(Map attrs, String sessionID, StatusHolder statusHolder) {
System.out.println("commit " + sessionID);
synchronized (sessions) { //B1
remove(sessionID); // B2
}
}
}
涓婇潰浠ｇ爜涓細private Map sessions = Collections.synchronizedMap(new HashMap());
synchronized public void remove(String sessionID) { //A1
sessions.put(sessionID, ""); //A2
sessions.remove(sessionID);
System.out.println("remove " + sessionID);
}
public void commit(Map attrs, String sessionID, StatusHolder statusHolder) {
System.out.println("commit " + sessionID);
synchronized (sessions) { //B1
remove(sessionID); // B2
}
}
}
private Map sessions = Collections.synchronizedMap(new HashMap());
灝唖essions榪欎釜map鐢蟲槑涓虹嚎紼嬪畨鍏ㄧ殑map,鍒欐搷浣渕ap涓殑浠諱綍鏂規硶鏃訛紝閮戒細鍔犻攣錛屽茍涓斾細閿佷綇sessions瀵硅薄銆?/span> 榪欒浠ｇ爜錛屽垯鍦ㄥ閮ㄧ嚎紼嬭闂畆emove鏂規硶鏃朵細閿佷綇SimpleStore榪欎釜瀵硅薄銆?br /> synchronized public void remove(String sessionID);
鍙互鐪嬪埌錛岀洰鍓嶅湪鍚屼竴涓被鎴栬呮柟娉曚腑錛屾湁涓ゆ妸閿侊紝騫朵笖閿佸璞′笉鏄悓涓涓紝閭ｄ笅闈㈡垜浠湅鐪嬬嚎紼嬫槸鎬庝箞琚閿佷綇鐨勶細
1, 鍋囪A綰跨▼鍏堣皟鐢╮emove鏂規硶錛屽垯榪欐椂浼氭妸simpleStore緇欓攣浣忥紝鐒跺悗鎵цsessions.put(sessionID, “”)鐨勬椂鍊欙紝浼氬皾璇曢攣浣弒essions
2, 鍚屾椂B綰跨▼璋冪敤commit鏂規硶錛屽湪 synchronized (sessions) 鏃訛紝浼氬厛閿佷綇sessions瀵硅薄錛屽茍涓斿湪璋冪敤鎺ヤ笅鏉ョ殑remove()璇曪紝浼氬皾璇曢攣浣?nbsp; SimpleStore瀵硅薄錛岃嚦姝わ紝綰跨▼A鍜岀嚎紼婤緇堜簬鎴愬姛瀹屾垚姝婚攣銆?/span>
鎵浠ュ湪浣跨敤澶氱嚎紼嬫椂涓瀹氳鐗瑰埆娉ㄦ剰錛屼嬌鐢ㄩ攣涓瀹氳娉ㄦ剰浣犵殑閿佸璞℃槸鍚︿竴鑷淬傝涓嶇劧灝辨湁鍙兘姝婚攣浜唦
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alter database flashback off
涓嶅緩璁湪姝ｅ紡鐜浣跨敤榪欑鏂規硶錛屽鏋滃湪寮鍙戠幆澧冨垯鍙互灝濊瘯浣跨敤榪欑鏂規硶銆傚洜涓哄繀绔熷紑鍙戠幆澧冨浜庢暟鎹殑鎭㈠娌℃湁浠涔堣姹傦紝娌℃湁澶氬ぇ鐨勬鐜囩敤鍒伴棯鍥炪?/span>絎簩縐嶈В鍐蟲柟寮忥細灝嗛棯鍥炴棩蹇楁枃浠剁殑鏈澶у閲忚皟楂橈紝鍙互浣跨敤濡備笅璇彞
alter system set DB_RECOVERY_FILE_DEST_SIZE=20g
鍙互閫氳繃濡傛灉涓嬭鍙ユ煡鐪嬬洰鍓嶉棯鍥炴枃浠剁殑澶у皬浠ュ強浣跨敤鎯呭喌select * from v$recovery_file_dest;
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