常連

注目の的

社会貢献

質問力

自己紹介

###質問したいこと
Oracle Database 11gをWindows 2008 R2 Standard x64の上で動かしています。
一時表領域がどれだけ利用されているかを確認したところ、
使用率が100%となっていました。※表1

表1. 一時表領域の使用率
> ![一時表領域の使用率](6991515dda2f7c72db654c8f46889ee2.png)
> こちらのSQLを実行して結果を取得しました
> http://d.hatena.ne.jp/gonsuke777/comment/20111117/1321463750

1. 一時表領域の使用率が100%になると発生する問題はありますか？
1. 一時表領域の使用率が100%になるとSYSTEMテーブルなどのテーブルがかわりに利用されますか？
2. 今後運用するにあたり一時表領域を拡張する必要性はありまか？

###補足情報
- 表領域の自動拡張はOFFにしています。
- その他テーブルの使用率です
> ![その他テーブルの使用率](6ab43285a825130f7101673803cfd42b.png)
> こちらのSQLを実行して結果を取得しました
> http://www.sql-dbtips.com/tablespace/used/

Oracle Database 11gの一時表領域の使用率100%になった

AWSのRDSにMySQLをインストールして
サーブレットでMySQLに接続したいのですが、
できない状況です。

環境はMac OS X 10.9でeclipse Luna 4.4を用いて開発をおこなっており、
localhostからRDSのMySQLへ接続しようとしています。

その時のサーブレットのコードは以下のとおりです。
```java
private Connection connect = null;
	private String url =
			"jdbc:mysql://インタンス名.cvwnt4utponq.ap-northeast-1.rds.amazonaws.com:3306/データベース名";
	private String user = "ユーザー名"; // ユーザー名
	private String password = "パスワード"; // パスワード
	
	// SQLに接続するメソッド
		public void connect() throws Exception {
			Class.forName("com.mysql.jdbc.Driver");
			// .newInstance()
			connect = DriverManager.getConnection(url, user, password);
		}
		
		// SQLを切断するメソッド
		public void close() {
			try {
				connect.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
```
---
追記
```
28-Jul-2015 00:18:30.029 INFO [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.HostConfig.undeploy Undeploying context [/EGlunch]
28-Jul-2015 00:18:30.041 WARNING [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [EGlunch] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
28-Jul-2015 00:18:30.050 WARNING [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [EGlunch] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 java.lang.Object.wait(Native Method)
 java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
 com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)
28-Jul-2015 00:18:30.057 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/usr/share/tomcat8/work/Catalina/localhost/EGlunch] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.058 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.delete [/usr/share/tomcat8/work/Catalina/localhost/EGlunch] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.058 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/META-INF] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.058 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/fb] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.059 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/mail] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.059 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/search] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.059 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/dao] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.060 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/offer] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.060 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/beans] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.061 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/tomorrowlunch] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.063 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/message] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.063 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes/profile] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.064 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/classes] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.064 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF/lib] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.071 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/WEB-INF] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.071 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/js] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.072 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/css] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.072 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/fonts] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.073 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/image/images/images] could not be completely deleted. The presence of the remaining files may cause problems
28-Jul-2015 00:18:30.074 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.ExpandWar.deleteDir [/var/lib/tomcat8/webapps/EGlunch/image/images] could not be completely deleted. The presence of the remaining files may cause problems
・・・

28-Jul-2015 00:18:30.108 SEVERE [localhost-startStop-2] org.apache.catalina.startup.ContextConfig.beforeStart Exception fixing docBase for context [/EGlunch]
 java.io.IOException: [/var/lib/tomcat8/webapps/EGlunch] could not be completely deleted. The presence of the remaining files may cause problems
	at org.apache.catalina.startup.ExpandWar.expand(ExpandWar.java:109)
	at org.apache.catalina.startup.ContextConfig.fixDocBase(ContextConfig.java:618)
	at org.apache.catalina.startup.ContextConfig.beforeStart(ContextConfig.java:744)
	at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:307)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
	at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:402)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
	at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:945)
	at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1768)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
```
以後もエラーが続きます。

サーブレットでAWSのMySQLに接続できません

「パーフェクトjava」という書籍内で記述されている、クラス内でのthis参照について質問があります。

クラスのメソッド内でthis参照を行うと、参照先のオブジェクトを参照するが、コンストラクタ、初期化ブロック、フィールド宣言の初期化ではthis参照は、生成中のオブジェクトを参照すると書かれていました。

ここで質問です。
まず、参照先のオブジェクトと生成中のオブジェクトにはどのような違いがあるのでしょうか。また、this参照において、区別する理由は何かあるのでしょうか。
最後に、明確にどこからどこまでが生成中のオブジェクトで、どこからどこまでが生成されたオブジェクトなのでしょうか。

ご教授お願いいたします。