diff --git a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditDao.java b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditDao.java
index c56c7cf1b..ad80954b2 100644
--- a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditDao.java
+++ b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditDao.java
@@ -134,7 +134,7 @@ public class PostgreSqlAuditDao implements AuditDao {
 		try (PreparedStatement statement = this.tx.getConnection().prepareStatement(sql)) {
 			try (ResultSet result = statement.executeQuery()) {
 				while (result.next()) {
-					keySet.add(result.getString(ELEMENT_TYPE)); //$NON-NLS-1$
+					keySet.add(result.getString(ELEMENT_TYPE));
 				}
 			}
 		} catch (SQLException e) {
diff --git a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditQueryVisitor.java b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditQueryVisitor.java
index c43d91d48..379c40407 100644
--- a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditQueryVisitor.java
+++ b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlAuditQueryVisitor.java
@@ -58,13 +58,13 @@ public class PostgreSqlAuditQueryVisitor implements AuditQueryVisitor {
 	}
 
 	public String getSql() {
-		if (sqlAsString != null)
-			return sqlAsString;
+		if (this.sqlAsString != null)
+			return this.sqlAsString;
 
 		this.sql.append("\nwhere\n");
 		this.sql.append(this.sb.toString());
-		sqlAsString = this.sql.toString();
-		return sqlAsString;
+		this.sqlAsString = this.sql.toString();
+		return this.sqlAsString;
 	}
 
 	@Override
@@ -120,21 +120,21 @@ public class PostgreSqlAuditQueryVisitor implements AuditQueryVisitor {
 			ensureAnd();
 			this.sb.append(this.indent);
 			if (accessTypes.length == 1) {
-				sb.append(PostgreSqlAuditDao.ACCESS_TYPE + " = ?");
-				sb.append(PostgreSqlAuditDao.ACCESS_TYPE_TYPE);
-				sb.append("\n");
+				this.sb.append(PostgreSqlAuditDao.ACCESS_TYPE + " = ?");
+				this.sb.append(PostgreSqlAuditDao.ACCESS_TYPE_TYPE);
+				this.sb.append("\n");
 				this.values.add(accessTypes[0].name());
 			} else {
-				sb.append(PostgreSqlAuditDao.ACCESS_TYPE + " in (");
+				this.sb.append(PostgreSqlAuditDao.ACCESS_TYPE + " in (");
 				for (int i = 0; i < accessTypes.length; i++) {
-					sb.append("?");
-					sb.append(PostgreSqlAuditDao.ACCESS_TYPE_TYPE);
-					values.add(accessTypes[i].name());
+					this.sb.append("?");
+					this.sb.append(PostgreSqlAuditDao.ACCESS_TYPE_TYPE);
+					this.values.add(accessTypes[i].name());
 					if (i < accessTypes.length - 1)
-						sb.append(", ");
+						this.sb.append(", ");
 				}
-				sb.append(" )\n");
-				sb.append("\n");
+				this.sb.append(" )\n");
+				this.sb.append("\n");
 			}
 		}
 	}
diff --git a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlOrderQueryVisitor.java b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlOrderQueryVisitor.java
index 687ac1331..40050292a 100644
--- a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlOrderQueryVisitor.java
+++ b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlOrderQueryVisitor.java
@@ -32,10 +32,12 @@ public class PostgreSqlOrderQueryVisitor extends PostgreSqlQueryVisitor implemen
 		super(fields);
 	}
 
+	@Override
 	protected String getClassName() {
 		return Tags.ORDER;
 	}
 
+	@Override
 	protected String getTableName() {
 		return PostgreSqlOrderDao.ORDERS;
 	}
@@ -47,8 +49,8 @@ public class PostgreSqlOrderQueryVisitor extends PostgreSqlQueryVisitor implemen
 
 	@Override
 	public void visit(StateSelection selection) {
-		sb.append(indent);
-		sb.append("state = ?::order_state\n");
-		values.add(selection.getState().name());
+		this.sb.append(this.indent);
+		this.sb.append("state = ?::order_state\n");
+		this.values.add(selection.getState().name());
 	}
 }
diff --git a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlQueryVisitor.java b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlQueryVisitor.java
index b552746e6..6051c7f53 100644
--- a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlQueryVisitor.java
+++ b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlQueryVisitor.java
@@ -75,23 +75,23 @@ public abstract class PostgreSqlQueryVisitor implements StrolchRootElementSelect
 	}
 
 	public String getSql() {
-		if (sqlAsString != null)
-			return sqlAsString;
+		if (this.sqlAsString != null)
+			return this.sqlAsString;
 
 		this.sql.append("\nwhere\n");
 		this.sql.append(this.indent);
 
 		if (this.any) {
 			this.sql.append("type = ?");
-			sqlAsString = this.sql.toString();
-			return sqlAsString;
+			this.sqlAsString = this.sql.toString();
+			return this.sqlAsString;
 		}
 
 		this.sql.append("type = ? and\n");
 
 		this.sql.append(this.sb.toString());
-		sqlAsString = this.sql.toString();
-		return sqlAsString;
+		this.sqlAsString = this.sql.toString();
+		return this.sqlAsString;
 	}
 
 	/**
@@ -235,42 +235,42 @@ public abstract class PostgreSqlQueryVisitor implements StrolchRootElementSelect
 		xpath = xpath.replace("${bagKey}", selection.getBagKey());
 		xpath = xpath.replace("${paramKey}", selection.getParamKey());
 
-		sb.append(this.indent);
-		sb.append("id in (\n");
-		sb.append(this.indent);
-		sb.append("  SELECT id\n");
-		sb.append(this.indent);
-		sb.append("  FROM (\n");
-		sb.append(this.indent);
-		sb.append("    SELECT id, UNNEST(");
-		sb.append(xpath);
-		sb.append("\n");
-		sb.append(this.indent);
-		sb.append("from ");
-		sb.append(getTableName());
-		sb.append("\n");
-		sb.append(this.indent);
-		sb.append(") AS alias\n");
-		sb.append(this.indent);
-		sb.append("WHERE ");
+		this.sb.append(this.indent);
+		this.sb.append("id in (\n");
+		this.sb.append(this.indent);
+		this.sb.append("  SELECT id\n");
+		this.sb.append(this.indent);
+		this.sb.append("  FROM (\n");
+		this.sb.append(this.indent);
+		this.sb.append("    SELECT id, UNNEST(");
+		this.sb.append(xpath);
+		this.sb.append("\n");
+		this.sb.append(this.indent);
+		this.sb.append("from ");
+		this.sb.append(getTableName());
+		this.sb.append("\n");
+		this.sb.append(this.indent);
+		this.sb.append(") AS alias\n");
+		this.sb.append(this.indent);
+		this.sb.append("WHERE ");
 
 		if (selection.getMatchMode().isEquals()) {
 			if (selection.getMatchMode().isCaseSensitve()) {
-				sb.append("content = ?\n");
+				this.sb.append("content = ?\n");
 			} else {
-				sb.append("content ILIKE ?\n");
+				this.sb.append("content ILIKE ?\n");
 			}
 		} else {
 			value = "%" + value + "%";
 			if (selection.getMatchMode().isCaseSensitve()) {
-				sb.append("content LIKE ?\n");
+				this.sb.append("content LIKE ?\n");
 			} else {
-				sb.append("content ILIKE ?\n");
+				this.sb.append("content ILIKE ?\n");
 			}
 		}
 
-		sb.append(this.indent);
-		sb.append(")\n");
+		this.sb.append(this.indent);
+		this.sb.append(")\n");
 
 		this.values.add(value);
 	}
diff --git a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlResourceQueryVisitor.java b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlResourceQueryVisitor.java
index 349641144..4a07fc09f 100644
--- a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlResourceQueryVisitor.java
+++ b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlResourceQueryVisitor.java
@@ -30,10 +30,12 @@ public class PostgreSqlResourceQueryVisitor extends PostgreSqlQueryVisitor imple
 		super(fields);
 	}
 
+	@Override
 	protected String getClassName() {
 		return Tags.RESOURCE;
 	}
 
+	@Override
 	protected String getTableName() {
 		return PostgreSqlResourceDao.RESOURCES;
 	}
diff --git a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlStrolchTransaction.java b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlStrolchTransaction.java
index 1d7a97068..9fa65c181 100644
--- a/src/main/java/li/strolch/persistence/postgresql/PostgreSqlStrolchTransaction.java
+++ b/src/main/java/li/strolch/persistence/postgresql/PostgreSqlStrolchTransaction.java
@@ -100,7 +100,7 @@ public class PostgreSqlStrolchTransaction extends AbstractTransaction {
 	public AuditDao getAuditDao() {
 		if (this.auditDao == null)
 			this.auditDao = new PostgreSqlAuditDao(this);
-		return (AuditDao) this.auditDao;
+		return this.auditDao;
 	}
 
 	Connection getConnection() {