[Major] Extended StrolchDao with paging feature

li.strolch.agent/src/main/java/li/strolch/persistence/api/StrolchDao.java

@@ -39,19 +39,29 @@ import li.strolch.model.StrolchRootElement;
  */
 public interface StrolchDao<T extends StrolchRootElement> {
 
+	/**
+	 * Returns true if this {@link StrolchDao} supports paging, i.e. the methods with a limit and offset may be used
+	 *
+	 * @return true if this {@link StrolchDao} supports paging, i.e. the methods with a limit and offset may be used
+	 */
+	boolean supportsPaging();
+
 	/**
 	 * Returns the number of elements in the underlying persistence layer, regardless of type
 	 *
 	 * @return the number of elements in the underlying persistence layer
 	 */
-	public long querySize();
+	long querySize();
 
 	/**
-	 * Returns the number of elements in the underlying persistence layer for the given type
+	 * Returns the number of elements in the underlying persistence layer for the given type(s)
 	 *
-	 * @return the number of elements in the underlying persistence layer for the given type
+	 * @param types
+	 * 		the type(s) to query the size for
+	 *
+	 * @return the number of elements in the underlying persistence layer for the given type(s)
 	 */
-	public long querySize(String type);
+	long querySize(String... types);
 
 	/**
 	 * Queries the current list of types from the underlying persistence layer
@@ -61,20 +71,62 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public Set<String> queryTypes() throws StrolchPersistenceException;
+	Set<String> queryTypes() throws StrolchPersistenceException;
+
+	/**
+	 * Queries and returns all elements regardless of type
+	 *
+	 * @return all elements regardless of type
+	 *
+	 * @throws StrolchPersistenceException
+	 * 		if something goes wrong
+	 */
+	List<T> queryAll() throws StrolchPersistenceException;
+
+	/**
+	 * Queries and returns all elements regardless of type
+	 *
+	 * @param limit
+	 * 		the max amount, or @{@link Integer#MAX_VALUE} for all
+	 * @param offset
+	 * 		if max amount defined, then the offset to start from
+	 *
+	 * @return all elements regardless of type
+	 *
+	 * @throws StrolchPersistenceException
+	 * 		if something goes wrong
+	 */
+	List<T> queryAll(long limit, long offset) throws StrolchPersistenceException;
 
 	/**
 	 * Queries and returns all elements of the given type
 	 *
-	 * @param type
+	 * @param types
-	 * 		the type of element to return
+	 * 		the type(s) of element(s) to return
 	 *
 	 * @return all elements of the given type
 	 *
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public List<T> queryAll(String type) throws StrolchPersistenceException;
+	List<T> queryAll(String... types) throws StrolchPersistenceException;
+
+	/**
+	 * Queries and returns all elements of the given type
+	 *
+	 * @param limit
+	 * 		the max amount, or @{@link Integer#MAX_VALUE} for all
+	 * @param offset
+	 * 		if max amount defined, then the offset to start from
+	 * @param types
+	 * 		the type(s) of element(s) to return
+	 *
+	 * @return all elements of the given type
+	 *
+	 * @throws StrolchPersistenceException
+	 * 		if something goes wrong
+	 */
+	List<T> queryAll(long limit, long offset, String... types) throws StrolchPersistenceException;
 
 	/**
 	 * Persists the given element. The element must not yet exist
@@ -85,7 +137,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if the element already exists
 	 */
-	public void save(T element) throws StrolchPersistenceException;
+	void save(T element) throws StrolchPersistenceException;
 
 	/**
 	 * Persists the given list of elements. None of the elements may already exists
@@ -96,7 +148,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if any of the elements already exist
 	 */
-	public void saveAll(List<T> elements) throws StrolchPersistenceException;
+	void saveAll(List<T> elements) throws StrolchPersistenceException;
 
 	/**
 	 * Updates the given element. The element must already exist
@@ -107,7 +159,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if the element does not exist
 	 */
-	public void update(T element) throws StrolchPersistenceException;
+	void update(T element) throws StrolchPersistenceException;
 
 	/**
 	 * Updates the given list of elements. Each element must already exist
@@ -118,7 +170,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if any of the elements do not exist
 	 */
-	public void updateAll(List<T> elements) throws StrolchPersistenceException;
+	void updateAll(List<T> elements) throws StrolchPersistenceException;
 
 	/**
 	 * <p>
@@ -136,7 +188,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if the element does not exist
 	 */
-	public void remove(T element) throws StrolchPersistenceException;
+	void remove(T element) throws StrolchPersistenceException;
 
 	/**
 	 * <p>
@@ -154,7 +206,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if any of the elements do not exist
 	 */
-	public void removeAll(List<T> elements) throws StrolchPersistenceException;
+	void removeAll(List<T> elements) throws StrolchPersistenceException;
 
 	/**
 	 * <p>
@@ -171,7 +223,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public long removeAll() throws StrolchPersistenceException;
+	long removeAll() throws StrolchPersistenceException;
 
 	/**
 	 * <p>
@@ -191,7 +243,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public long removeAllBy(String type) throws StrolchPersistenceException;
+	long removeAllBy(String type) throws StrolchPersistenceException;
 
 	/**
 	 * <p>
@@ -214,7 +266,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public T queryBy(String type, String id, int version) throws StrolchPersistenceException;
+	T queryBy(String type, String id, int version) throws StrolchPersistenceException;
 
 	/**
 	 * Queries and returns all the versions of the element with the given type and ID
@@ -229,7 +281,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public List<T> queryVersionsFor(String type, String id) throws StrolchPersistenceException;
+	List<T> queryVersionsFor(String type, String id) throws StrolchPersistenceException;
 
 	/**
 	 * Queries and returns the latest version of the element with the given type and ID, -1 if no version available
@@ -244,7 +296,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public int queryLatestVersionFor(String type, String id) throws StrolchPersistenceException;
+	int queryLatestVersionFor(String type, String id) throws StrolchPersistenceException;
 
 	/**
 	 * Queries and returns the number of versions for the element with the given type and ID
@@ -259,17 +311,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public long queryVersionsSizeFor(String type, String id) throws StrolchPersistenceException;
+	long queryVersionsSizeFor(String type, String id) throws StrolchPersistenceException;
-
-	/**
-	 * Queries and returns all elements regardless of type
-	 *
-	 * @return all elements regardless of type
-	 *
-	 * @throws StrolchPersistenceException
-	 * 		if something goes wrong
-	 */
-	public List<T> queryAll() throws StrolchPersistenceException;
 
 	/**
 	 * <p>
@@ -288,7 +330,7 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if the element/version does not exist
 	 */
-	public void removeVersion(T element) throws StrolchPersistenceException;
+	void removeVersion(T element) throws StrolchPersistenceException;
 
 	/**
 	 * Causes the DAO to flush any actions which have not yet been sent to the underlying persistence layer
@@ -296,5 +338,5 @@ public interface StrolchDao<T extends StrolchRootElement> {
 	 * @throws StrolchPersistenceException
 	 * 		if something goes wrong
 	 */
-	public void flush() throws StrolchPersistenceException;
+	void flush() throws StrolchPersistenceException;
 }

li.strolch.persistence.postgresql/src/main/java/li/strolch/persistence/postgresql/PostgreSqlActivityDao.java

@@ -94,14 +94,7 @@ public class PostgreSqlActivityDao extends PostgresqlDao<Activity> implements Ac
 	@Override
 	protected void internalSave(final Activity activity) {
 
-		String sql;
+		String sql = getSql(insertAsXmlSqlS, insertAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = insertAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = insertAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement preparedStatement = this.connection.prepareStatement(sql)) {
 
@@ -193,14 +186,7 @@ public class PostgreSqlActivityDao extends PostgresqlDao<Activity> implements Ac
 							activity.getVersion()));
 		}
 
-		String sql;
+		String sql = getSql(updateAsXmlSqlS, updateAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = updateAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = updateAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement preparedStatement = this.connection.prepareStatement(sql)) {
 

li.strolch.persistence.postgresql/src/main/java/li/strolch/persistence/postgresql/PostgreSqlOrderDao.java

@@ -94,14 +94,7 @@ public class PostgreSqlOrderDao extends PostgresqlDao<Order> implements OrderDao
 	@Override
 	protected void internalSave(final Order order) {
 
-		String sql;
+		String sql = getSql(insertAsXmlSqlS, insertAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = insertAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = insertAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement preparedStatement = this.connection.prepareStatement(sql)) {
 
@@ -193,14 +186,7 @@ public class PostgreSqlOrderDao extends PostgresqlDao<Order> implements OrderDao
 							order.getVersion()));
 		}
 
-		String sql;
+		String sql = getSql(updateAsXmlSqlS, updateAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = updateAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = updateAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		// now we update the existing object
 		try (PreparedStatement preparedStatement = this.connection.prepareStatement(sql)) {

li.strolch.persistence.postgresql/src/main/java/li/strolch/persistence/postgresql/PostgreSqlResourceDao.java

@@ -94,14 +94,7 @@ public class PostgreSqlResourceDao extends PostgresqlDao<Resource> implements Re
 	@Override
 	protected void internalSave(final Resource resource) {
 
-		String sql;
+		String sql = getSql(insertAsXmlSqlS, insertAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = insertAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = insertAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement preparedStatement = this.connection.prepareStatement(sql)) {
 
@@ -193,14 +186,7 @@ public class PostgreSqlResourceDao extends PostgresqlDao<Resource> implements Re
 		}
 
 		// now we update the existing object
-		String sql;
+		String sql = getSql(updateAsXmlSqlS, updateAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = updateAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = updateAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement preparedStatement = this.connection.prepareStatement(sql)) {
 

li.strolch.persistence.postgresql/src/main/java/li/strolch/persistence/postgresql/PostgresqlDao.java

@@ -33,29 +33,37 @@ import org.postgresql.util.PGobject;
 import org.xml.sax.ContentHandler;
 import org.xml.sax.SAXException;
 
-@SuppressWarnings("nls")
 public abstract class PostgresqlDao<T extends StrolchRootElement> implements StrolchDao<T> {
 
 	private static final String querySizeSqlS = "select count(*) from {0} where latest = true";
-	private static final String querySizeOfTypeSqlS = "select count(*) from {0} where type = ? and latest = true";
+	private static final String querySizeOfTypeSqlS = "select count(*) from {0} where type = ANY(?) and latest = true";
 	private static final String querySizeOfElementSqlS = "select count(*) from {0} where type = ? and id = ?";
 	private static final String queryTypesSqlS = "select distinct type from {0} where latest = true";
 	private static final String queryLatestVersionNumberForSqlS = "select count(*), max(version) from {0} where type = ? and id = ?";
 	private static final String queryVersionsSizeForSqlS = "select count(*) from {0} where type = ? and id = ?";
+
+	private static final String updateLatestSqlS = "update {0} set latest = true where type = ? and id = ? and version = ?";
+
 	private static final String deleteElementSqlS = "delete from {0} where id = ?";
 	private static final String deleteVersionSqlS = "delete from {0} where type = ? and id = ? and version = ? and latest = true";
-	private static final String updateLatestSqlS = "update {0} set latest = true where type = ? and id = ? and version = ?";
 	private static final String deleteAllSqlS = "delete from {0}";
 	private static final String deleteAllByTypeSqlS = "delete from {0} where type = ?";
 
 	private static final String queryByVersionAsXmlSqlS = "select version, asxml from {0} where type = ? and id = ? and version = ?";
 	private static final String queryByVersionAsJsonSqlS = "select version, asjson from {0} where type = ? and id = ? and version = ?";
+
 	private static final String queryVersionsAsXmlForSqlS = "select asxml from {0} where type = ? and id = ? order by version";
 	private static final String queryVersionsAsJsonForSqlS = "select asjson from {0} where type = ? and id = ? order by version";
+
 	private static final String queryAllAsXmlSqlS = "select id, type, asxml from {0} where latest = true";
+	private static final String queryAllAsXmlLimitSqlS = "select id, type, asxml from {0} where latest = true order by id limit {1} offset {2}";
 	private static final String queryAllAsJsonSqlS = "select id, type, asjson from {0} where latest = true";
-	private static final String queryAllByTypeAsXmlSqlS = "select id, asxml from {0} where type = ? and latest = true";
+	private static final String queryAllAsJsonLimitSqlS = "select id, type, asjson from {0} where latest = true order by id limit {1} offset {2}";
-	private static final String queryAllByTypeAsJsonSqlS = "select id, asjson from {0} where type = ? and latest = true";
+
+	private static final String queryAllByTypeAsXmlSqlS = "select id, type, asxml from {0} where type = ANY(?) and latest = true";
+	private static final String queryAllByTypeAsXmlLimitSqlS = "select id, type, asxml from {0} where type = ANY(?) and latest = true order by id limit {1} offset {2}";
+	private static final String queryAllByTypeAsJsonSqlS = "select id, type, asjson from {0} where type = ANY(?) and latest = true";
+	private static final String queryAllByTypeAsJsonLimitSqlS = "select id, type, asjson from {0} where type = ANY(?) and latest = true order by id limit {1} offset {2}";
 
 	protected final DataType dataType;
 	protected Connection connection;
@@ -72,6 +80,11 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 		this.commands = new ArrayList<>();
 	}
 
+	@Override
+	public boolean supportsPaging() {
+		return true;
+	}
+
 	public DataType getDataType() {
 		return this.dataType;
 	}
@@ -144,10 +157,16 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 	}
 
 	@Override
-	public long querySize(String type) {
+	public long querySize(String... types) {
+		if (types.length == 0)
+			return querySize();
+
 		String sql = MessageFormat.format(querySizeOfTypeSqlS, getTableName());
+
 		try (PreparedStatement statement = this.connection.prepareStatement(sql)) {
-			statement.setString(1, type);
+
+			Array typesArray = statement.getConnection().createArrayOf("varchar", types);
+			statement.setArray(1, typesArray);
 
 			try (ResultSet result = statement.executeQuery()) {
 				result.next();
@@ -161,9 +180,10 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 
 	@Override
 	public Set<String> queryTypes() {
-		Set<String> keySet = new HashSet<>();
 
 		String sql = MessageFormat.format(queryTypesSqlS, getTableName());
+
+		Set<String> keySet = new HashSet<>();
 		try (PreparedStatement statement = this.connection.prepareStatement(sql)) {
 
 			try (ResultSet result = statement.executeQuery()) {
@@ -182,14 +202,7 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 	@Override
 	public T queryBy(String type, String id, int versionNr) {
 
-		String sql;
+		String sql = getSql(queryByVersionAsXmlSqlS, queryByVersionAsJsonSqlS);
-		if (this.dataType == DataType.xml)
-			sql = queryByVersionAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = queryByVersionAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement statement = this.connection.prepareStatement(sql)) {
 			statement.setString(1, type);
@@ -220,17 +233,9 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 	@Override
 	public List<T> queryVersionsFor(String type, String id) {
 
+		String sql = getSql(queryVersionsAsXmlForSqlS, queryVersionsAsJsonForSqlS);
+
 		List<T> list = new ArrayList<>(1);
-
-		String sql;
-		if (this.dataType == DataType.xml)
-			sql = queryVersionsAsXmlForSqlS;
-		else if (this.dataType == DataType.json)
-			sql = queryVersionsAsJsonForSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
-
 		try (PreparedStatement statement = this.connection.prepareStatement(sql)) {
 			statement.setString(1, type);
 			statement.setString(2, id);
@@ -296,17 +301,16 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 
 	@Override
 	public List<T> queryAll() {
+		return queryAll(Integer.MAX_VALUE, 0);
+	}
+
+	@Override
+	public List<T> queryAll(long limit, long offset) {
 
 		List<T> list = new ArrayList<>();
 
-		String sql;
+		String sql = getLimitSql(limit, offset, queryAllAsXmlSqlS, queryAllAsJsonSqlS, queryAllAsXmlLimitSqlS,
-		if (this.dataType == DataType.xml)
+				queryAllAsJsonLimitSqlS);
-			sql = queryAllAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = queryAllAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement statement = this.connection.prepareStatement(sql)) {
 
@@ -326,25 +330,29 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 	}
 
 	@Override
-	public List<T> queryAll(String type) {
+	public List<T> queryAll(String... types) {
+		return queryAll(Integer.MAX_VALUE, 0, types);
+	}
+
+	@Override
+	public List<T> queryAll(long limit, long offset, String... types) {
+		if (types.length == 0)
+			return queryAll(limit, offset);
 
 		List<T> list = new ArrayList<>();
 
-		String sql;
+		String sql = getLimitSql(limit, offset, queryAllByTypeAsXmlSqlS, queryAllByTypeAsJsonSqlS,
-		if (this.dataType == DataType.xml)
+				queryAllByTypeAsXmlLimitSqlS, queryAllByTypeAsJsonLimitSqlS);
-			sql = queryAllByTypeAsXmlSqlS;
-		else if (this.dataType == DataType.json)
-			sql = queryAllByTypeAsJsonSqlS;
-		else
-			throw new IllegalStateException("Unhandled DataType " + this.dataType);
-		sql = MessageFormat.format(sql, getTableName());
 
 		try (PreparedStatement statement = this.connection.prepareStatement(sql)) {
-			statement.setString(1, type);
+
+			Array typesArray = statement.getConnection().createArrayOf("varchar", types);
+			statement.setArray(1, typesArray);
 
 			try (ResultSet result = statement.executeQuery()) {
 				while (result.next()) {
 					String id = result.getString("id");
+					String type = result.getString("type");
 					list.add(parseDbObject(result, id, type));
 				}
 
@@ -356,6 +364,37 @@ public abstract class PostgresqlDao<T extends StrolchRootElement> implements Str
 		}
 	}
 
+	protected String getLimitSql(long limit, long offset, String xmlSql, String jsonSql, String xmlLimitSql,
+			String jsonLimitSql) {
+
+		String sql;
+		if (limit == Integer.MAX_VALUE) {
+			return getSql(xmlSql, jsonSql);
+		}
+
+		if (this.dataType == DataType.xml)
+			sql = xmlLimitSql;
+		else if (this.dataType == DataType.json)
+			sql = jsonLimitSql;
+		else
+			throw new IllegalStateException("Unhandled DataType " + this.dataType);
+
+		return MessageFormat.format(sql, getTableName(), limit, offset);
+	}
+
+	protected String getSql(String xmlSql, String jsonSql) {
+
+		String sql;
+		if (this.dataType == DataType.xml)
+			sql = xmlSql;
+		else if (this.dataType == DataType.json)
+			sql = jsonSql;
+		else
+			throw new IllegalStateException("Unhandled DataType " + this.dataType);
+
+		return MessageFormat.format(sql, getTableName());
+	}
+
 	@Override
 	public void save(T res) {
 		this.commands.add(txResult -> {

li.strolch.persistence.xml/src/main/java/li/strolch/persistence/xml/AbstractDao.java

@@ -37,6 +37,11 @@ public abstract class AbstractDao<T extends StrolchRootElement> implements Strol
 		this.tx = strolchTx.getTx();
 	}
 
+	@Override
+	public boolean supportsPaging() {
+		return false;
+	}
+
 	protected abstract String getClassType();
 
 	protected IdOfSubTypeRef getIdRef(String type, String id) {
@@ -52,7 +57,6 @@ public abstract class AbstractDao<T extends StrolchRootElement> implements Strol
 		long size = 0;
 		Set<String> types = queryTypes();
 		for (String type : types) {
-
 			SubTypeRef subTypeRef = getTypeRef(type);
 			size += this.tx.getMetadataDao().querySize(subTypeRef);
 		}
@@ -60,9 +64,23 @@ public abstract class AbstractDao<T extends StrolchRootElement> implements Strol
 	}
 
 	@Override
-	public long querySize(String type) {
+	public long querySize(String... types) {
-		SubTypeRef subTypeRef = getTypeRef(type);
+
-		return this.tx.getMetadataDao().querySize(subTypeRef);
+		if (types.length == 0)
+			return querySize();
+
+		if (types.length == 1) {
+			SubTypeRef subTypeRef = getTypeRef(types[0]);
+			return this.tx.getMetadataDao().querySize(subTypeRef);
+		}
+
+		int size = 0;
+		for (String type : types) {
+			SubTypeRef subTypeRef = getTypeRef(type);
+			size += this.tx.getMetadataDao().querySize(subTypeRef);
+		}
+
+		return size;
 	}
 
 	@Override
@@ -84,8 +102,20 @@ public abstract class AbstractDao<T extends StrolchRootElement> implements Strol
 	}
 
 	@Override
-	public List<T> queryAll(String type) {
+	public List<T> queryAll(String... types) {
-		return this.tx.getObjectDao().queryAll(getTypeRef(type));
+		if (types.length == 0)
+			return queryAll();
+
+		if (types.length == 1) {
+			return this.tx.getObjectDao().queryAll(getTypeRef(types[0]));
+		}
+
+		List<T> objects = new ArrayList<>();
+		for (String type : types) {
+			objects.addAll(this.tx.getObjectDao().queryAll(getTypeRef(type)));
+		}
+
+		return objects;
 	}
 
 	@Override
@@ -135,6 +165,16 @@ public abstract class AbstractDao<T extends StrolchRootElement> implements Strol
 		// nothing to do
 	}
 
+	@Override
+	public List<T> queryAll(long limit, long offset) throws StrolchPersistenceException {
+		throw new UnsupportedOperationException("Paging not supported! Check first with supportsPaging()");
+	}
+
+	@Override
+	public List<T> queryAll(long limit, long offset, String... types) throws StrolchPersistenceException {
+		throw new UnsupportedOperationException("Paging not supported! Check first with supportsPaging()");
+	}
+
 	@Override
 	public void removeVersion(T element) throws StrolchPersistenceException {
 		throw new UnsupportedOperationException("Versioning is not supported!");