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diff --git a/petascope/src/petascope/wcps/server/core/XmlQuery.java b/petascope/src/petascope/wcps/server/core/XmlQuery.java
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+++ b/petascope/src/petascope/wcps/server/core/XmlQuery.java
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+/*
+ * This file is part of PetaScope.
+ *
+ * PetaScope is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * PetaScope is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with PetaScope. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * For more information please see <http://www.PetaScope.org>
+ * or contact Peter Baumann via <baumann@rasdaman.com>.
+ *
+ * Copyright 2009 Jacobs University Bremen, Peter Baumann.
+ */
+package petascope.wcps.server.core;
+
+import petascope.wcps.server.exceptions.InvalidCrsException;
+import petascope.wcps.server.exceptions.WCPSException;
+import org.w3c.dom.*;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+
+/**
+ *
+ * @author Andrei Aiordachioaie
+ */
+public class XmlQuery implements IRasNode {
+
+    private String mime;
+    private ArrayList<CoverageIterator> iterators;
+    private BooleanScalarExpr where;
+    private IRasNode coverageExpr;
+    private IDynamicMetadataSource meta;
+    private ArrayList<CoverageIterator> dynamicIterators;
+    /* Variables used in the XML query are renamed. The renaming is explained below.
+     *
+     * Variables declared in the same expression (construct, const, condense)
+    will be collapsed into one multidimensional variable name. For
+    "construct img over $px x(1:10), $py y(1:10) values ... ", the variables could
+    be translated as: $px -> "iteratorA[0]", $py -> "iteratorA[1]".
+     * Variables declared in different expression will have different prefixes,
+    built from "varPrefix" + "varStart".
+     *
+
+     * Used in condenser, construct and constant coverage expressions. */
+    // VariableIndexCount stores the dimensionality of each renamed variable
+    private HashMap<String, Integer> varDimension;
+    // VariableNewName is used to translate the old var name into the multi-dim var name
+    private HashMap<String, String> variableTranslator;
+    private String varPrefix = "i_";
+    private char varSuffix = 'i';
+
+    public String getMimeType() {
+        return mime;
+    }
+
+    public XmlQuery(IDynamicMetadataSource source) {
+        super();
+        this.meta = source;
+        iterators = new ArrayList<CoverageIterator>();
+        dynamicIterators = new ArrayList<CoverageIterator>();
+        variableTranslator = new HashMap<String, String>();
+        varDimension = new HashMap<String, Integer>();
+    }
+
+    public XmlQuery(Node node) throws WCPSException, InvalidCrsException {
+        iterators = new ArrayList<CoverageIterator>();
+        dynamicIterators = new ArrayList<CoverageIterator>();
+        variableTranslator = new HashMap<String, String>();
+        varDimension = new HashMap<String, Integer>();
+        this.startParsing(node);
+    }
+
+    public void startParsing(Node node) throws WCPSException, InvalidCrsException {
+        System.err.println("Processing XML Request: " + node.getNodeName());
+
+        Node x = node.getFirstChild();
+
+
+        while (x != null) {
+            if (x.getNodeName().equals("#text")) {
+                x = x.getNextSibling();
+                continue;
+            }
+
+            System.err.println("The current node is: " + x.getNodeName());
+
+            if (x.getNodeName().equals("coverageIterator")) {
+                iterators.add(new CoverageIterator(x, this));
+            } else if (x.getNodeName().equals("where")) {
+                where = new BooleanScalarExpr(x.getFirstChild(), this);
+            } else if (x.getNodeName().equals("encode")) {
+                EncodeDataExpr encode;
+
+                encode = new EncodeDataExpr(x, this);
+                coverageExpr = encode;
+                mime = encode.getMime();
+            } else {
+                // It has to be a scalar Expr 
+                coverageExpr = new ScalarExpr(x, this);
+                mime = "text/plain";
+            }
+
+            x = x.getNextSibling();
+        }
+    }
+
+    public Boolean isIteratorDefined(String iteratorName) {
+        Iterator<CoverageIterator> it = iterators.iterator();
+        while (it.hasNext()) {
+            CoverageIterator tmp = it.next();
+            if (iteratorName.equals(tmp.getIteratorName())) {
+                return true;
+            }
+        }
+
+        it = dynamicIterators.iterator();
+        while (it.hasNext()) {
+            CoverageIterator tmp = it.next();
+            if (iteratorName.equals(tmp.getIteratorName())) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /* Stores information about dynamically created iterators, as metadata.
+     * For example, from a Construct Coverage expression.
+     */
+    public void addDynamicCoverageIterator(CoverageIterator i) {
+        dynamicIterators.add(i);
+    }
+
+    public Iterator<String> getCoverages(String iteratorName) throws WCPSException {
+        for (int i = 0; i < iterators.size(); ++i) {
+            if (iterators.get(i).getIteratorName().equals(iteratorName)) {
+                return iterators.get(i).getCoverages();
+            }
+        }
+
+        for (int i = 0; i < dynamicIterators.size(); ++i) {
+            if (dynamicIterators.get(i).getIteratorName().equals(iteratorName)) {
+                return dynamicIterators.get(i).getCoverages();
+            }
+        }
+
+        throw new WCPSException("Iterator " + iteratorName + " not defined");
+    }
+
+    public boolean isDynamicCoverage(String coverageName) {
+        for (int i = 0; i < dynamicIterators.size(); ++i) {
+            Iterator<String> iterator =
+                    ((CoverageIterator) dynamicIterators.get(i)).getCoverages();
+            while (iterator.hasNext()) {
+                if (iterator.next().equals(coverageName)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    /** Creates a new (translated) variable name for an expression that
+     * has referenceable variables.
+     * @return String a new variable name assigned
+     */
+    public String registerNewExpressionWithVariables() {
+        String name = varPrefix + varSuffix;
+        varDimension.put(name, 0);
+        varSuffix++;
+        return name;
+    }
+
+    /** Remember a variable that can be referenced in the future. This function
+     * assigns it a index code, that should then be used to reference that variable
+     * in the RasQL query.
+     *
+     * If the variable is already referenced, then this function does nothing.
+     * @param name Variable name
+     */
+    public boolean addReferenceVariable(String name, String translatedName) {
+        if (varDimension.containsKey(translatedName) == false) {
+            return false;
+        }
+
+        Integer index = varDimension.get(translatedName);
+        Integer newIndex = index + 1;
+        varDimension.put(translatedName, newIndex);
+        variableTranslator.put(name, translatedName + "[" + index + "]");
+
+        return true;
+    }
+
+    /** Retrieve the translated name assigned to a specific reference (scalar) variable */
+    public String getReferenceVariableName(String name) throws WCPSException {
+        String newName = variableTranslator.get(name);
+        return newName;
+    }
+
+    public String toRasQL() {
+        String result = "select " + coverageExpr.toRasQL() + " from ";
+        Iterator<CoverageIterator> it = iterators.iterator();
+        boolean first = true;
+
+        while (it.hasNext()) {
+            if (first) {
+                first = false;
+            } else {
+                result += ", ";
+            }
+
+            result += it.next().toRasQL();
+        }
+
+        if (where != null) {
+            result += " where " + where.toRasQL();
+        }
+
+        return result;
+    }
+
+    public IDynamicMetadataSource getMetadataSource() {
+        return meta;
+    }
+}