We need these two fellows for the previous patch to make sense.

src/java/com/samskivert/depot/clause/CreateIndexClause.java

@@ -0,0 +1,93 @@
+//
+// $Id: $
+//
+// Depot library - a Java relational persistence library
+// Copyright (C) 2006-2008 Michael Bayne and Pär Winzell
+//
+// This library 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 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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 this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.depot.clause;
+
+import java.util.Collection;
+import java.util.List;
+
+import com.samskivert.depot.PersistentRecord;
+import com.samskivert.depot.clause.OrderBy.Order;
+import com.samskivert.depot.expression.SQLExpression;
+import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.util.Tuple;
+
+/**
+ * Represents an CREATE INDEX instruction to the database.
+ */
+public class CreateIndexClause<T extends PersistentRecord>
+    implements QueryClause
+{
+    /**
+     * Create a new {@link CreateIndexClause} clause. The name must be unique within the
+     * relevant database.
+     */
+    public CreateIndexClause (
+        Class<? extends PersistentRecord> pClass, String name, boolean unique,
+        List<Tuple<SQLExpression, Order>> fields)
+
+    {
+        _pClass = pClass;
+        _name = name;
+        _unique = unique;
+        _fields = fields;
+    }
+
+    public Class<? extends PersistentRecord> getPersistentClass ()
+    {
+        return _pClass;
+    }
+
+    public String getName ()
+    {
+        return _name;
+    }
+
+    public boolean isUnique ()
+    {
+        return _unique;
+    }
+
+    public List<Tuple<SQLExpression,Order>> getFields ()
+    {
+        return _fields;
+    }
+
+    // from SQLExpression
+    public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
+    {
+        classSet.add(_pClass);
+    }
+
+    // from SQLExpression
+    public void accept (ExpressionVisitor builder)
+    {
+        builder.visit(this);
+    }
+
+    protected Class<? extends PersistentRecord> _pClass;
+
+    protected String _name;
+
+    protected boolean _unique;
+
+    /** The components of the index, e.g. columns or functions of columns. */
+    protected List<Tuple<SQLExpression,Order>> _fields;
+}

src/java/com/samskivert/depot/clause/DropIndexClause.java

@@ -0,0 +1,64 @@
+//
+// $Id: $
+//
+// Depot library - a Java relational persistence library
+// Copyright (C) 2006-2008 Michael Bayne and Pär Winzell
+//
+// This library 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 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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 this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.depot.clause;
+
+import java.util.Collection;
+
+import com.samskivert.depot.PersistentRecord;
+import com.samskivert.depot.impl.ExpressionVisitor;
+
+/**
+ * Represents an DROP INDEX instruction to the database.
+ */
+public class DropIndexClause<T extends PersistentRecord> implements QueryClause
+{
+    public DropIndexClause (Class<? extends PersistentRecord> pClass, String name)
+    {
+        _pClass = pClass;
+        _name = name;
+    }
+
+    public Class<? extends PersistentRecord> getPersistentClass ()
+    {
+        return _pClass;
+    }
+
+    public String getName ()
+    {
+        return _name;
+    }
+
+    // from SQLExpression
+    public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
+    {
+        classSet.add(_pClass);
+    }
+
+    // from SQLExpression
+    public void accept (ExpressionVisitor builder)
+    {
+        builder.visit(this);
+    }
+
+    protected Class<? extends PersistentRecord> _pClass;
+
+    protected String _name;
+}