The parent for all AVL node implementations. Subclasses of Node vary in the way they hold references to other Nodes in the AVL tree, or to their Row data.
nNext links the Node objects belonging to different indexes for each table row. It is used solely by Row to locate the node belonging to a particular index.
New class derived from Hypersonic SQL code and enhanced in HSQLDB.
@author Thomas Mueller (Hypersonic SQL Group)
@version 1.9.0
@since Hypersonic SQL