user-defined tree methods in GIST

I need some help in building new index structure using GIST.<br /> I have to include a procedure for restructuring the
treeimmediately after i have created the index using gist. How do i do it?<br />Actually I am trying to implement the
slim-treeindex using gist. To increase the performance, a slim-down algorithm runs after creation of the slim-tree.
Wherecan i give a call to this slim-down procedure after the tree has been built using gist? <br /><br />Regards<br
/>Sharat.<br/>