I am facing huge problem with our existing category listing. One of our client has 65,000 nested category.
First Level is limited to 10 only.
Cat A
  Cat B
     Cat B_a
     Cat B_b
     Cat B_c
     Cat B_d
  Cat C
  Cat D
  ....
Cat AA
  Cat B
  Cat C
  Cat D
  ....
Cat AAA 
......
Existing code is generating a array with these kind of SQL
SELECT * 
  FROM kl_document_user_label 
  WHERE 
    customer_id='xxx' 
    and position RLIKE '^([0-9]+>){1,1}$' 
    AND ( user_crerate='0' OR user_crerate='1') 
  ORDER BY 
    ulable_name
In Case of 65,000 nested category it hanged.
 
     
    