f88306dd_enas_mais_um_blog_sobre_Oracle__Type_of_Limit
[Item] Subqueries [Limit Value] Unlimited in the FROM clause of the top-level query 255 subqueries in the WHERE clause [Type of Limit] 
Maximum levels of subqueries in a SQL statement
Alessandro Guimarães - Oracle Blog | Apenas mais um blog sobre Oracle
Type of Limit