One of Oracle statement optimizations

 PublicList<tddepartment>CREATEZTREEDEP (String compid) {List<TdDepartment> DD =NewArraylist<tddepartment>(); Find SQL statements for all child departments
String SQL = "Select Dep_id,dep_name,super_id,folder from Td_department" + "Start with super_id in (" + "Select dep_id from Td_department" + "where VALID_FL AG = ' Y ' and comp_id = ' "+compid+" ') connect by prior dep_id = super_id ";        
Find the SQL statement for the department itself String parentsql = "Select dep_id, Dep_name,super_id,folder from td_department" + "where Valid_flag = ' Y ' and comp _id = ' "+compid+" ' ";
epdb DB=Newepdb (); ArrayList<HashMap> Parentdeparts =Db.gethashdata (Parentsql); ArrayList<HashMap> departs =db.gethashdata (SQL); if(Parentdeparts = =NULL|| Parentdeparts.size () <= 0)            return NULL;
Add a department to the listfor (int i=0; i<parentdeparts.size (); i++) {String dep_id = Parentdeparts.get (i            ). Get ("dep_id"). ToString ();            String dep_name = Parentdeparts.get (i). Get ("Dep_name"). ToString ();                        String super_id = Parentdeparts.get (i). Get ("super_id"). ToString ();            Tddepartment td = New Tddepartment ();            Td.setid (dep_id);            Td.setpid (super_id);            Td.setname (Dep_name); if (Parentdeparts.get (i). Get ("folder") = null) {String folder = Parentdeparts.get (i). Get ("folder"). toString                (); if ("Y". Equals (folder)) {Td.setopen ("true");//non-leaf nodes need to be expanded}else{Td.set                Open ("false");            }}//Cancel loop read//td.setchild (createdepartments (dep_id));  Dd.add (TD); } //Add child departments to list for (int i=0; i<departs.size (); i++) {String dep_id = Departs.get (i). Get ("dep_id"). ToString ();            String dep_name = Departs.get (i). Get ("Dep_name"). ToString ();                        String super_id = Departs.get (i). Get ("super_id"). ToString ();            Tddepartment td = New Tddepartment ();            Td.setid (dep_id);            Td.setpid (super_id);            Td.setname (Dep_name);                if (Departs.get (i). Get ("folder") = null) {String folder = Departs.get (i). Get ("folder"). ToString ();                    if ("Y". Equals (folder)) {Td.setopen ("true");//non-leaf nodes need to be expanded}else{                Td.setopen ("false");                        }}//Cancel loop read//td.setchild (createdepartments (dep_id));        Dd.add (TD); }                returnDD; }

Need to optimize points:

Think one: Optimize with SQL statement optimization

Thinking two: Optimizing by means of program recursion

One of Oracle statement optimizations