Concatenate in PL/SQL

Question

Team:
I have a requirement like this. I have to give remap_tablespace=src1:dest1,src2:dest2,src3:dest3,src4:dest1 ...etc in import using datapump in a shell script for schema cloning. I have written the below code for that, cursor get_tabspace1 for source1 & cursor get_tabspace2 for destination1. Destination cursor has only 3 tablespaces (static). Whereas source cursor has many tablespaces. While remapping for example: I have taken source tablespace1 with destination tablespace1, source  tablespace2 with destination tablespace2, source  tablespace3 with destination tablespace3, source  tablespace4 with destination tablespace1 (destination round robin method as it is static & have only 3 tablespaces), source tablespace5 with destination tablespace2 (destination round robin method as it is static & have only 3 tablespaces), source tablespace6 with destination tablespace3 (destination round robin method as it is static & have only 3 tablespaces). For the above example I have written the below code. I am having difficulty in getting the string like this src1:dest1,src2:dest2,src3:dest3,src4:dest1. Please let me know how to concatenate inside the loop to get this string. I have written the below 2 lines of code as shown below. concat:=map_tabspace_i: || remap_tabspace_i, concat:=concat || map_tabspace_i: || remap_tabspace_i, I think this will not get into this format src1:dest1,src2:dest2,src3:dest3,src4:dest1 ...etc. Please correct me what I have to write to get string like this src1:dest1,src2:dest2,src3:dest3,src4:dest1 ...etc
declare
cursor get_tabspace1 is select distinct TABLESPACE_NAME from dba_segments where owner='JOHN';
cursor get_tabspace2 is select distinct TABLESPACE_NAME from dba_segments where owner='NANCY';
begin
i:=1;
t:=1;
concat varchar2(2000);
OPEN get_tabspace1;
OPEN get_tabspace2;
   LOOP
   FETCH get_tabspace1 INTO v_tabspace_name1;
   EXIT WHEN get_tabspace1%NOTFOUND;
   while (t>3) LOOP
   CLOSE get_tabspace2;
   OPEN get_tabspace2;
   EXIT WHEN get_tabspace1%NOTFOUND;
   t:=1;
   END LOOP;
   FETCH get_tabspace2 INTO v_tabspace_name2;
   map_tabspace_i := v_tabspace_name1;
   remap_tabspace_i := v_tabspace_name2;
   concat:=map_tabspace_i: || remap_tabspace_i,
   concat:=concat || map_tabspace_i: || remap_tabspace_i,
   i:=i+1;
   t:=t+1;
   END LOOP;
CLOSE get_tabspace1;
CLOSE get_tabspace2;
exception
   WHEN OTHERS THEN
      raise_application_error(-20001,'An error was encountered - '||SQLCODE||' -ERROR- '||SQLERRM);
end;
Thanks in Advance for replying.

Answer 1

Input from the SQL script need to be passed to IMPDP - remap_tablespace command using round robin method based on the source tablespaces
impdp REMAP_SCHEMA=john:Nancy remap_tablespace=SRC_TS_1:TGT_TS_1 remap_tablespace=SRC_TS_2:TGT_TS_2 remap_tablespace=SRC_TS_3:TGT_TS_3 remap_tablespace=SRC_TS_4:TGT_TS_1 remap_tablespace=SRC_TS_5:TGT_TS_2 ..etc
Here's pl/sql version you asked. Consider API that John suggested - i would DBMS_DATAPUMP
set serveroutput on
declare
  p_schema varchar2(30) := 'JOHN';
  type    target_type  is varray(3) of varchar2(30);
  target  target_type   := target_type('TGT_TS_1', 'TGT_TS_2', 'TGT_TS_3');
  i       pls_integer   := 1;
  remap   varchar2(500);
begin
  for r in (select distinct tablespace_name from dba_segments where owner = p_schema)
  loop
    -- round robin target tablespace
    remap := remap || ' remap_tablespace ' || r.tablespace_name || ':' || target(i);
    if (i < target.count) then
      i := i + 1;
    else
      i := 1;
    end if;
  end loop;
  dbms_output.put_line(remap);
end;