How to use partition name as a parameter in the select statement?

问题

I have a huge table that I need to transfer into a new table, my resources do not allow me to that and I need to do that by chunking of data like this:

DECLARE
  TYPE prod_tab IS TABLE OF dba_tab_partitions%ROWTYPE;
  products_tab   prod_tab := prod_tab();
  start_time  number;  end_time   number;
BEGIN

  SELECT * BULK COLLECT INTO products_tab FROM dba_tab_partitions WHERE table_name = 'TBLX'

  EXECUTE IMMEDIATE 'TRUNCATE TABLE dba_tab_partitions2';
  EXECUTE IMMEDIATE 'TRUNCATE TABLE tbl2';

  FOR i in products_tab.first .. products_tab.last LOOP
    EXECUTE IMMEDIATE 'ALTER SESSION FORCE PARALLEL DML PARALLEL 24';
    INSERT /* PARALLEL(24) NOLOGGING */ INTO tbla2 NOLOGGING
    (
      "ID", datetime, ...)
    SELECT /* PARALLEL(24) NOLOGGING */ * FROM tbl1 PARTITION(products_tab(i).partition_name);
    COMMIT;

  END LOOP;

  COMMIT;
END;

Could anybody help me to correct it?

回答1:

As already stated in my comments I think PARALLEL does not make any sense (but I am not sure about that) and running each partition one by one is also useless when you copy entire table.

Anyway, your code should work when you write it like this:

FOR i in products_tab.first .. products_tab.last LOOP
   EXECUTE IMMEDIATE 'ALTER SESSION FORCE PARALLEL DML PARALLEL 24';
   EXECUTE IMMEDIATE 'INSERT /*+ APPEND PARALLEL(24) */ INTO tbla2
      ("ID", datetime, ...)
   SELECT * 
   FROM tbl1 PARTITION ('||products_tab(i).partition_name||)';
   COMMIT;

END LOOP;

I don't know your requirements but maybe Exchanging Partitions and Subpartitions could be an option for you.

来源：https://stackoverflow.com/questions/46959197/how-to-use-partition-name-as-a-parameter-in-the-select-statement

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Oracle