Oracle 18c

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CREATE TABLE EXPORT_TABLE (
  TABLE_OWNER     VARCHAR2(30),
  TABLE_NAME      VARCHAR2(30),
  PARTITION_NAME  VARCHAR2(30),
  HIGH_VALUE      LONG,
  NUM_ROWS        INTEGER
); 
INSERT INTO EXPORT_TABLE VALUES ( 'TO', 'TN', 'PN', 'TIMESTAMP ''2019-06-26 12:34:56''', 12345 );
1 rows affected

ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
WITH FUNCTION clobToDate( value IN CLOB ) RETURN DATE
  IS
    ts DATE;
  BEGIN
    EXECUTE IMMEDIATE 'BEGIN :ts := ' || value || '; END;' USING OUT ts;
    RETURN ts;
  END;
SELECT TABLE_OWNER,
       TABLE_NAME,
       PARTITION_NAME,
       clobToDate(
         EXTRACTVALUE(
           dbms_xmlgen.getxmltype(
             'SELECT high_value'
             || ' FROM  EXPORT_TABLE'
             || ' WHERE TABLE_OWNER    = ''' || t.table_owner || ''''
             || ' AND   TABLE_NAME     = ''' || t.table_name || ''''
             || ' AND   PARTITION_NAME = ''' || t.partition_name || ''''
           ),
           '//text()'
         )
       ) AS HIGH_VALUE,
       NUM_ROWS
FROM   EXPORT_TABLE t;


TABLE_OWNER
TABLE_NAME
PARTITION_NAME
HIGH_VALUE
NUM_ROWS


TO
TN
PN
2019-06-26 12:34:56
12345