lob 按ROWID分区并行导出

分享个公司大神写的LOB手动分片导出脚本，非常好用，当然了，大表还是做分区比较好哇：

set verify off undefine rowid_ranges undefine segment_name undefine owner set head off set pages 0 set trimspool on   select 'where rowid between ''' ||sys.dbms_rowid.rowid_create(1, d.oid, c.fid1, c.bid1, 0) ||''' and ''' ||sys.dbms_rowid.rowid_create(1, d.oid, c.fid2, c.bid2, 9999) || '''' ||';'   from (select distinct b.rn,                         first_value(a.fid) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) fid1,                         last_value(a.fid) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) fid2,                         first_value(decode(sign(range2 - range1),                                            1,                                            a.bid +                                            ((b.rn - a.range1) * a.chunks1),                                            a.bid)) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) bid1,                         last_value(decode(sign(range2 - range1),                                           1,                                           a.bid +                                           ((b.rn - a.range1 + 1) * a.chunks1) - 1,                                           (a.bid + a.blocks - 1))) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) bid2           from (select fid,                        bid,                        blocks,                        chunks1,                        trunc((sum2 - blocks + 1 - 0.1) / chunks1) range1,                        trunc((sum2 - 0.1) / chunks1) range2                   from (select /*+ rule */                          relative_fno fid,                          block_id bid,                          blocks,                          sum(blocks) over() sum1,                          trunc((sum(blocks) over()) / &&rowid_ranges) chunks1,                          sum(blocks) over(order by relative_fno, block_id) sum2                           from dba_extents                          where segment_name = upper('&&segment_name')                            and owner = upper('&&owner'))                  where sum1 > &&rowid_ranges) a,                (select rownum - 1 rn                   from dual                 connect by level <= &&rowid_ranges) b          where b.rn between a.range1 and a.range2) c,        (select max(data_object_id) oid           from dba_objects          where object_name = upper('&&segment_name')            and owner = upper('&&owner')            and data_object_id is not null) d            /