关于在数据泵问题:

(1)索引数据导出吗?

(2)源表统计数据导出/导入吗？

1创建测试表

drop table test;

create table test

as

select dbms_random.string('x',50) as x from dual

connect by level<=1e6;

create index idx_test_x on test(x);

begin

dbms_stats.gather_table_stats(user,'TEST');

end;

/

select table_name,num_rows,blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_tables where table_name='TEST';

TABLE_NAME   NUM_ROWS     BLOCKS L_ANAY

---------- ---------- ---------- --------------------

TEST           997971       7884 20140315 153237

select index_name,leaf_blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_indexes where table_name='TEST';

INDEX_NAME      LEAF_BLOCKS L_ANAY

--------------- ----------- --------------------

IDX_TEST_X             8467 20140315 153238

col segment_name for a20

select segment_name,bytes/1024/1024 from user_segments where segment_name in('TEST','IDX_TEST_X');

SEGMENT_NAME         BYTES/1024/1024

-------------------- ---------------

TEST                              62

IDX_TEST_X                        72

2修改统计数据

begin

dbms_stats.set_table_stats(ownname => user,tabname => 'TEST',numrows => 1000,numblks => 100);

end;

/

begin

dbms_stats.set_index_stats(ownname => user,indname => 'IDX_TEST_X',numlblks => 100);

end;

/

select table_name,num_rows,blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_tables where table_name='TEST';

TABLE_NAME   NUM_ROWS     BLOCKS L_ANAY

---------- ---------- ---------- --------------------

TEST             1000        100 20140315 153457

select index_name,leaf_blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_indexes where table_name='TEST';

INDEX_NAME      LEAF_BLOCKS L_ANAY

--------------- ----------- --------------------

IDX_TEST_X              100 20140315 153457

3包含/不包含索引导出

(1)不包含索引导出

mah]$ expdp \'sys/sys as sysdba\' directory='DMP_DIR' tables=MH.TEST dumpfile=test.dmp exclude=INDEX estimate=statistics

Export: Release 10.2.0.1.0 - Production on Saturday, 15 March, 2014 15:36:19

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production

With the Partitioning, OLAP and Data Mining options

Starting "SYS"."SYS_EXPORT_TABLE_01":  'sys/******** AS SYSDBA' directory=DMP_DIR tables=MH.TEST dumpfile=test.dmp exclude=INDEX estimate=statistics

Estimate in progress using STATISTICS method...

Processing object type TABLE_EXPORT/TABLE/TABLE_DATA

.  estimated "MH"."TEST"                                 54.86 KB   ==>estimate=blocks时,估计为62 MB

Total estimation using STATISTICS method: 54.86 KB

Processing object type TABLE_EXPORT/TABLE/TABLE

Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS

. . exported "MH"."TEST"                                 52.45 MB 1000000 rows

Master table "SYS"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded

******************************************************************************

Dump file set for SYS.SYS_EXPORT_TABLE_01 is:

/home/oracle/mah/test.dmp

Job "SYS"."SYS_EXPORT_TABLE_01" successfully completed at 15:36:26

(2)包含索引导出

[oracle@rhel5 mah]$ expdp \'sys/sys as sysdba\' directory='DMP_DIR' tables=MH.TEST dumpfile=test2.dmp  estimate=statistics

Export: Release 10.2.0.1.0 - Production on Saturday, 15 March, 2014 15:37:22

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production

With the Partitioning, OLAP and Data Mining options

Starting "SYS"."SYS_EXPORT_TABLE_01":  'sys/******** AS SYSDBA' directory=DMP_DIR tables=MH.TEST dumpfile=test2.dmp estimate=statistics

Estimate in progress using STATISTICS method...

Processing object type TABLE_EXPORT/TABLE/TABLE_DATA

.  estimated "MH"."TEST"                                 54.86 KB

Total estimation using STATISTICS method: 54.86 KB

Processing object type TABLE_EXPORT/TABLE/TABLE

Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX

Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS

Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS

. . exported "MH"."TEST"                                 52.45 MB 1000000 rows

Master table "SYS"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded

******************************************************************************

Dump file set for SYS.SYS_EXPORT_TABLE_01 is:

/home/oracle/mah/test2.dmp

Job "SYS"."SYS_EXPORT_TABLE_01" successfully completed at 15:37:30

导出文件比较:

[oracle@rhel5 mah]$ ls -lrt

-rw-r----- 1 oracle oinstall 55070720 Mar 15 15:36 test.dmp

-rw-r----- 1 oracle oinstall 55078912 Mar 15 15:37 test2.dmp  ==>含索引

==>两个文件大小差异极小(8192bytes),因TEST表上索引列较大(50bytes*1000000rows),不可能含索引数据;多出来的数据块仅包含索引结构.

4导入

(1)删除表MH.TEST后:

impdp \'sys/sys as sysdba\' directory='DMP_DIR' tables=MH.TEST dumpfile=test.dmp

SQL> select table_name,num_rows,blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_tables where table_name='TEST';

TABLE_NAME   NUM_ROWS     BLOCKS L_ANAY

---------- ---------- ---------- --------------------

TEST             1000        100 20140315 153457

SQL> select index_name,leaf_blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_indexes where table_name='TEST';

no rows selected

(2)删除表MH.TEST后:

impdp \'sys/sys as sysdba\' directory='DMP_DIR' tables=MH.TEST dumpfile=test2.dmp

SQL> select table_name,num_rows,blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_tables where table_name='TEST';

TABLE_NAME   NUM_ROWS     BLOCKS L_ANAY

---------- ---------- ---------- --------------------

TEST             1000        100 20140315 153457

SQL> select index_name,leaf_blocks,to_char(last_analyzed,'YYYYMMDD hh24miss') as l_anay from user_indexes where table_name='TEST';

INDEX_NAME      LEAF_BLOCKS L_ANAY

--------------- ----------- --------------------

IDX_TEST_X              100 20140315 153457

==>行数和数据块是导出时设置的统计信息,而不是数据本身真实分布信息,包括索引和表上的上次分析时间

5结论

(1)expdp不导出索引数据,仅导出索引DDL

(2)expdp/impdp分别导出/导入统计数据