Shulou(Shulou.com)05/31 Report--

This article is about how EXPDP estimates the derived space estimate,estimate_only. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

ESTIMATE

Default: blocks

Specify how to calculate the disk space used by each table

ESTIMATE= [BLOCKS | STATISTICS]

1.BLOCKS-calculated by the number and size of blocks?

2.STATISTICS-calculation of statistics per table

Limit

1. If the table is compressed, then the value calculated using ESTIMATE=BLOCKS is not accurate, so ESTIMATE=STATISTICS.? should be used at this time

two。 It is also not accurate when the QUERY,REMAP_DATA parameter is used

? [oracle@lzl ~] $expdp scott/tiger TABLES=emp ESTIMATE=STATISTICS DIRECTORY=lzl_dir DUMPFILE=estimate_stat.dmp

Export: Release 11.2.0.3.0-Production on Wed Jul 12 23:29:44 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0-64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

Starting "SCOTT". "SYS_EXPORT_TABLE_01": scott/* TABLES=emp ESTIMATE=STATISTICS DIRECTORY=lzl_dir

Estimate in progress using STATISTICS method...

Processing object type TABLE_EXPORT/TABLE/TABLE_DATA

. Estimated "SCOTT". "EMP" 8.203 KB-estimated size

Total estimation using STATISTICS method: 8.203 KB

Processing object type TABLE_EXPORT/TABLE/TABLE

Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS

. . Exported "SCOTT". "EMP" 8.562 KB 14 rows-actual size

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

*

Dump file set for SCOTT.SYS_EXPORT_TABLE_01 is:

/ home/oracle/expdat.dmp

Job "SCOTT". "SYS_EXPORT_TABLE_01" successfully completed at 23:29:49

ESTIMATE_ONLY

Default: no

If ESTIMATE_ONLY=YES, only estimating the space occupied by the export will not do the actual export work. Can be used to estimate the derived space.

Restrictions:

Cannot be used with the QUERY parameter

Thank you for reading! This is the end of the article on "how to estimate the export space estimate,estimate_only of EXPDP". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it out for more people to see!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.