Re: Questions about Import/Export

Usually performance increases observed after an export/import are due to row chaining being eliminated instead of fixing fragmentation problems. Look at how much chaining is occurring after your DML activity and try adjusting your percent free and percent used to reduce the amount of chaining.

Schema objects are best dropped using "drop user <username> cascade all" and then let the import re-create everything. You could disable index creation during the import and it would go faster. Just have the scripts necessary to re-create your indexes after the database has been restored.

HTH

--
Jim Gregory
Principal Consultant for Keane, Inc.
Currently assigned to NCR
"Opinions are my own and do not reflect
  those of Keane or my clients"
Dino Hsu <dino1_at_ms1.hinet.net> wrote in message
news:8l9peq$3vm78$1_at_ID-41926.news.cis.dfn.de...


> Dear All,

>

> I have questions about import/export:

> 1.I am told that we can improve the performance of a database by exporting

> the database and then importing it back when the database is too

 fragmented


> after many DML operations. Do you think so? Is this an appropriate way? My

> experiment gives a performance increase of about 10%.

> 2.If we want the import (of the whole database) to be quick and I want to

> drop all schema objects (using a stored procedure with dynamic SQL) before

> the import, what types of shema objects should be droped in addition to

> tables?

>

> I am using Oracle 8.0.5 for Windows NT4, thanks in advance.

>

> Regards,

> Dino

>

>

>

>