AUL (MyDUL) can recover the data to dump file by setting the output style, the character set and the national character set. As following, 871 is the UTF8 character set id.
AUL> SET OUTPUT_STYLE DMP
Current OUTPUT_STYLE is : DMP
AUL> SET CHARSET 871
Current CHARSET is : 0x0367
AUL> SET NLSCHARSET 871
Current NLSCHARSET is : 0x0367
AUL> UNLOAD TABLE SCOTT.EMP TO EMP.dmp
......
The basic target of AUL/MyDUL is to recover data, so the dump file contains the data you required. When you use exp utility to export a table from Oracle database, the dump file contains the full syntax of recreate the table, indexes, all the constraints, triggers of the target table. But in the dump file of AUL/MyDUL, it just contains a basic create table SQL, it will not contain the following:
1, The storage definition of the table.
2, The partition & sub-partition definition.
3, The indexes associated with the table.
4, The constraints associated with the table except the "NOT NULL".
5, The default values defined on the columns.
6, The triggers defined on the table.
7, The privileges granted to other schema.
And the export schema of the dmp file is always "mydul", one dmp file for each table, the dump format version is Oracle 8.1.7, you must use exp version 8.1.7 or higher to import it to new database. And no multiple dmp file support as exp do for huge table. Some customers have asked me this question. Maybe I will enhance it in later releases. You should use the "fromuser" option and "touser" option to import the data into new database.
imp ... fromuser=mydul touser=...
According to my experience, the dump format is not strong as text format recovery, if there are corruptions in the data files, the dump file may not be fully correct.
Comments (1)
You can query the database character set id with the following query.
select nls_charset_id(value) ID,
VALUE CHARSET_NAME
from v$nls_valid_values
where parameter = 'CHARACTERSET'
AND nls_charset_id(value) IS NOT NULL
AND VALUE LIKE '%UTF8%'
/
Posted by anysql | October 11, 2007 5:25 PM