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 DBEXTRACT Command 

With this Loader command, you can control the unloading of all application data and the corresponding database catalog information.

Syntax

<dbextract_statement> ::=
DBEXTRACT [<
configurationstream_spec >] <catalogoutstream_spec > <dataoutstream_spec > [<packagestream_spec >] [<restart>]

You can also use the keywords EXTRACT DB instead of the keyword DATAEXTRACT.

Prerequisite

THE DBEXTRACT command can only be executed by the database system administrator (SYSDBA user) .

Use

The DBEXTRACT command combines the commands CATALOGEXTRACT ALL and TABLEEXTRACT ALL. You can use external backup tools to unload data.

Data Streams: <catalogoutstream_spec> and <dataoutstream_spec>

At least two data streams must be created when unloading:

·        Data stream for the database catalog definitions <catalogoutstream_spec>

·        Data stream for the application data <dataoutstream_spec>

The system table TRANSFORMATIONMODEL and other system tables are filled.

Exclude Tables from Unload: <configurationstream_spec>

·        Unless you specify the data stream <configurationstream_spec>, all the application data is unloaded.

·        By specifying a data stream <configurationstream_spec>, you can exclude the application data of selected tables from the unload process<dataoutstream_spec>. The tables must be identified in the data stream by the specification of their owner and the table name.
The information about which tables are not unloaded is stored in the system tables. You can display this information by displaying the system table TRANSFORMATIONPACKAGES. The tables excluded from the unload of the application data have the value TRUE in the column EXCLUDE.

The database catalog entries (<catalogoutstream_spec>) of all tables are always unloaded, regardless of the restrictions made in <configurationstream_spec>.

Unloading the System Table TRANSFORMATIONPACKAGES: <packagestream_spec>

·        When you specify a data stream <packagestream_spec>, all entries of the table TRANSFORMATIONPACKAGES are unloaded to this data stream. You are recommended to use this option to create a log of the unload process.

·        If you do not specify the data stream <packagestream_spec>, the system table TRANSFORMATIONPACKAGES is not unloaded.

Result

The application data and the database catalog are unloaded to the data streams <dataoutstream_spec> and <catalogoutstream_spec>.

If necessary, all entries of the table TRANSFORMATIONPACKAGES are unloaded in the data stream <packagestream_spec>.

You can use the corresponding DBLOAD command to restore the database catalog and the application data.

Errors

The unload process cannot be successfully completed. In this case, the Loader logs the cause of the error in the log file.

The values PACKAGEGUID and CLIENTNODE are also written to the log file. The PACKAGEGUID is required if you want to restart the unload process.

 

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