reload-archived-data-into-the-database-7621fc2.md

Reload Archived Data into the Database

Reloading is optional and should only be used in exceptional cases. The application must decide if a reload is necessary or not.

In the standard process, a reloading of archived data is not required, as archived data and direct access to individual data objects can be performed by using the Read API.

There are two cases which need to be distinguished:

1. Data must be reloaded shortly after deleting data from the database within the archiving process. An example for this case would be if selection criteria were set wrongly for the archiving process.

2. Reload of archived data after a long period of time. In this case it must be ensured that references to and within the reloaded data are still available in database. Furthermore, it needs to be guaranteed that no table key conflicts exist. Since this is not a real error, it's strongly recommended not to reload the data in this case.

The runtime to reload archived data from an external storage system back into the database should be implemented in a central ABAP class. This ABAP class has to register interface IF_ARCH_RELOAD to be able to be selected in an archiving object definition in ADT.

CL_ARCH_RELOAD_API (API to reload archived data)
Method	Parameter	Description
GET_INSTANCE Returns an instance of the delete API. Reference to interface IF_ARCH_RELOAD_API	Importing: IV_ARCHIVING_OBJECT	Name of the archiving object which will be used
	Importing:IV_ARCHIVING_SESSION	Sessions of the archiving object which will be used
	Importing:IV_TESTMODE	Reload program runs in test mode
	Returning:RO_RELOAD_INSTANCE	Instance of the reload API for further processing
GET_SESSIONS_TO_RELOAD Read a data object from an archive file	Importing: IT_DATA_SELECTION	Range on dates on which archive files have been created
	Importing: IT_USER_SELECTION	Range on users which have created archive files
	Importing: IV_ARCHIVING_OBJECT	Archiving object which will be used
	Returning: RT_SESSION_ATTRIBUTES	Archiving sessions' attributes

IF_ARCH_RELOAD_API (Interface to reload archived data)
Method	Parameter	Description
GET_DATA_RECORDS Read records by structure from the current data object	Importing: IV_RECORDS_STRUCTURE	Name of a structure of all data records in the table
	Exporting:ET_DATA_RECORDS	Table containing the data records
GET_NEXT_DATA_OBJECT Read data object from the archive file	Exporting: EV_ARCHIVE_KEY	Archive key according to archive management
	Exporting: EV_END_OF_FILE	Boolean values: TRUE (=’X’) FALSE (= ‘ ‘)
	Exporting: EV_ARCHIVING_SESSION	Sessions of the archiving object which will be used
	Exporting: EV_OBJECT_OFFSET	Offset of data object in the archive
RELOAD_DATA_FOR_OBJECT
RELOAD_DATA_FOR_TABLE Reloading the data of an internal table	Importing: IV_TABLE_NAME	DDIC structure name of an internal table
	Tables: IT_TABLE_NAME
FINALIZE Open archive files will be closed

A typical flow of the archiving reload process would be as follows:

1. Determine archiving sessions which are still available for reload by using the method CL_ARCH_RELOAD_API=> GET_SESSIONS_TO_RELOAD, with filter options on creating user and creation date of the archive file.

2. Create an instance of the reload API and open the archiving reload session for one of the selected archiving sessions by using the method CL_ARCH_RELOAD_API=>GET_INSTANCE.

3. Open the next data object via method GET_NEXT_DATA_OBJECT. If the method returns EV_END_OF_FILE = TRUE (‘X’), continue with step 6 to call the method FINALIZE.

4. Reload the data of the object from the external storage system back into your database tables, either by:

   • Use of the method RELOAD_DATA_FOR_OBJECT

   • Or use of the method RELOAD_DATA_FOR_TABLE. This method needs to be called once for each table.

   • Use of the method GET_DATA_RECORDS. With this method, the result needs to be used to perform your own INSERT statements.

5. Continue with the next data object. See step 3.

6. Finish the archiving reload session by calling the method FINALIZE.

An example coding snippet:

Sample Code:

CONSTANTS: lc_object TYPE if_arch_api_types=>ty_object_name VALUE 'MY_OBJECT'.
DATA: 	lv_test TYPE abap_bool VALUE abap_true,
lt_data TYPE STANDARD TABLE OF my_header_table,
lv_session TYPE sarch_session_number.



 
            " get newest complete archiving session
              DATA(lt_sessions) = cl_arch_reload_api=>get_sessions_to_reload(           iv_archiving_object = lc_object ).
              SORT lt_sessions BY creation_date DESCENDING creation_time DESCENDING.
              READ TABLE lt_sessions ASSIGNING FIELD-SYMBOL(<ls_session>) INDEX 1.
            DATA(lo_reload) = cl_arch_reload_api=>get_instance
( iv_archiving_object =   lc_object
                                                       iv_archiving_session = lv_session
                                                       iv_testmode = lv_test ).
            " read next data object from archive file into internal memory
            DO.
              lo_reload->get_next_data_object( IMPORTING ev_end_of_file = DATA(lv_end_of_file)
                                                         ev_archive_key = DATA(lv_archive_key)
                                                         ev_object_offset = DATA(lv_offset) ).
              IF lv_end_of_file = abap_true.
                EXIT.
              ENDIF.
              " optional: remove
              " read archived data for table ZADK_SFLIGHT
              lo_reload->get_data_records( EXPORTING iv_record_structure = 'MY_HEADER_TABLE'
                                           IMPORTING et_data_records = lt_data ).

              " reload the data into the data base
              lo_reload->reload_data_for_object( ).

              " optional: delete data from customer owned index
              DELETE FROM <my_index_table>
                WHERE archive_key = @lv_archive_key.

            ENDDO.
            COMMIT WORK.
            lo_reload->finalize( ).