GUI Application Guide

The DaRT Reader GUI provides a user-friendly interface for: - Loading DaRT extracts - Viewing extract metadata - Exporting to databases - Exporting to CSV files

Prerequisites

You need a valid license key to start. Go to the File menu and select Settings:

In Settings there is a field called License Key. Enter your key and press save.

Loading DaRT extracts

To load a DaRT extract first make sure that the directory file and the payload files are in the same directory. Then either drag and drop the directory file into the Drag & Drop field or click on the field. If you click on the Drag & Drop field, a file selection dialog appears. Choose the directory file and after a short time you will see metadata about the extract.

You see some metadata of the extract: The user who created the extract, when it was created, the fiscal year of the extract, the DaRT release and SAP system. You also see the payload files of the extract and their expected file size (i.e. the file size stored in the extract) and the actual file size on the file system.

Seeing what is in the extract

After loading the extract, click on the Segments button on the top right. You see all the segments that are contained in the extract.

You see the segment name, the description of the segment and the number of records contained in the extract. The information is in the language of the extract. By clicking on any of the rows, you see the field names, their description and their ordering in the segment.

Writing the extract

Navigate to the segment overview. Select the segments that you want to write. On the top right there are two buttons Write to file and Write to database.

Writing to a database

Click on the button Write to database and a window appears. You can select a database that you want to write to:

• SQLite
• H2
• PostgreSQL
• MySQL
• SQL Server
• DuckDB
• MS Access

For databases that create a single file on the file system (SQLite, H2, DuckDB, MS Access), you have the option to select a file on the filesystem. This file does not need to exist yet.

For these databases, you can alternatively, and for the other databases you must, enter a connection string. For the databases for which you must enter a connection string, it is understood that there is a running server process that DaRT Reader can connect to.

Please see the documentation of the respective JDBC drivers or database system on how to form the connection string:

Database	Documentation
SQLite	https://sqlite.org/c3ref/open.html
H2	https://www.h2database.com/html/features.html#database_url
PostgreSQL	https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING
MySQL	https://mariadb.com/docs/connectors/mariadb-connector-j/about-mariadb-connector-j#connection-strings
SQL Server	https://learn.microsoft.com/en-us/sql/connect/jdbc/building-the-connection-url?view=sql-server-ver17
DuckDB	https://duckdb.org/docs/stable/clients/java
MS Access	https://ucanaccess.sourceforge.net/site.html#examples

ℹ️ Note: If you enter a connection string, leave out the protocol prefix. For example, in jdbc:postgresql://localhost:5432/mydb, leave out jdbc:postgresql:.

Click start and the writing process starts. The progress is indicated by a progress bar. You have the option to halt or abort the writing process by clicking on the appropriate buttons.

Writing CSV files

In the segment overview click the button Write to file. You are prompted to select a directory to write to. Once you selected it the CSV files will be created according to the schema <segment-name>.csv. Please make sure that the directory does not contain files that are to be created. Otherwise you will receive an error message and the writing will abort.

Changing the settings

You can change how DaRT Reader connects to the database and how much data is written at the same time. On the File menu select Settings.

Here is a description of the setting parameters:

Method	Description
Number of connections	The number of database connections. This controls the number of parallel write processes.
Chunk size per connection	The number of records written per connection.
Connection timeout	The maximum number of milliseconds that a client will wait for a connection.
Max lifetime	The maximum lifetime of a connection in the connection pool in milliseconds.
Validation timeout	Maximum milliseconds after a connection is declared dead.
License key	A license key that you retrieved during the onboarding process.

You can tradeoff higher throughput (size divided by time) with more memory consumption if you increase the Number of connections or the Chunk size per connection parameter. With number-connections = 5 and chunk-size-per-connection = 5000, batches of 5000 records will be written in 5 parallel connections amounting to 25,000 records. If the throughput is too high, you might get Out of memory errors. If this happens, you have to increase the memory of the JVM.

Increasing memory of the JVM

From the installation directory, follow the relative path app on Windows and Contents/app on Mac OS and open the file DaRT Reader.cfg.cfg. At the end of this file in a section called [JavaOptions], make the following additions:

java-options=-Xms512m
java-options=-Xmx4g

This adds 512mb initial heap size and 4g maximum heap size. Increase these parameters if the JVM process runs out of memory.

Viewing the log

In the File menu click Help > View Logs

You can select either the logs of the GUI or of the CLI by selecting an appropriate log file in the dropdown. DaRT Reader uses log rotation. When a file is larger than 5mb a new file is created, up to three files after which the oldest file is deleted.

Click Refresh to trigger a new reading of the log files and Open Directory to reveal the log files in the file system.