A java.lang.OutOfMemory error may occur during viewing of large diagrams, large design files or other memory intensive tasks. By default DbWrench allocates approximately 128 MB of memory for itself, this maybe inadequate for larger designs. More memory can be allocated using the following procedure.

Navigate to the DbWrench installation folder. Usually dbwrench2.

Then navigate to the etc subfolder.

Open the dbwrench2.conf file in an editor. See the screen-shot below.

In the default_options line, change -J-Xmx256m to -J-Xmx512m.

To allocate an amount other than 512MB, just use that number instead.

This error seems to occur mostly on Windows 7 machines. The JDK (Java Development Kit) is not in the location DbWrench expected. This can be fixed by editing a DbWrench .conf file.

Find the location of your JDK.

Then open the dbwrench2.conf file in an editor. This file is located in the etc subfolder of the DbWrench installation folder.

Specify your path in the line circled in the screen-shot below. An example path would be something like C:\Program Files\Java\jdk1.6.0_13. Make sure to remove the '#' at the start of the line.

Restart DbWrench.

Yes. As you are typing in an editor, hit CTRL-Space to bring up the code completion window.

You can see the Java version DbWrench is using in the About dialog box within DbWrench.

To switch Java versions, open the dbwrench2.conf file in an editor. This file is located in the etc subfolder of the DbWrench installation folder.

Specify your path in the line circled in the screen-shot below. An example path would be something like C:\Program Files\Java\jdk1.6.0_13. Make sure to remove the '#' at the start of the line.

Restart DbWrench.

Some datatypes, particularly those that are specific to a particuler database are disabled by default. You can enable them by going to the Preferences panel, selecting Data Types in the list on the left and then enabling/disabling data types.

How can I specify that forward engineer scripts be executed within a transaction?

Go to the Preferences panel, select Forward Engineering in the list on the left then make sure Use Transactions is selected.

Two ways to do this:

One way: Right click in the gray margin to the left of the editor window. In the popup menu select to enable or disable either of these options.

Second Way: From the main menu use the View menu to enable or disable either option.

DbWrench is built on the NetBeans Application Framework. Building on this pure Java framework allows DbWrench to run on Windows, Mac, Linux and several other operating systems.

Select one of the 'generic' connections listed at the bottom of the Connections combobox before generating the forward engineer script.

This usually indicates that you running an older version of the Java Runtime Environment (JRE). You can upgrade your JRE for free at www.java.com.

Forward Engineer filters out connections that do not have the same 'Database' name as the database name of the current DbWrench design. This happens if connection filtering is enabled in Preferences. To prevent filtering, from main menu go Edit | Preferences. Then select Forward Engineer in the list on the left side. Make sure the Filter Connection List by Database Name is not selected.

MySQL docs explain the problem in more detail here (Section 20.4.5.3.1). Generally it's a privileges problem.

Specify the instance name in the Optional Parameters field as shown in this example.

DbWrench uses the jTDS JDBC driver to connect to SQL Server. This error occurs if the SQL Server installation is using Windows Authentication instead of SQL Server Authentication. Switching authentication methods will solve this problem. If this is not possible, installing the ntlmauth.dll native library will also address this problem. This dll is bundled in the jTDS zip file which can be downloaded for free from here. The zip file also includes readme.sso which has installation instructions for this dll.

Here is an outline of the installation instructions:
• From the zipped folder, locate the version of ntlmauth.dll that is appropriate for your system. For example, 32-bit version or 64-bit version.
• Copy this dll to any folder on your system path. You can view your system path by typing echo %path% at the command prompt.
• You may need to restart your system.

Also see the sample connection configurations

See the above question:

Connecting to a MS SQL Server installation results in 'I/O Error: SSO Failed: Native SSPI library not loaded'.

If the SHIFT key is down while the mouse is over a diagram panel, the 'hand' cursor should appear. Keeping the SHIFT key down, the diagram will 'slide' or translate as the mouse is moved.

This functionality should also be accessible with either:

• ALT + mouse click
• double click

A unique index on that column will supercede the UNIQUE flag value. So make sure to remove any unique indexes on that column in addition to unchecking the UNIQUE flag.

Generally a user's home directory is used as the current working directory. So adding the line 'cd "$progdir/.." to the 'dbwrench2' shell script, as shown belown, will change the working directory to the application directory. The shell script is located in the 'bin' directory.