Problem

How to optimize the size of DGN libraries? After putting thousands of levels, element templates and cells into one DGNLIB, the program starts to work very slow.

Solution

There are two options for reducing the size of the DGN library:

Option 1

Unwanted content can be compressed out of dgnlib files by careful use of the Compress Options or the key-in "delete unused" with options as appropriate, for example "delete unused linestyles".
Obviously, you should not use this example command in a dgnlib that actually contains your library linestyles.

Please read more about the compress options here:

·        https://docs.bentley.com/LiveContent/web/MicroStation%20Help-v16/en/CompressOptions.html

Option 2

Although putting everything into one library seems to be the simple approach for a small organization, it is a good practice and recommended workflow to use multiple DGN libraries for different resources.
So if your DGNLIB grows to unmanageable proportions, you might want to divide it into separate .dgnlib files, with different content in each file, for example:

·        Cells
·        Levels
·        Level filters
·        Display styles
·        Line styles
·        Multi-line styles
·        Text styles
·        Dimension styles
·        Detailing symbol styles
·        Standards Checker settings
·        Element templates
·        Ribbon customizations
·        Explorer link sets
·        Print styles

See Also

Creating a DGNLIB Library File for Customizing Microstation's User Interface

Other language sources