In a new KB, the installed system tables contain the default values that G2 provides for each system table attribute. If you change one or more system table attributes and then save your KB, the modified system tables are saved as a permanent part of the KB's knowledge. G2 installs these system tables when next you load the KB.
If the current KB is modularized, indicating that it consists of one or more KB modules, each module has an associated set of system tables, though only one set is installed. Two reasons why modules include their own set of system tables are:
You can replace one set of installed system tables with another by merging in a KB. If you merge a KB module into an existing KB, one of the options on the
KB Merge menu is:
You can also start G2 with one or more optional command line options that let you specify a module map file or a module search path. Using either of these command line options can affect the values of the Module Information system table.
Changing System Tables Interactively
When you select a system table, G2 displays its attributes and the values for those attributes. Unlike most items, system tables are not associated with a workspace and display directly on the Gensym background area.
Changing System Table Values Programmatically
You can use the
conclude action to change the value of most system table attributes. For example, to change the default font size for the Text Editor, enter a statement such as: