2012

Table Of Contents
Track External Reference Operations (Log File)
To use the xref log file
1 At the Command prompt, enter xrefctl.
2 Enter 1 to turn logging on or 0 to turn logging off.
3 Press Enter.
Logging is off by default.
Increase Performance with Large Refer-
enced Drawings
There are several features that can improve performance when dealing with
large referenced drawings.
Overview of Demand Loading
The program uses demand loading and saving drawings with internal indexes
to increase performance with large referenced drawings that have been clipped,
or that have many objects on frozen layers. With demand loading, only the
data from the reference drawing that is necessary to regenerate the current
drawing is loaded into memory. In other words, referenced data is read in on
demand.
Demand loading works in conjunction with the INDEXCTL, XLOADCTL, and
XLOADPATH system variables.
Unload Xrefs in Large Drawings
When a referenced drawing (xref) is unloaded from the current drawing, the
drawing opens much faster and uses less memory.
The xref definition is unloaded from the drawing file, but the internal pointer
to the referenced drawing remains. The xref is not displayed, and nongraphical
object information does not appear in the drawing. However, you can restore
all the information by reloading the xref. If XLOADCTL (demand loading) is
set to 1, unloading the drawing unlocks the original file.
738 | Chapter 11 Share Data Between Files