Use PROSTRCT STATISTICS reports to periodically monitor the High Water Mark for Storage Areas on all databases pre OpenEdge 10.1B and post 10.1B that do not use Type II Storage Areas.
Refer to Article
When does the 2 billion rowid limit per Storage Area apply? Example: The following Area has 37 GB remaining
Database Block Usage for Area: <Area Name>
Active blocks: 28099782
<< Current High Water Mark = 214 GB Data blocks: 28099782
Free blocks: 0
Empty blocks: 74
Total blocks: 28099856
Extent blocks: 16
Records/Block: 64
<< MAXAREA 256 GB = (2^31-1)/64 * 8 K dblocksize Cluster size: 1
<< Type I Storage Area