DB Link Propagation and SCN Headroom: Understanding the Impact of January 2012 CPU/PSU Patches
SCN Basics
SCN (System Change Number) is a monotonically increasing logical timestamp within an Oracle database, essential for recovery, transaction ACID, consistent reads, and distributed transactions. Internally, a 48-bit SCN is split into a 32-bit low part (scn base) and a 16-bit high part (scn wrap), giving a maximum value of 2^48 (approxi ...
Posted on Mon, 31 Aug 2026 16:27:19 +0000 by hcoms