Track Current Redo Log Usage with X$KCCCP

Sun, 18 Oct 2026 00:00:00 +0000

Track Current Redo Log Usage with X$KCCCP

Purpose

V$LOG reports a redo log group's allocated size and its status, but it does not report how much of the CURRENT group has actually filled. On a busy instance, that is the number a DBA wants: is the current log close to a switch, or has it barely started filling? V$LOG cannot say.

Oracle's own archiver already answers a version of that question every time it runs. A long-standing third-party reference on the ARCH background process states that when a log switch is forced, ARCH "copies the online redo log a bit more intelligently than how the operating system command cp or copy would do: if a log switch is forced, only the used space of the online log is copied, not the entire log file." That same source names where that count is exposed: "the amount of bytes that have been written to the current online redo log can be determined with x$kcccp." Unlike V$LOG, V$LOGFILE, and V$LOG_HISTORY, X$KCCCP has no published column reference anywhere in either the current 26ai or the 21c Oracle Database documentation on redo log management — it is one of the undocumented fixed tables that sit underneath the documented V$ layer.

X$kcccp on Oracle Scripts

Track Current Redo Log Usage with X$KCCCP

Track Current Redo Log Usage with X$KCCCP

Purpose