Oracle Database / Data Guard & High Availability
Identify a blocking archived-log gap on a standby
A missing redo range can prevent managed recovery from advancing. Inspect the gap view before manually copying files.
Environment and inputs: Oracle Database 19c baseline · SQL*Plus-compatible SQL unless RMAN, DGMGRL, ADRCI or a host shell is specified. Check release, patch level, edition and container first.
Start with this diagnostic
Use the stated SQL, RMAN, DGMGRL or host shell and replace sample names with approved targets. DBA and V$ views need authorized catalog access in the correct container. Do not grant broad privileges for an example.
SELECT thread#, low_sequence#, high_sequence# FROM v$archive_gap;Read the result
The view reports a current blocking gap in the recovery context. Resolving one gap can reveal another; an empty result is not proof of full synchronization.
Resolve and verify
Locate verified copies for the correct thread and incarnation through the supported gap-resolution process. Recheck recovery progress after each correction.
Operational precautions
Do not register logs from another database or assume sequence numbers alone uniquely identify the correct redo.