Oracle Database / Data Guard & High Availability
Check standby redo log layout against the primary threads
Insufficient or unsuitable standby redo logs can interfere with real-time transport and apply. Inspect group size and thread coverage.
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 group#, thread#, bytes, status FROM v$standby_log ORDER BY thread#, group#;Read the result
The layout must be compared with the source online redo groups and the supported sizing and group-count requirements, including all relevant RAC threads.
Resolve and verify
Have the DBA plan missing groups or size corrections through a supported maintenance change. Validate real-time redo reception afterward.
Operational precautions
Do not drop an active standby redo group or assume one thread's layout covers a RAC source.