Oracle redo commit wait pressure alert


The Redo Commit Wait Pressure alert notifies you when its configured condition is met on Oracle instances so you can investigate and respond.

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Alert summary

  • Platform: Oracle
  • Alert category: Query
  • Default enabled: true
  • Default evaluation frequency: Minute
  • Threshold label: % of DB time
  • Unit: % of DB time

What Mini DBA checks

Mini DBA describes this alert as: Oracle log file sync waits as a percentage of current database time Sustained commit waits mean foreground sessions are waiting for commit confirmation. Check redo log I/O latency, commit frequency, synchronous Data Guard transport, and transaction design. Mini DBA evaluates this alert once a minute so changes are detected quickly. Because duration is used, Mini DBA can avoid treating a single short spike as a full incident when the condition clears quickly.

How this alert helps

This alert measures Oracle log file sync waits as a share of database time. Sustained commit waits mean foreground sessions are waiting for commit confirmation.

When to enable it

Enable it once the instance has a normal workload baseline. It is especially useful on busy OLTP, reporting, and integration systems where resource pressure can quickly become user-visible.

Threshold guidance

Threshold meaning: % of DB time. Major threshold: 25 % of DB time. Minor threshold: 10 % of DB time. Comparison direction: over. Duration is used, so prefer requiring the condition to persist before paging people for transient spikes. For an over-threshold alert, decreasing a threshold makes that severity fire sooner; increasing it tolerates more load or pressure. Set the minor threshold as an early-warning level and the major threshold at the highest acceptable value for the service.

Remediation for an active alert

Compare log file sync with redo-write latency, commit frequency, transaction design, synchronous Data Guard transport, and storage saturation. Correct excessive commit patterns, slow redo storage, or synchronous transport delay; freeing unrelated disk files is not a remedy for commit latency.

Investigation workflow

  1. Record the commit-wait percentage, log file sync latency, transaction rate, and affected workload.
  2. Compare redo-write latency, commit frequency, storage throughput, and synchronous Data Guard transport.
  3. Correlate the change with application releases, transaction-pattern changes, and infrastructure events.
  4. Confirm that commit waits and transaction latency return to baseline.

Avoiding alert noise

If this alert is noisy, check whether the workload naturally has short bursts. Raise the duration or threshold for expected batch windows, but keep a lower route for production systems where user-facing latency matters. Avoid simply disabling the alert until you know whether the noise is caused by threshold choice or by a real capacity trend.

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