What Does opatch apply Do in a Four-Node RAC Cluster?

1Z0-078 By islever Editorial Last updated

Create and administer RAC databases

Short answer

B OPatch apply in a RAC database home applies the patch to the specified Oracle Home on all cluster nodes when run from the first node.

Question

Examine this command executed on the first node of a four-node cluster: $ < DATABASE_ORACLE_HOME >/OPatch/opatch apply 33575673 What does this command do?
  1. It applies a patch to one ORACLE_HOME only on the first cluster node.
  2. It applies a patch to one database ORACLE_HOME on alll cluster nodes. Correct Answer
  3. It applies a patch to all database ORACLE_HOMEs with the same release only on the first cluster node.
  4. It applies a patch to all ORACLE_HOMEs with the same release only on the first cluster node.
  5. It applies a patch to all database ORACLE_HOMEs with the same release on all cluster nodes.

Key Takeaways

This question tests whether you know OPatch's default cluster-aware behavior in a RAC database home, and the trap is assuming that omitting -all_nodes means a local-only patch.

OPatch apply in a RAC database home is cluster-aware: running it on the first node patches the specified Oracle Home on all cluster nodes. This guide establishes why option B is correct and why local-only interpretations miss OPatch's default RAC behavior.

Common mistake: Many candidates choose A (local-only) because the command lacks -all_nodes, but OPatch in RAC mode defaults to applying the patch to all nodes from the first node.

Expert Analysis

Why the Answer Is Correct

The command specifies a database Oracle Home and runs OPatch apply without -local. In a RAC environment, OPatch is cluster-aware: when executed from the first node, it applies the patch to that Oracle Home on all cluster nodes. This matches option B. The "first node" detail matters because OPatch uses the cluster inventory to propagate the patch to every node. Option E is wrong because OPatch targets only the Oracle Home from which it is invoked, not every home of the same release.

Why the Other Options Are Wrong

Option A describes local-only patching, which would require -local (or a non-cluster-aware invocation). Option C and D claim all database Oracle Homes with the same release are patched, but OPatch does not sweep other homes. Option E combines the same-release error with all-node scope. The community comment from Tunglinfo9 reasons that "does not include options for multi-node patching" so it must be local, but that overlooks OPatch's default cluster-aware mode. As 217972f noted, Oracle's patching algorithm defaults to "patching mechanism = All-Node" when no rolling or minimize-downtime option applies.

Community Comment Notes

jackhsu0704 highlighted the -oh option, but the command uses the environment/path, not -oh. lcoleandro pointed to "Cluster-aware Execution (RAC Mode)" and the default behavior of applying to all nodes. The vote split (A:60, B:40) shows this is a common trap; the source key's A reflects the local-only assumption. Oracle documentation and the All-Node default support B. Test_1 simply asserted A without addressing cluster awareness.

Exam Strategy

When an OPatch command in a RAC question lacks -local, default to the cluster-aware answer: one Oracle Home patched on all nodes. Remember that -all_nodes is not required for the default All-Node behavior, and -local is what restricts patching to the current node.

Frequently Asked Questions

Why does OPatch apply patch all nodes when -all_nodes is not specified?

In RAC, OPatch is cluster-aware and defaults to All-Node patching when no rolling or minimize-downtime option is provided.

Does OPatch apply patch all Oracle Homes of the same release in the cluster?

No; it patches only the Oracle Home from which the command is run, not every home of the same release.

More 1Z0-078 FAQ →

Community Votes

A
60%
B
40%

60% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 6 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 6

  1. jackhsu0704 👍 2
    A. It applies a patch to one ORACLE_HOME only on the first cluster node. -oh The oracle home to work on. This takes precedence over the environment variable ORACLE_HOME
  2. lcoleandro 👍 1 Answered B
    we need to consider the typical behavior of OPatch in a clustered environment: Cluster-aware Execution (RAC Mode): The patch can be applied to all nodes in the cluster if executed with the appropriate cluster-aware options or configurations A is incorrect because it does not mention whether the execution is in a cluster-aware mode or not, and typically, in the default mode, OPatch will apply the patch only to the local node, but it will be for the specified ORACLE_HOME. B is the correct answer, as it states that the patch is applied to one database ORACLE_HOME on all cluster nodes, which aligns with the behavior of OPatch when it is cluster-aware. E could also be correct depending on the OPatch configuration and usage of the -all_nodes flag, but typically opatch apply without additional parameters doesn't cover all ORACLE_HOMEs across all nodes by default.
  3. 217972f 👍 1 Answered B
    B as explain in this oracle note: Doc ID 244241.1 "The algorithm used to decide which method is going to be used is the following: If (users specify minimize_downtime) patching mechanism = Min. Downtime else if (patch is a rolling patch) patching mechanism = Rolling else patching mechanism = All-Node "
  4. Tunglinfo9 👍 1 Answered A
    the most accurate answer is A. It applies a patch to one ORACLE_HOME only on the first cluster node. $ <DATABASE_ORACLE_HOME>/OPatch/opatch apply 33575673 does not include options for multi-node patching or rolling patching. This command will apply the patch to the local node only.
  5. jackhsu0704 👍 1
    C. It applies a patch to all database ORACLE_HOMEs with the same release only on the first cluster node.
Show 1 more comment
  1. Test_1 👍 2 Answered A
    I think answer A is correct.

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