Oracle Bug 32043701

Bug Description

The bug described in Bug 32043701 involves row cache locks for sequences in Real Application Clusters (RAC) due to the S-optimization feature for dc_sequences. This bug creates locks on the data dictionary rows, primarily to serialize changes to the data dictionary and wait for a lock on a data dictionary cache.

How to Fix
To fix this bug, the workaround is to turn off the S-optimization feature for the sequences (dc_sequences) cache. This can be achieved by explicitly listing the S-optimized enqueue types in the _lm_share_lock_restype config parameter and skipping the enqueue type QN. The specific setting to address this bug is to set _lm_share_lock_restype=’LNQAQBQCQDQEQFQGQHQIQJQKQLQMQOQPQQQRQSQTQUQVQWQXQYQZ’. It is crucial to ensure that this setting has the same value in all instances to resolve the issue reported in bug 32043701 effectively.