To diagnose the specific cause, administrators should query V$ROWCACHE . High values in the GETS and MODS columns for specific parameters (like dc_sequences or dc_users ) point directly to the culprit. Mitigation Strategies
: Oracle includes internal mechanisms to monitor "hot" activity on specific row cache buckets. If a hash chain is accessed too frequently (e.g., reaching a threshold like 1,000,000 gets or exceeding sleep limits), the database may mark the bucket as in the alert log or trace files. The Contention Check Message : A message like kqr row cache contention check gets
Sequences are tracked in the Row Cache. If a sequence has a small or no CACHE value, every NEXTVAL call requires an update to the dictionary row, leading to heavy contention. To diagnose the specific cause, administrators should query
Because the cache was empty, all 10,000 threads saw a at the exact same moment. They all rushed to the database. If a hash chain is accessed too frequently (e
). This cache stores object definitions, such as table structures, column information, and sequence values, as individual rows rather than data blocks. Understanding Row Cache Contention
, the on-call engineer, saw the alert: