Fixing Buffer Cache Lock Contention in PeopleSoft Batch Jobs (Oracle DB 19c on OLVM)

Symptom & Error Diagnostic

Under peak concurrent batch operations (e.g. financial close or payroll calculations), PeopleSoft batch process batch_process_01 stalls at 95% execution.

Database alert logs record the following wait events:

ORA-08102: index key not found, obj# 89412, file 14, block 4012
Wait event: latch: row cache objects (Duration: 420s)

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Root Cause Analysis

Buffer cache latch contention occurs when multiple batch instances contend for row cache objects on PS_JOB_RUN_CNTL. Index key corruption or fragmentation during concurrent write/update transactions starves the Oracle SGA shared pool memory allocation.

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Step-by-Step Resolution Runbook

Step 1: Kernel & Memory Parameter Adjustment

Run the following commands on the primary Oracle Linux host node:

# Set swappiness to 10 and adjust hugepages
sysctl -w vm.swappiness=10
sysctl -w vm.nr_hugepages=2048

# Persist settings in /etc/sysctl.conf
echo "vm.swappiness=10" >> /etc/sysctl.conf
echo "vm.nr_hugepages=2048" >> /etc/sysctl.conf

Step 2: Online Index Rebuild

Execute online rebuild on the affected PeopleTools index:

-- Rebuild index online without locking batch tables
ALTER INDEX PS_JOB_RUN_CNTL REBUILD ONLINE PARALLEL 4;
ALTER INDEX PS_JOB_RUN_CNTL NOPARALLEL;

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Anonymized Collector Diagnostic

Run our local CLI script to verify SGA memory and index health without transmitting sensitive data:

node ./scripts/collector/dbpros-sanitize-collect.js --input-log /u01/app/oracle/diag/rdbms/orcl/trace/orcl_ora_10492.trc

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