Data Monitoring / PostgreSQL Monitoring
PostgreSQL: Cache hit ratio context
A high cache hit ratio accompanies slow queries. Compare the ratio with query latency, physical I/O and workload type.
Environment and inputs: PostgreSQL 18 documentation baseline; views, extensions and permissions vary across versions and managed services.
Failure scenario
A high cache hit ratio accompanies slow queries. Confirm the cause before choosing a fix.
Evidence to collect
Compare the ratio with query latency, physical I/O and workload type. Record the time, affected scope and a healthy comparison interval.
Fix the confirmed cause
Investigate the actual bottleneck; a favorable cache ratio alone does not prove efficient execution. Write the expected result first. Change one relevant setting at a time.
Check the result and hand over
Repeat the check for cache hit ratio context using the same scope and a representative interval. Check that the symptom is resolved, expected records are present and downstream results are correct. If coverage, correctness or latency worsens, restore the recorded configuration through the agreed rollback process.
Scope and precautions
Prefer read-only access and limit queries to the relevant period or dataset. This example has not been tested on your systems. Test changes in an approved environment. Keep credentials and sensitive data out of shared evidence.