Generic PostgreSQL advice doesn’t work on RDS. PGFlare specialises in the RDS-specific performance constraints that affect parameter groups, storage autoscaling, vacuum scheduling, and the PostgreSQL 16.9+ query planner changes that most teams don’t know to look for. Fixed-fee sessions. Real fixes. Same day.
See Session Pricing →AWS RDS introduces constraints and defaults that differ significantly from self-managed PostgreSQL. The following issues are endemic to RDS deployments and are what PGFlare is purpose-built to diagnose and remediate.
RDS default parameter groups are conservative. work_mem, shared_buffers,
max_parallel_workers, and effective_cache_size are almost always
wrong for your instance class. We recalibrate against your actual workload and instance size.
RDS autovacuum cost delay parameters were tightened in 16.9. Without table-level overrides, high-write tables accumulate bloat faster than default autovacuum can clear it, leading to transaction ID wraparound risk and page scan overhead.
RDS storage autoscaling events pause I/O. Combined with a vacuum backlog, this causes query latency spikes that look like query plan regressions but are actually storage events. We identify and separate these causes in every diagnostic.
The 16.x planner improved statistics gathering and parallel query decisions. This means
queries that performed acceptably on 15.x can regress on 16.9 without any code changes.
We identify plan regressions using pg_stat_statements mean_exec_time deltas.
RDS has hard connection limits by instance class. Applications using unbounded connection
pools hit max_connections under peak load, causing cascading timeouts. We
right-size PgBouncer configuration for your traffic patterns.
Unused indexes on high-write RDS tables silently increase write latency and consume
storage I/O budget. We identify every unused index and build a safe removal plan using
pg_stat_user_indexes data.
PostgreSQL 16.9 introduced meaningful changes to the query planner, autovacuum cost parameters, and parallel query scheduling. On RDS, these interact with AWS-specific defaults in ways that generic PostgreSQL documentation doesn’t cover. Teams upgrading from 15.x to 16.9 without specialist review regularly encounter:
max_parallel_workers_per_gather changespg_stat_statements revealing latency regressions invisible before
16.xPGFlare's analysis models are specifically calibrated for RDS PostgreSQL 16.9+, covering all of these regression patterns in every diagnostic engagement.
PGFlare connects exclusively via a read-only IAM role scoped to PostgreSQL performance statistics
views: pg_stat_statements, pg_stat_bgwriter, pg_locks,
and pg_stat_user_tables. We cannot read, write, or access application data under
any circumstances. No agents are installed. No schema changes are made. Your data stays in your
VPC throughout.
View the full IAM setup
guide →
A UK SaaS platform running RDS PostgreSQL 16.9 on db.r6g.2xlarge was experiencing
P95 query latencies of 4.2 seconds on their primary reporting endpoint. Engineers had already
added two additional indexes without improvement. PGFlare's diagnostic identified:
work_mem was set to the RDS default of 4MB — the sort operation in the query required
18MB
After a Remediation+ session: autovacuum reconfigured, bloat cleared with
VACUUM FULL CONCURRENTLY
on a replica, work_mem adjusted at the role level. P95 latency fell to 180ms within 6 hours.
Read more case studies →
Fixed-fee sessions from £497. No retainer, no agents, no schema changes. Limited consultation spots available each month.
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