more auth logging

README.md

@@ -211,6 +211,80 @@ Validate connectivity before starting vCTP:
 psql "postgres://vctp_user:change-this-password@db-hostname:5432/vctp?sslmode=disable"
 ```
 
+### PostgreSQL tuning baseline (20 vCPU / 64 GB host)
+If your PostgreSQL instance is still running near-default settings, use this as a practical starting profile for vCTP workloads (hourly ingest + daily/monthly aggregation).
+
+Choose one profile:
+- Dedicated DB host (PostgreSQL is the primary service on this machine): use the `dedicated` values.
+- Shared host (vCTP app + PostgreSQL on same machine): use the `shared` values.
+
+Recommended `postgresql.conf` starting points:
+
+```conf
+# Memory
+shared_buffers = 16GB                 # dedicated
+# shared_buffers = 12GB               # shared
+effective_cache_size = 48GB           # dedicated
+# effective_cache_size = 36GB         # shared
+work_mem = 32MB                       # dedicated
+# work_mem = 16MB                     # shared
+maintenance_work_mem = 2GB            # dedicated
+# maintenance_work_mem = 1GB          # shared
+
+# WAL / checkpoints
+wal_compression = on
+checkpoint_timeout = 15min
+checkpoint_completion_target = 0.9
+max_wal_size = 16GB
+min_wal_size = 2GB
+
+# Parallelism and connections
+max_connections = 120
+max_worker_processes = 20
+max_parallel_workers = 20
+max_parallel_workers_per_gather = 4
+max_parallel_maintenance_workers = 4
+
+# Planner / IO (SSD/NVMe)
+random_page_cost = 1.1
+effective_io_concurrency = 200
+default_statistics_target = 200
+
+# Autovacuum for high-write canonical tables
+autovacuum_max_workers = 6
+autovacuum_naptime = 30s
+autovacuum_vacuum_scale_factor = 0.02
+autovacuum_analyze_scale_factor = 0.01
+autovacuum_vacuum_cost_limit = 2000
+
+# Useful diagnostics
+track_io_timing = on
+log_temp_files = 32MB
+```
+
+Apply and validate:
+- Reload config (`SELECT pg_reload_conf();`) or restart PostgreSQL if required by your platform.
+- Confirm active values with:
+
+```sql
+SHOW shared_buffers;
+SHOW effective_cache_size;
+SHOW work_mem;
+SHOW maintenance_work_mem;
+SHOW max_wal_size;
+SHOW autovacuum_vacuum_scale_factor;
+```
+
+After tuning, rerun the canonical benchmark and compare against your pre-tuning snapshot:
+
+```shell
+vctp -settings /path/to/vctp.yml -benchmark-aggregations -benchmark-runs 3
+```
+
+Notes:
+- `work_mem` is per sort/hash operation, not per session; avoid setting it too high globally.
+- Keep `settings.scheduled_aggregation_engine: go` as default unless repeated production-scale benchmarks show SQL is consistently faster on your canonical Postgres data.
+
 PostgreSQL migrations live in `db/migrations_postgres`, while SQLite migrations remain in
 `db/migrations`.