# =============================================================================
# postgres/fhir/postgresql.conf
# PostgreSQL 15 configuration tuned for HAPI FHIR JPA workload.
# Container memory limit: 2GB (set in docker-compose deploy.resources).
#
# Tuning methodology:
#   shared_buffers     = 25% of container RAM
#   effective_cache    = 75% of container RAM
#   work_mem           = (RAM - shared_buffers) / (max_connections * 2)
#   maintenance_work_mem = 10% of RAM
#
# For 2GB container:
#   shared_buffers       = 512MB
#   effective_cache_size = 1536MB
#   work_mem             = 8MB  (conservative — many parallel queries)
#   maintenance_work_mem = 200MB
# =============================================================================

# Connection settings
# max_connections must be > pgBouncer pool_size to leave headroom for
# superuser connections (Flyway, maintenance).
# pgBouncer pool_size=20 + 5 superuser = 25 total.
max_connections = 30
superuser_reserved_connections = 3

# Memory
shared_buffers       = 512MB
effective_cache_size = 1536MB
work_mem             = 8MB
maintenance_work_mem = 200MB

# Write performance
# wal_buffers: 16MB is good for write-heavy workloads
wal_buffers              = 16MB
checkpoint_completion_target = 0.9
# synchronous_commit=on: do not disable — data integrity is non-negotiable
# for a national health record system.
synchronous_commit       = on

# Query planner
# random_page_cost=1.1: appropriate for SSD storage (not spinning disk).
# If storage is HDD, set to 4.0.
random_page_cost    = 1.1
effective_io_concurrency = 200

# Logging — errors and slow queries only
# log_min_duration_statement: log queries taking >500ms.
# Adjust down to 100ms if you want more visibility during initial deployment.
log_destination          = stderr
logging_collector        = off   # Docker captures stderr directly
log_min_messages         = WARNING
log_min_error_statement  = ERROR
log_min_duration_statement = 500
log_line_prefix          = '%t [%p] %u@%d '
log_checkpoints          = on
log_connections          = off   # pgBouncer already logs connections
log_disconnections       = off
log_lock_waits           = on
log_temp_files           = 0

# Autovacuum — keep defaults but tune for HAPI's high-write token tables
autovacuum                    = on
autovacuum_max_workers        = 3
autovacuum_naptime            = 30s
# HFJ_SPIDX_TOKEN is written heavily — lower threshold for autovacuum
autovacuum_vacuum_scale_factor  = 0.02
autovacuum_analyze_scale_factor = 0.01

# Timezone — all timestamps in UTC
timezone = 'UTC'
log_timezone = 'UTC'

# Locale
lc_messages  = 'en_US.UTF-8'
lc_monetary  = 'en_US.UTF-8'
lc_numeric   = 'en_US.UTF-8'
lc_time      = 'en_US.UTF-8'

# Statistics
track_io_timing   = on
track_counts      = on