perf(postgresql): tune postgres settings for improved Nextcloud performance

- shared_buffers: 128MB → 256MB (better hot-data caching)
- effective_cache_size: set to 1GB (planner hint, no memory allocated)
- work_mem: 4MB → 16MB (reduces disk spills in file listing / share queries)
- maintenance_work_mem: 64MB → 256MB (faster VACUUM and index builds)
- wal_buffers: auto → 16MB (reduces WAL write latency)
- checkpoint_timeout: 5min → 15min (spreads checkpoint I/O, reduces spikes)
- random_page_cost: 4.0 → 1.1 (SSD-appropriate; favours index scans)
- effective_io_concurrency: 1 → 200 (SSD-appropriate I/O prefetching)
- autovacuum_vacuum_scale_factor: 0.2 → 0.05 (vacuum sooner on large tables)
- autovacuum_analyze_scale_factor: 0.1 → 0.02 (keep planner stats fresh)

All changes are applied via sed in the existing postgresql.conf modification
block and are idempotent across container restarts (handles both commented
defaults on fresh installs and already-set values on restart).

Agent-Logs-Url: https://github.com/nextcloud/all-in-one/sessions/0456b491-e148-4d26-9dc9-e1df9bfbf5d0

Co-authored-by: szaimen <42591237+szaimen@users.noreply.github.com>

Containers/postgresql/start.sh

@@ -151,23 +151,63 @@ fi
 # Modify postgresql.conf
 if [ -f "/var/lib/postgresql/data/postgresql.conf" ]; then
     echo "Setting postgres values..."
+    PGCONF="/var/lib/postgresql/data/postgresql.conf"
 
     # Sync this with max pm.max_children and MaxRequestWorkers
     # 5000 connections is apparently the highest possible value with postgres so set it to that so that we don't run into a limit here.
     # We don't actually expect so many connections but don't want to limit it artificially because people will report issues otherwise
     # Also connections should usually be closed again after the process is done
     # If we should actually exceed this limit, it is definitely a bug in Nextcloud server or some of its apps that does not close connections correctly and not a bug in AIO
-    sed -i "s|^max_connections =.*|max_connections = 5000|" "/var/lib/postgresql/data/postgresql.conf"
+    sed -i "s|^max_connections =.*|max_connections = 5000|" "$PGCONF"
 
     # Do not log checkpoints
-    if grep -q "#log_checkpoints" /var/lib/postgresql/data/postgresql.conf; then
-        sed -i 's|#log_checkpoints.*|log_checkpoints = off|' /var/lib/postgresql/data/postgresql.conf
+    if grep -q "#log_checkpoints" "$PGCONF"; then
+        sed -i 's|#log_checkpoints.*|log_checkpoints = off|' "$PGCONF"
     fi
 
     # Closing idling connections automatically seems to break any logic so was reverted again to default where it is disabled
-    if grep -q "^idle_session_timeout" /var/lib/postgresql/data/postgresql.conf; then
-        sed -i 's|^idle_session_timeout.*|#idle_session_timeout|' /var/lib/postgresql/data/postgresql.conf
+    if grep -q "^idle_session_timeout" "$PGCONF"; then
+        sed -i 's|^idle_session_timeout.*|#idle_session_timeout|' "$PGCONF"
     fi
+
+    # Increase shared_buffers from the 128MB default for better data caching
+    sed -i "s|^#shared_buffers = .*|shared_buffers = 256MB|" "$PGCONF"
+    sed -i "s|^shared_buffers = .*|shared_buffers = 256MB|" "$PGCONF"
+
+    # Hint to the query planner about available OS page cache (does not allocate memory)
+    sed -i "s|^#effective_cache_size = .*|effective_cache_size = 1GB|" "$PGCONF"
+    sed -i "s|^effective_cache_size = .*|effective_cache_size = 1GB|" "$PGCONF"
+
+    # Increase per-operation sort/hash memory to reduce disk spills for file listing and share queries
+    sed -i "s|^#work_mem = .*|work_mem = 16MB|" "$PGCONF"
+    sed -i "s|^work_mem = .*|work_mem = 16MB|" "$PGCONF"
+
+    # Increase memory for VACUUM, CREATE INDEX, and other maintenance operations
+    sed -i "s|^#maintenance_work_mem = .*|maintenance_work_mem = 256MB|" "$PGCONF"
+    sed -i "s|^maintenance_work_mem = .*|maintenance_work_mem = 256MB|" "$PGCONF"
+
+    # Increase WAL buffers to reduce WAL write latency under concurrent write load
+    sed -i "s|^#wal_buffers = .*|wal_buffers = 16MB|" "$PGCONF"
+    sed -i "s|^wal_buffers = .*|wal_buffers = 16MB|" "$PGCONF"
+
+    # Spread checkpoint I/O over a longer window to reduce spikes
+    sed -i "s|^#checkpoint_timeout = .*|checkpoint_timeout = 15min|" "$PGCONF"
+    sed -i "s|^checkpoint_timeout = .*|checkpoint_timeout = 15min|" "$PGCONF"
+
+    # Tune for SSD storage: random reads are nearly as fast as sequential reads
+    sed -i "s|^#random_page_cost = .*|random_page_cost = 1.1|" "$PGCONF"
+    sed -i "s|^random_page_cost = .*|random_page_cost = 1.1|" "$PGCONF"
+
+    # Allow the kernel to issue more concurrent I/O prefetch requests (suitable for SSDs)
+    sed -i "s|^#effective_io_concurrency = .*|effective_io_concurrency = 200|" "$PGCONF"
+    sed -i "s|^effective_io_concurrency = .*|effective_io_concurrency = 200|" "$PGCONF"
+
+    # Trigger autovacuum earlier on large Nextcloud tables (e.g. oc_filecache, oc_activity)
+    # to prevent table bloat accumulating before the default 20% threshold is reached
+    sed -i "s|^#autovacuum_vacuum_scale_factor = .*|autovacuum_vacuum_scale_factor = 0.05|" "$PGCONF"
+    sed -i "s|^autovacuum_vacuum_scale_factor = .*|autovacuum_vacuum_scale_factor = 0.05|" "$PGCONF"
+    sed -i "s|^#autovacuum_analyze_scale_factor = .*|autovacuum_analyze_scale_factor = 0.02|" "$PGCONF"
+    sed -i "s|^autovacuum_analyze_scale_factor = .*|autovacuum_analyze_scale_factor = 0.02|" "$PGCONF"
 fi
 
 do_database_dump() {