From 19d8c7d0fd407217ca8f0f250a09dba38012beb0 Mon Sep 17 00:00:00 2001
From: jamey <jamey@server.jamey.stream>
Date: Sun, 22 Feb 2026 09:23:41 +0000
Subject: [PATCH] tune SQLite PRAGMAs for production

Add journal_size_limit (64MB), default_transaction_mode: :immediate,
and mmap_size (128MB) across dev, test, and prod configs. Benchmarks
showed IMMEDIATE mode eliminates transaction upgrade BUSY errors and
mmap improves read throughput.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 config/dev.exs     | 3 +++
 config/runtime.exs | 5 ++++-
 config/test.exs    | 5 ++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/config/dev.exs b/config/dev.exs
index a9e9d81..15877c2 100644
--- a/config/dev.exs
+++ b/config/dev.exs
@@ -6,6 +6,9 @@ config :berrypod, Berrypod.Repo,
   pool_size: 5,
   journal_mode: :wal,
   busy_timeout: 5000,
+  journal_size_limit: 67_108_864,
+  default_transaction_mode: :immediate,
+  custom_pragmas: [mmap_size: 134_217_728],
   stacktrace: true,
   show_sensitive_data_on_connection_error: true
 
diff --git a/config/runtime.exs b/config/runtime.exs
index e2c98c1..27f4b13 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -32,7 +32,10 @@ if config_env() == :prod do
     database: database_path,
     pool_size: String.to_integer(System.get_env("POOL_SIZE") || "5"),
     journal_mode: :wal,
-    busy_timeout: 5000
+    busy_timeout: 5000,
+    journal_size_limit: 67_108_864,
+    default_transaction_mode: :immediate,
+    custom_pragmas: [mmap_size: 134_217_728]
 
   # The secret key base is used to sign/encrypt cookies and other secrets.
   # A default value is used in config/dev.exs and config/test.exs but you
diff --git a/config/test.exs b/config/test.exs
index 57ab11b..58c7e6f 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -15,7 +15,10 @@ config :berrypod, Berrypod.Repo,
   journal_mode: :wal,
   busy_timeout: 15_000,
   queue_target: 5_000,
-  queue_interval: 10_000
+  queue_interval: 10_000,
+  journal_size_limit: 67_108_864,
+  default_transaction_mode: :immediate,
+  custom_pragmas: [mmap_size: 134_217_728]
 
 # We don't run a server during test. If one is required,
 # you can enable the server option below.