sqlite3.oo1.OpfsDb: default to journal_mode=persist, as current tests show it to be marginally faster than truncate/delete in Chrome v109. Also increase default busy_timeout from 2 seconds to 3, admittedly on a whim.

FossilOrigin-Name: d0c8fa30a31c691bc1be5e98d806eeb1e23a8fc6cd54d87e5c1b720aa936e707

1 files changed, 6 insertions, 4 deletions

diff --git a/ext/wasm/api/sqlite3-api-opfs.js b/ext/wasm/api/sqlite3-api-opfs.js
index de7500afa..3099cb486 100644
--- a/ext/wasm/api/sqlite3-api-opfs.js
+++ b/ext/wasm/api/sqlite3-api-opfs.js
@@ -1216,12 +1216,14 @@ const installOpfsVfs = function callee(options){
       sqlite3.oo1.DB.dbCtorHelper.setVfsPostOpenSql(
         opfsVfs.pointer,
         [
-          /* Truncate journal mode is faster than delete or wal for
-             this vfs, per speedtest1. */
-          "pragma journal_mode=truncate;",
+          /* Truncate journal mode is faster than delete for
+             this vfs, per speedtest1. That gap seems to have closed with
+             Chome version 108 or 109, but "persist" is very roughly 5-6%
+             faster than truncate in initial tests. */
+          "pragma journal_mode=persist;",
           /* Set a default busy-timeout handler to help OPFS dbs
              deal with multi-tab/multi-worker contention. */
-          "pragma busy_timeout=2000;",
+          "pragma busy_timeout=3000;",
           /*
             This vfs benefits hugely from cache on moderate/large
             speedtest1 --size 50 and --size 100 workloads. We currently