db, refactor: performance tuning for SQLite.

Author: xicilion

fibjs/src/db/sql/SQLite.cpp

@@ -53,6 +53,8 @@ result_t SQLite::open(const char* file)
 
     obj_ptr<NArray> retVal;
     cc_execute("PRAGMA journal_mode=WAL;", retVal);
+    cc_execute("PRAGMA synchronous=normal;", retVal);
+    cc_execute("PRAGMA temp_store=memory;", retVal);
 
     m_file = file;
 

test/db_test.js

@@ -1346,7 +1346,7 @@ describe("db", () => {
             var synchronous = conn.execute("PRAGMA synchronous;")[0].synchronous;
             conn.close();
 
-            assert.equal(synchronous, 2);
+            assert.equal(synchronous, 1);
         });
 
         it("check journal mode", () => {