documented unsafe mode

Author: JoshuaWise

README.md

@@ -69,6 +69,7 @@ For these situations, you should probably use a full-fledged RDBMS such as [Post
 - [Performance](./docs/performance.md) (also see [benchmark results](./docs/benchmark.md))
 - [64-bit integer support](./docs/integer.md)
 - [Worker thread support](./docs/threads.md)
+- [Unsafe mode (advanced)](./docs/unsafe.md)
 - [SQLite3 compilation](./docs/compilation.md)
 
 # License

deps/sqlite3.gyp

@@ -56,8 +56,7 @@
           'includes': ['defines.gypi'],
         }, {
           'defines': [
-            # These are currently required by better-sqlite3.
-            'SQLITE_USE_URI=1',
+            # This is currently required by better-sqlite3.
             'SQLITE_ENABLE_COLUMN_METADATA',
           ],
         }]

docs/unsafe.md

@@ -0,0 +1,16 @@
+# Unsafe mode
+
+By default, `better-sqlite3` prevents you from doing things that might corrupt your database or cause undefined behavior. Such unsafe operations include:
+
+- Anything blocked by [`SQLITE_DBCONFIG_DEFENSIVE`](https://www.sqlite.org/c3ref/c_dbconfig_defensive.html#sqlitedbconfigdefensive)
+- Mutating the database while [iterating](https://github.com/JoshuaWise/better-sqlite3/blob/master/docs/api.md#iteratebindparameters---iterator) through a query's result set
+
+However, some advanced users might want to use these functionalities at their own risk. For this reason, users have the option of enabling "unsafe mode".
+
+```js
+db.unsafeMode(); // Unsafe mode ON
+db.unsafeMode(true); // Unsafe mode ON
+db.unsafeMode(false); // Unsafe mode OFF
+```
+
+Unsafe mode can be toggled at any time, and independently for each database connection. While toggled on, `better-sqlite3` will not prevent you from performing the dangerous operations listed above.