add a FAQ entry about :memory: races

Closes mattn#204 Closes mattn#309 Signed-off-by: Tycho Andersen <[email protected]>
tych0 · Jan 26, 2017 · ded1ba6 · ded1ba6
1 parent 7ed900a
commit ded1ba6
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/README.md b/README.md
@@ -68,6 +68,15 @@ FAQ
 
     Yes for readonly. But, No for writable. See #50, #51, #209.
 
+* Why is it racy if I use a `sql.Open("sqlite", ":memory:")` database?
+
+    Each connection to :memory: opens a brand new in-memory sql database, so if
+    the stdlib's sql engine happens to open another connection and you've only
+    specified ":memory:", that connection will see a brand new database. A
+    workaround is to use "file::memory:?mode=memory&cache=shared". Every
+    connection to this string will point to the same in-memory database. See
+    #204 for more info.
+
 License
 -------