diff --git a/schema/index.txt b/schema/index.txt
new file mode 100644
index 0000000..e3fedbd
--- /dev/null
+++ b/schema/index.txt
@@ -0,0 +1,11 @@
+// -*- js -*-
+
+// connect to db
+use content
+
+// create single index on column sha1
+// unique: key must be unique
+// sparse: only return result for which the index exists
+// background: build asynchronously
+db.content.createIndex({ 'sha1': 1 },
+                       { 'unique': true, 'sparse': true, 'background': true})