Changes between Version 10 and Version 11 of NonSqlBackends

Timestamp:

Aug 12, 2009, 2:15:52 PM (15 years ago)

Author:

gumptionthomas

Comment:

--

NonSqlBackends

@@ -36 +36 @@
 = Queries = 
 
-TODO: Let's wait for App Engine to support its new bookmarks mechanism before implementing this (key-based pagination doesn't work in all situations).
+TODO: Let's wait for App Engine to support its new bookmarks mechanism before implementing this (key-based pagination doesn't work in all situations).  (Is there a link to info about app engine bookmarks?  I only found one sentence about cursors on the [http://code.google.com/appengine/docs/roadmap.html official roadmap].)
 
 On App Engine you can only retrieve the first 1000 query results. There needs to be support for "bookmarks" which mark the next starting point.
@@ -43 +43 @@
 
 TODO(mitch?): Find out if this is efficient (even for millions of items) or if it's better to provide bookmarks at a higher level.
+
+== count() ==
+
+query.count() will be problematic since a scalable count() method doesn't exist in app engine (does it exist in SimpleDB?).  Perhaps this will be alleviated by cursors/bookmarks, but I suspect we'll have to address this some other way.  An automatic sharded counter in the manager would allow for an "almost accurate" count in most situations.  It would certainly be good enough for the most popular use case, "how many pages of results do I have?"